Representing Light

' ClaroOscuro lighting design' ClaroOscuro lighting design

Representing Light taking hints from fine arts

A l f r e d o G a r c i a - G a u r a v J a i n ' ClaroOscuro lighting design

' ClaroOscuro lighting design' ClaroOscuro lighting design' ClaroOscuro lighting design' ClaroOscuro lighting design

REPRESENTING LIGHT: taking hints from fine arts

By

Alfredo Garcia

Gaurav Jain

Submitted to the Faculty of Architectural Lighting Design I Department of Architecture, in fulfilment of the requirements for the Degree of

Master of Architectural Lighting Design, M.A.

At University of Wismar, Germany June 19, 2006

©Alfredo Garcia & Gaurav Jain, All Rights Reserved

Authors

Alfredo Garcia - 105552 Architectural Lighting Design Gaurav Jain - 106249 Certified by

Professor-Dr. Thomas Römhild Professor of Lighting Design HSW, Germany Thesis Guide Certified by

Professor Jan Ejhed Professor of Lighting Design KTH, Sweden Thesis Guide Certified by

Professor Hannsjörg Ahrens Professor für Baurecht und Baubetrieb HSW, Germany Thesis Guide

The authors hereby grant HSW permission to reproduce and distribute publicly, paper and electronic copies of this thesis in whole or part.

' ClaroOscuro lighting design


THESIS COMMITTEE Thesis Guides Prof.-Dr. Thomas Römhild

Faculty of Architectural Lighting Design Department of Architecture, University of Wismar, Germany Prof. Jan Ejhed Faculty of Architecture Lighting Design Department of Architecture, K.T.H., Sweden Prof. Hannsjörg Ahrens Faculty of Architecture Department of Architecture, University of Wismar, Germany

Thesis Readers Prof.-Dr. Thomas Römhild Faculty of Architectural Lighting Design Department of Architecture, University of Wismar, Germany Prof. Jan Ejhed Faculty of Architecture Lighting Design Department of Architecture, K.T.H., Sweden Prof. Hannsjörg Ahrens Faculty of Architecture Department of Architecture, University of Wismar, Germany



ABSTRACT REPRESENTING LIGHT: taking hints from fine arts and

simulation to Lighting Design by Alfredo Garcia and Gaurav Jain

Hypothesis

The current Lighting Design Methodology is often non-

contextual or takes self-invented context to suit the lighting design. The focus of the thesis would be searching for the true tool of Light Representation by re-reading the art to take clues of lighting, context and composition. The Thesis would give a new approach to Lighting Design taking the hints from subtle and artistic representation of light from Art and finding the techniques used by the Artists while painting their masterpieces. At the same time it would discuss about the contemporary tools of representing light namely simulation techniques and how well they can represent light when fed with the correct data and parameters or how flawed are these representations when done in isolation. The focus of this thesis would be first to study the techniques, quality, colours and the way light has been used, transformed, directed to make great masterpieces. The study would involve finding and listing the techniques employed and invented in the past to present and represent the special quality of contrast, context and Luminance (example Chiaroscuro, Daylight, Skylight, colours and context). In parallel the contemporary techniques for the same would also be studied, mainly simulation software and why we are unable to achieve a similar quality when compared to the Art. The second part would deal with combining the two to produce a new methodology of Lighting Design having the subtlety and character of art and the correctness and control of the Simulation software. The final part would be the installation of the concepts and designs thus produced from the combination of the two.



ACKNOWLEDGEMENTS

We would like to thank Hochshule Wismar

for two enriching years of education and understanding of Architectural Lighting Design. It was the knowledge imparted at this institution that made it possible for us to embark on the topic of study and research in our Thesis. This Master thesis would not be in the form today without guidance and direction from our thesis advisors and guides Prof.-Dr. Thomas Römhild (Hochshule Wismar, Germany), Prof. Jan Ejhed (KTH Syd, Sweden) and Prof. Hannsjörg Ahrens (Hochshule Wismar, Germany). Your criticism and comments really helped us in improving our work. Our sincere gratitude to you all of you. Our gratitude to Prof. Heinrich Kramer for his invaluable criticism and suggestions at the beginning of our thesis. Thanks to World Wide Web (internet) for the wealth of information available on it. We also wish to thank numerous departments / people / organisations that generously provided us with invaluable source of information, drawings and data. Unless otherwise mentioned, all views and conclusions in this thesis are our own. Personal Acknowledgements Many people were involved directly and indirectly with this project. To all of them, Thanks a big, big, lot. But specially I like to thank : My parents, Alfredo Garcia Romero and my mother Alice Mejia de Garcia, the persons who helped me to make this dream a reality. Julia Erlhöfer, somebody who supported and inspired me during this important period of my life. To Gaurav Jain, a friend who really knows what the life is for and helped me to understand it better. All my classmates in Wismar. More than classmate, friends for ever.

Alfredo Garcia

Personal Acknowledgements I would like to thank Alfredo Garcia my thesis partner for making this thesis a possibility. It was an excellent experience to work, discuss and carry out various experiments with him. I hope to further carry research on the topic with him and add to body of work done by us already. My special thanks to Chih-Chieh Hwang for introducing me to Lightscape for the first time, to Ya-Hui Cheng for her support and suggestions during my time in Stockholm, working on thesis. I thank my class mates in Wismar and Stockholm for their help, support and encouragement for the two years of Masters Degree. My sincere thanks to my parents for making this education possible for me.

Gaurav Jain



CONTENTS

PART A

A 1 Introduction — the necessity of human to represent the world

1.1 Images and Symbol Theory …02 1.2 Cultural Influence in the world representation …02 1.3 Art: Development of an Expression …04

A 2 Context — a world in Scale

2.1 What is context in Art …08 2.2 Harmony and Composition: giving order to the context …09 2.3 Light – Evolution of a technique …11

A 3 The Case Studies

3.1 The Paintings and their histories …15 3.2 L’empire des Lumieres (Empire of light), René Magritte …16

3.3 A Man seated reading at a Table in a Lofty Room …17

Follower of Rembrandt 3.4 The Bookworm – Carl Spitzweg …18

A 4 Conclusions and Guidelines …19



CONTENTS

PART B

B 1 Introduction — on Lighting in Computers

1.1 Background Context …23 1.2 Lighting in Architecture …23 1.3 Lighting Software History, Evolution & Revolution …24 1.4 Assumptions for study …27

B 2 Computer simulation of Lighting 2.1 Theory …29 2.2 The Purpose …34 2.3 Model Building …35

B 3 Ltighting Softaware - a Study 3.1 Overview …38 3.2 Feature Comparison & Ease of Use …39 3.3 Conclusions of the Study …42

B 4 Photometry-reading and writing it …43

B 5 Skies as Light Sources …46

B 6 Contrast and Colour …49

B 7 Conclusions and Guidelines …52



CONTENTS

PART C

C 1 LBR — The Luminance Brightness Rating System 1.1 Short Reference on Colour Theory …57 1.2 LBR – The grey scale for light designers …58

C 2 Re-reading the paintings and H.D.R.I. …60

C 3 Experiments and Analysis …64 3.1 Experiment 1 …67 3.2 Experiment 2 …68 3.3 Experiment 3 …70 3.4 Experiment 4 …74

C 4 Bringing together — The design and installation …76 4.1 Analysis of existing site conditions – Luminance and Points of Focus …78 4.2 Design Concepts, Sketches and contrast Analysis (LBR) …79 4.3 Computer Simulation and Luminance Analysis (Lightscape) …82 4.4 Design Installation and Analysis (HRDI and Radiance) …86

C 5 Comparison & Final Conclusion …88



CONTENTS

PART D

D 1 References …92



Part A

Thesis

Introduction

1



INTRODUCTION - The necessity of the Human to represent the World

1.1 Images and symbols theory The visual process is a combination of many different actions in addition to the simple fact for us to see. It is the way to understand the external world through a system of images and symbols created by the human being and his society along the history; a system that we learn to represent during the first years of our lives and with the time we improve by adding new symbols and images. All that we see was given a name and we only understand the world through these names. But why we call a tree, tree and not house? Who gave this relation between the image of a tree and its symbol? And going deeper, why do we make the relation between what we understand with the image of a tree and the joint of this idea with this other symbols “T – R – E – E”? (Figure 1a, b, c) In theory we can say that the world is a complex “box” of images and ideas organized in many different ways, and how we understand the world is our personal way to organize this “box”. In conclusion, all is just about association. All the elements that we know in the world are known as they are just because an unconscious and spontaneous connexion between simple ideas and complex ideas. All this associations are directly connected with the imagination, place where the reason can’t play any roll. Continue with this philosophic topic about association of ideas developed by David Hume, philosopher of the XVII century, will pick us out of focus from our main thesis theme. We just want to mention to open your eyes and try to make you think about the importance of understanding well the simple ideas in order to improve the develop of complex ideas. 1.2 Cultural influence in the World representation. We introduce you the `context´. The learning process of images association and interpretation is different between the different humans and like we explained it the last chapter, a complex idea is a group of simple ideas. Let’s take a look again to the idea of the tree: If we asked you to draw a tree, the way to interpreted it will be different between all of us and it is something about how your brain learned to interpret the external world. And this way to interpret the world is always influenced by the culture in which you grow up. The meanings, ideas and concepts are learned in a context that could be more and less the same between the people with the same culture.

Figure 1

Figure 1a

Figure 1b

2




Context is all that surrounds us, natural, artificial, biological, psychological, physiological and cultural that affects our lives. How we perceive the world, how we understand its changes, the animals we take like pets or the colours we use to wear or paint our houses. This context is given through the years by observation and is communicated between generations from parents to children. We were born with a context, we live in a context and we die in a context. It is impossible to imagine something without a context. In other words, to conceive a concept of no context doesn’t exist. At this point we can make a differentiation between two concepts that in a certain way are the same concept but they happen in different period time: Context and Background. Before going further, please take a look to the figure No.3. From the dictionary, this is the signification of context :

con·text Listen: [ k n t kst ]

n. 1. The part of a text or statement that surrounds a particular word

or passage and determines its meaning.

2. The circumstances in which an event occurs; a setting.

[Middle English, composition, from Latin contextus, from past

participle of contexere, to join together : com-, com- + texere,

to weave; see teks- in Indo-European roots.]

And this the signification of background :

back·ground Listen: [ b k ground ]

n. 1. The ground or scenery located behind something. 2. a. The part of a pictorial representation that appears to be in the distance and that provides relief for the principal objects in the foreground. b. The general scene or surface against which designs, patterns, or figures are represented or viewed. 3. A position or area of relative inconspicuousness or unimportance. 4. The circumstances and events surrounding or leading up to an event or occurrence. 5. A person's experience, training, and education: Her background in the arts is impressive. 6. Subdued music played especially as an accompaniment to dialogue in a dramatic performance. 7. a. Sound that intrudes on or interferes with an audio recording. b. Low-level radiation, as from radioactive decay, that exists as part of the natural environment.

Figure 3 Context and background theory

3




Background is the entire context that comes into our lives till the last second before now. All that you learned, studied, saw, experienced and lived. All the events affect us now, our present, and also our future. The way you will understand the thinks and communicate with the others, the way you will confront the life and interchange experiences, in summary, how we socialize and develop our personality is based on our background. Now we have more than the simple tree. We need to think about a group of trees: a forest. How can we imagine a forest now? (Figure No.4a) Unconsciously we remember the simple idea of tree, than the meaning of forest: a group of trees. We represent this idea in the way that we learned to associate it, and always influenced by a context till the last second before now, our background . Only knowing about our background is possible to understand that the meaning of tree, the simple idea could be the same association for everybody but the interpretation of a group of trees, a complex idea, never will be the same. So is possible to find a long chain of other different examples and interpretations influenced by local conditions, experiences and stories.

The idea in this chapter was to show you the importance of the context in our lives. All that we are is because of our context or past context, background and also if we talk about art, is necessary to think about context and the previous context of the artist context (background). Than we can go further and think about how important is the context of a painting, that “physical context” limited by a simple frame. Both are correlated, but for our purpose, the “second meaning” of context showed in a painting can give us hints to improve our way to realized lighting design. 1.3 Art: Development of an expression “Not what man knows but what man feels, concerns art. All else is science.” Bernard Berenson, 1897 First of all it is important to understand the meaning of art, what art is and what we understand about art. To confine this concept it is important to reference the previous chapter where we talked about images and symbols and how its understanding is affected by a cultural background and a context. It is also important to point how the human body feels the necessity to show others what it has learned, seen and experimented, show its ideas and emotions in a way that endure in time and pass over frontiers.

Figure 4a

Figure 4b

4




The human mind found the best way to express the world in a pictorial language, one derived from the direct seeing process, ART. The other one is a combination of language, expressions and symbols that represents the meaning of those images, LITERATURE . In our process of communication, both expressions have the same importance, but related to light, our topic in this moment, we need to focus our research in the direction of visual art. Since art is the expression made to represent the world, as a representation of the reality, is always influenced by many cultural, physical, psychological and sentimental factors. In other words, it describes the personal context of the artist at the moment when he decides to start drawing or painting.

If we take a look into the art history, we can recognize a change between the different centuries. It is possible to express it as a “development” in the way to express a painting. But this development shows us the evolution of humanity and it’s directly relation with the perception and later representation of the world. Technical advances and new discoveries are reflected in art expressions and through the years the ideal is always the same: represent with more and more fidelity in the world and its phenomenon. Topics about proportion, composition, perspective light and shadow have been in constant evolution. But talking about light, our thesis subject, the way to represent light could be compared with the evolution in the light control. At the beginning was just the use of daylight, then, the domination of the fire and at the end in our days the possibility to manage its intensity, brightness, colour and light shape. Now we have more tools to observe the relevance of the context in the visual art creations. But as we can see on the figure 5, in the process to understand paintings are different situations involved: The context and the time when the painting was done plus the influence by the context of the painter in his life (background). The context and the time when the painting is shown plus the influence by the context of the viewer in his life (background). This is a normal understanding process from a visual art representation.

Figure 5 - Backgrounds in relationship with a piece of art

5




But all has changed. The Renaissance and the Baroque painters exalted one day because their virtuosity representing the reality, lost importance with the development of the photography. In the figure No. 5 you will have a quick view of the different techniques developed by Bruneleschi and DaVinci with the lineal perspective, the use of some optic resources that helped the artist to paint a closer reality knowing it’s dimensions and proportions like we can see in Dürer´s lens, or the Camera Obscure, first step of the contemporary Photography.

All new discoveries and techniques helped the development of the visual representation and every representation technique bequeaths the humanity important theories. All this old theories are different landmarks in the history that allow the humanity to continue with the evolution. Is important to look backward in order to understand better the entire phenomenon and in this way make better proposals with the new discoveries and techniques. (Table 1)

In our case, we need to understand deeper the context of our projects and know better the new technical tools. In other words, it is possible to make an analogy with the old painters: composing paintings with light but improving our “light pieces” with the new scientific discoveries.

Table 1

Figure 6 - Cave paintings Figure 7 - The Calling of St Matthew Figure 8- very first photograph to be taken on glass by Jhon Herschel

Century XIV Some painters of the centuries1301 to 1400

Pre-renaissance di Bondone

Treccento von Tübingen

Century XV1401 to 1500

Early renaissance Rafael van Eyck

Quatroccento Boticcelli Fouquet

Fray Angelico Giorgione

Century XVI1501 to 1600

Renaissance Da Vinci Pontorno

Cinqueccento Boticcelli Giambologna

Manierismo Michelangelo Rosso Fiorentino

Caravaggio

Tintoretto

Tiziano

Century XVII1601 to 1700

Baroque Canaletto Rubens

Chiaroscuro Velazquez Rembrandt

Tenebrism Zurbaran de la Tour

Rivera Vermeer

El Greco Wright of Derby

Century XVIII1701 to 1800

Rationalism

Illustration

Century XIX1801 to 1900

Neoclassicism Goya Blake

Romanticism Pissarro Martin

Impressionism Spitzweg Turner

Century XX1901 to 2000

Expressionism Monet Gauguin

Peter Hurd Munch

Van Gogh

Surrealism Rene Magritte Picasso

Dali Garcia Lorca

6



Context

A world in scale

7



CONTEXT - a World in scale

2.1 What is context in art?

“ We never recognize a piece of art because its content, but because its context.” Dani Cavallaro In the first chapter we talked about context in general, how it affects our perception of the world and how it influences our way to represent the world. Now, in this second chapter we will explain how the observation of a painting bears a high visual experience that combined historical, emotional, cultural, psychological and physical facts. A play of interpretations between the painter and the observer is limited by frames. In the figure No. 5 we tried to explain the complex connection of contexts and backgrounds of the painter and the viewer in a canvas. But if we go deeper, the frame, this “physical limits” of a painting enclose a small part of what the painter is viewing or imagining. This is just a small piece of reality or in other words, the reality that the painter wants to show us. Just changing the size of the frame can give the author the possibility to tell different stories from the same reality. (Figure 9, 10, 11)

To understand a piece of art is necessary to take a look in each detail that composes it. Many symbols, languages, forms and ideas can be interpreted in different ways, but the most we study the painting the most we understand the author and his ideas, his culture his feelings and of course his background and context. So, context is not just the topic of a painting, is the interaction of many graphical, technical and compositional elements that helps the author to enhance the expression of an idea. The different methods to combine all these elements create a particular piece of art. But if they are combined in an erudite way could be possible that you are in front of a master piece. The idea is not going deeper into this subject of what do we understand as a master piece or when a visual art representation receives this title, rather we want to emphasize the idea that everybody knows sub-consciously when something is harmonic or not, or when something is disproportionate or not. In few words there is a “thin line” that arranges all the art representations that we understand and know like master pieces, because in our subconscious we always prefer to see the “beautiful” things than the “ugly” ones.

Figure 9 Figure 10 Figure 11 A complete painting and two detail in order to explain how the variation of the frames change completely the context of a painting.

Figure 9

Figure10

8




The concept can change between different persons because the context and the background, but the idea will be the same everywhere. Please try to remember in the first chapter the idea of the tree and the different representation but the same meaning.

To look is a private experience; We understand the things in terms of keenness and personal feelings.

2.2 Harmony and composition. Giving order to the context Sometimes we identify images that we like more than others or the ones we prefer better than others Why? All the thoughts expressed in the firsts chapters help us to outline a theory based on the idea that different people’s perception of things are connected with a “thin line” of what they understand from “beauty” or “ugly” and is directly related with the idea of the world and its natural order and organization. What does it mean? The nature has its own hierarchy and order . And we understand the world with this hierarchy and order. If we change something in our representation of this world, it will be difficult to understand for our brain. With the image of the tree again. The tree has a thick trunk at the base and small branches at the top.

(figure 12) If you draw a tree with a thin trunk and thick branches? What do you feel? (figure 13) And going further with the same idea, from the figures in graphic 9 which of them do you feel more stable? Table 2

There is always a harmony , a natural harmony that the human always try to reply. This harmony is understood as a general context in which perspective; colour, brightness and contrast are given naturally in our perception of things. But if we add some frames, the context changes, like we explained in the last chapter. And if we “manipulate” the composition inside these frames, will be possible to enhance parts of a painting in order to express a concept.

Figure 12

Figure 13

9




In order to catch the viewer’s attention, many “tricks” are used to manipulate the world into the frames. Rhythms, hierarchy, lines, axes, forms position, forms interaction, etc. are just small elements used for this purpose. And in order to express these elements, some techniques like perspective, colour and light are used. (Table 2) In conclusion to this chapter, the nature gives us guidelines about harmony that we can interpret and use in order to represent and compose our “limited context”. It means we can give order to this context by “manipulating” some techniques that will enhance the harmony and composition of a painting.

Is important to talk about another element that indirectly is contained in all the other art composition tools, and is the way that the eye recognizes elements at the moment it scans the environment and is called focal accent . Lou Michel, in his book “Light: The Shape of space explains in detail his theory of focal accent . He explains how this high perceptual stimuli is felt at the moment our eye scans a particular space and how it could be organized into different hierarchies. These are: 1. People 2. Movement 3. Brightness 4. High Contrast 5. Vivid Colours 6. Strong Pattern

“Beautiful is something that the sight enjoys … because everything is clearer and more beautiful if observed with the eyes than described in words.”

Thomas of Aquino

Table 3 y 4

Elements of Art Color

Form

Line

Shape

Space

Texture

Value

Principles of ArtBalance

Contrast

Emphasis

Proportion

Pattern

Rhythm

Unity

Variety

10




2.3 Light – Evolution of a technique To talk about technical resources of the table 2, is a discussion about the different discoveries done by the humans after years of research and study. It is topic about world and its natural phenomenon that the humans analyzed in order to learn and develop an accurate representation of the world in the paintings based on those discoveries. Now, the meaning has changed. Now the visual arts have another direction. The interest to represent a reality does not have the same meaning. The development of photography and the use of computers helped to catch an instant with an incredible exactitude. But at the same time, some feelings and sensations are impossible to represent or to interpret. If we take a retrospective vision of visual art representation we can distinguish how and when the incidence of light began to have an important part in the paintings. The prehistoric art, the ancient art, (Egyptian and Mesopotamian), the classic art in Greece or Rome where the proportion began to play an important roll, the middle age (XIII century, 900 to1300 and part of the XIV), are centuries were the perception of light was a theme used in a very superficial way. Its use was completely related to the basic perceptions and its employment in a painting was completely irrelevant.

In the second part of the XIV century (Pre-renaissance, treccento) the use of light and shadows were still unexplored topic, but it is possible to recognize an empirical use of it. The XV century (1401 to 1500) is recognized as the beginning of the renaissance (Pre- renaissance or Quatroccento). Painters like Rafael, Botticceli or Fray Angelico between others began to study the perception of light and shadows and used it consciously in paintings. But was in the apogee of the Renaissance where the painters really begun to take care of the optic, light and colour. Geniuses like Leonardo da Vinci, Bruneleschi or Botticcelli studied in detail this entire natural phenomenon in order to improve the representation of the world.

Movements like Mannerism in this century used the light as on of the main composition elements. But was in the XVII century (1601 to 1700) the Baroque, were the study of light and corresponding phenomenon, arrive the zenith epoch of light representation and the use

Figure 14 - Principle of the line perspective .

Figura 15 - Dürer’s perspective technic .

Figure 16 - Camera Obscura technic

11




of technical aids in order to generate a more accurate representation of the world. Continuous depth using foreshortenings, darkness, play of light, atmospheric effects. Light hegemony. No more esfumato from the renaissance. Colours were very contrasted because the use of them marked shadows. The form in subordination to the light is the main used concept in this part of the art history and is really enhanced in the chiaroscuro and tenebrism movements. Some representatives like Miguel Angel, Boticceli, and Caravaggio in the XVI century, followed by Canaletto, Velazquez and Rubens at the beginning of the Baroque century lit small elements to attract the attention of the viewer. Zurbaran, el Greco, Rivera in Spain; Rembrandt de la Tour, Vermeer in the north are some other examples of painters that used this technique to compose their paintings. The early renaissance in the XV Century (1401 to 1500) was the time in which the use of perspective and shadows had a meaning in the composition. Bruneleschi and Leonardo da Vinci in the XVI Century (1501 – 1600) time of the renascence’s apogee, made deep studies to understand the human sight. The distortion caused because of the form of the eye and the close result found in the rational and mathematical representation of the linear perspective is just one of the natural phenomena translated into numbers.

After some centuries, based on the idea of the “Camera Obscura” imagined by scientifics like Girolamo Cardamo or Leonardo da Vinci in the XVI century and later used by many painters as an aid to drawing, the Photography as we know it now was developed by Sir John Herschel in 1839. At that time some artists saw in photography a threat to their livelihood, and some even prophesied that painting would cease to exist. In the XIX century the Impressionism began to be a strong movement between the artists. The interest in showing the things like they are but giving a bigger importance to the human sensations was the fundamental aim. The reality is represented with colour patches. The boundaries do not exist. The shadows are not black, the light is not white. Everything is a mix of less or more saturated colours.

It is also a play of composition and harmony, a “manipulation”, but made with colours. We can mention Monet, van Gogh or Munch like some of the best representatives.

Figure 17 - Cave paintings Figure 18 - Egyptian Painting

Figure 19 - Byzantine and Roman epoch Figure 20 - David Gerard - The Virgin and Child with Saints and Donor Figure 21 - Leonardo da Vinci – The last Supper

12




Figure 22 Caravaggio – Supper at Emaus Figure 23 Grimshaw - Liverpool from Wapping

Figure 24 Monet - Impression: Soleil Levant

Figure 25 - Ury - Elevated Railway Station at Bülowstrasse Fig. 26 Hooper-Nighthawks

13



The Case Studies 14



The Case Study

3.1 The paintings and their histories

I. Painting : L’empire des Lumieres (Empire of light) Figure 27

Author : Rene Magritte Year : 1953–54 Technique : Oil on canvas Dimension : 195.4 x 131.2 cm Style : Surrealism

II. Painting : A Man seated reading at a Table in a

Lofty Room. Figure 28 Author : follower of Rembrandt Year : about 1628 - 30 Technique : Oil on oak Dimension : 55.1 x 46.5 cm Style : Baroque – Tenebrism

III. Painting : The Bookworm Author : Carl Spitzweg Figure 29 Year : about 1628 - 30 Technique : Oil on canvas Dimension : 79 x 50 cm Style : Later romanticism

Figure 27 Figure 28 Figure 29

15



The Case Study

3.2 L’empire des Lumieres (Empire of light) Rene Magritte Surrealism: Artistic, cultural and intellectual movement oriented toward the liberation of the mind by emphasizing the critical and imaginative faculties of the "unconscious mind" and the attainment of a state different from, "more than", and ultimately "truer" than everyday reality: the "sur-real" , or "more than real" . Analysis: Worked with a lot of technique, In “L’empire des Lumieres” we can recognize the juxtaposition of ordinary objects and unusual context, giving new meanings to familiar things very common in his paintings. Here, an incredible blue sky with clouds and a typical sunlight present normally near to the afternoon in opposition to the extremely darkness inside the forest and the lights switched on. If you take a quick overview to the painting, and we asked you what was the first think that you saw on the painting, could be possible that your answer will be: The Lantern. Why? Because the composition. (Figure 30) The first look you could find an annoying painting because the juxtaposition of day and night, but the harmony used on it is incredible. The simple centre linear perspective used on it where the vanishing point is located slightly shift to the right helps to guide the viewer sight into the zone where the lantern is. (Figure 30) So the composition of the dark and bright parts of the painting helps to guide the viewer sight to the lantern zone increasing the tension in that part of the painting. The experiment of converting the painting in black and white helps us to understand better how the use of extreme contrasts helps to compose and guide the eye. (Figure 31) Particularly in this painting it is interesting to observe the balance existing between black and white. In the image No. 32 we present a painting converted in 3 colours, dark parts in black, light parts in white and a middle point represented whit grey that show us the transition points in the painting. Here we can see how the painting divides itself into layers pushing the brighter on to the bottom of the composition. Analyzing the grey tones, we can say that in most of the times is used like a transition

Figura 30 – Perspective study

Figure 31 – Composition study through contrast

Figure 32 – Composition study through Brightness

16



The Case Study

between the high and low contrast used to soften the transition. As mention in the last chapter, the hierarchy of focal accent in this painting is oriented into the area in which the brightness and height contrast is enhanced. Could be that the sky is as bright as the lantern, but the height contrasts used in the lantern area and also the axis formed between other high contrast elements in the painting helps this orientation of the eye into that point.

3.3 A Man seated reading at a Table in a Lofty Room Follower of Rembrandt

Baroque - Tenebrism: From the Italian tenebroso ("murky"), (also called dramatic illumination) is a style of painting using violent contrasts of light and dark. It is a heightened form of chiaroscuro. It creates the look of figures emerging from the dark. It also differs from chiaroscuro in that it contains a defined source of light.

Analysis: Until recently attributed to Rembrandt, this work is now thought to be a work of an early, perhaps contemporary, follower of Rembrandt. The artist has imitated the style of Rembrandt's early years (1625-31) when he worked in his native Leiden, a style characterized by the precise treatment of detail and strong contrasts between light and dark. This picture was probably painted in Leiden in the late 1620s. The unusual perspective of this painting coming from below, near the ground, is something to emphasize. In conjunction with the use of sunlight and how it reflects on the back wall gives the viewer another point of view of the room. The use of dark and bright parts in order to create an atmosphere without enhancing a particular element is another point to have in mind and is because the century the painting is done. The technique used in this century was to guide the viewer attention and focalize it on the elements with lighted. (Figure 33) Here the technique is completely different; with the play of contrast the author enhance indirectly the presence of a person seated at the end of the room. Contrary as we can thing, the use of contrast in this painting is a second element of enhancing and guiding the view. Bright elements call your attention but mainly the eye point directly to the human figure in shadows. (Figure 34)

Figura 33 – Perspective study Figure 34 – Composition study through contrast Figure 35 – Composition study through Brightness

17



The Case Study

The lit background that creates a high contrast between the surrounding and the figure helps to achieve this effect. Why? It’s because what we talk about in chapter No. 3, that the human vision generally responds to focal accents being the people the first element. 3.4 The Bookworm

Carl Spitzweg Romanticism: Artistic and intellectual movement that originated in the late 18th century and stressed strong emotion, imagination, freedom from classical correctness in art forms, and rebellion against social conventions. Romanticism can be seen as a rejection of the precepts of order, calm, harmony, balance, idealization, and rationality that typified Classicism in general and late 18th-century Neoclassicism in particular. It was also to some extent a reaction against the Enlightenment and against 18th-century rationalism and physical materialism in general. Romanticism emphasized the individual, the subjective, the irrational, the imaginative, the personal, the spontaneous, the emotional, the visionary, and the transcendental.

Analysis: Spitzweg’s closeness to reality, deception and folly, the ideal and the clearly coarse, mark the beginning of a new period that occupies the painter. He practices a kind of "romantic realism", and his which pictures are inspired by the great melancholic. In this painting we can see how the perspective in his composition is just a representation of the reality. There is no additional meaning of the perspective. It represents the reality like it is. The same with the different elements of the painting, all of them are very well proportioned giving the impression of a realistic painting. The calm perspective and the balance composition lets the Artist play with other compositional elements as light and shadows. (Figura 36) About the light in the painting, is also interesting the way that he use it in order to compose the painting. The ray of light coming from the top of the painting is used as a strong conceptual and compositional element. The contrast is used to highlight the activity of the character in the composition is important in our analysis. The way the painter plays with the contras having some lighted elements on the background and some dark foregrounds to enhance the foregrounds and in some parts how the foregrounds become light to enhance the activity of the character. (Figure 38)

Figura 36 – Perspective study Figura 37 – Composition study through contrast Figure 38 – Composition study through Brightness

18



Conclusions

Guidelines19



Conclusions and Guidelines

Symbolism Part Every expression has feelings inside. Everything that one thing, everything that one feel, talk, see, smell and hear has a deep meaning, a spirit that represent the author. In a way, the simplest movement, if well analyzed, can show the sensation and thought of the author in that precise moment. Developing a lighting design project is important to study very deeply the meaning of many elements in order to realize a design according to the necessities and impressions of the people that are going to enjoy the project. Analyze the use of the building and the spirit of the place. All the constitutive elements, geometries, shapes and axis in order to propose something that will give that place the meaning that the night hides. Is to enhance its best elements and guide the people sights to its beautifulness profile modelling with respect al its contours. Understand every each simple idea to interpret the whole concept and understand it in terms of shadows, light, darkness and brightness. A lighting design project must be deeply studied and analyzed in order to understand the context that surrounds it and in which it will cohabit friendly with the world. Composition A painter represented a 3d world in a piece of canvas in order to express his deeper feelings. He studied during many years the nature of the things, its structure and order, its logic to achieve better the representation of the idea he wants to express. But painting his canvas he saw that is possible to reorder and restructure his representation and in this way enhance the idea or feeling in that moment. In our times the techniques are given. One need to find them, understand them and use them. Take advantage of all our predecessors’ studies to achieve the best possibility to represent the world and our feelings. Take a look with an open mind and having the enough sensibility to reinterpreted their works in order to know what and how can we use it in our times. In our case, we are taking advantage from all the studies done before for 2d visual art representations and reinterpreted it in a way that orient our way to improve our lighting design projects.

Figure 39 – The tree

Figure 40 – Gaurav’s tree

Figure 41 – Alfredo’s tree

Ballade von der Lichmalerei

Robert Gernhard

20



Conclusions and Guidelines

How we can use the real light, the real perspective and the real axis in order to make our contemporary 3d composition. Now we need to understand well the deeper structure of light and only we, the architectural lighting designer, are capable to understand and combine with erudition: - the high technology that represents handling the light, - the meaning and spirit of a space and read in it its potential - The structure and function of the parts of a building. Grey Part We studied the simple elements and its combination, we studied the history and the theory in order to develop a concept. Now we need to study the technique in order to achieve more precisely the execution of the project. To develop better the concept of the project is necessary to divide it in simple parts in order to understand better the whole complex. An also it works with our technique. The world in colours is beautiful to contemplate, but at the moment to study is difficult and complex. Therefore is necessary to take out the colour and work just with basic elements of the light phenomena: Brightness and darkness

“The separation of light and dark from all appearance of colour is possible and necessary. The artist will solve the mystery of imitation sooner by first considering light and dark independently of colour, and making himself acquainted with it in its whole extent”

Goethe

Figure 42 – The inspiration and concept

Figure 43 – The Techniques

21



Part B

Thesis

Introduction

22



INTRODUCTION – on Lighting in Computers

1.1 Background Context By day building has light and shade, by night all this recedes into the dull monotony of consistent blandness and invariant illuminance. This can be said assuming that there is no electric or any other man-made source of light in the context. The shift from the human need from a cave shelter to more complex, facilitated and expressive form of building opens doors to many discussions. Both Daylight and Artificial Light have played a major role. Both of these have their own aesthetic qualities. Thus both of them should be complimentary to each other than in conflict. The prime aim should be to integrate the two than one negating the other, both in day time and night time situation. Often one notices the subtlety of moonlight and stars and the night skylight. This is mostly possible in absence of electric lighting in the near vicinity. `Ìn the perception of an object in an obvious illuminant such as sunlight or a lamp, variations in intensity caused by the shape of a surface are perceived directly as shape and not intensity changes. In fact this perception is usually so strong that’s it is almost impossible for the untrained observer to see the `shading´ of objects at all. Yet it is this shading that the artist must see or the competent photographer (or lighting designers in our case) must reproduce in consciousness if he is to produce the perception of shape in mind of the person observing his reproduction.´´ (Evans, 1948) The aim of this study is not to run light calculations and find results, rather to find the best way of translating the Light from the conscious to paper and then to reality, while doing we need also to quantify the colour, contrast, light level, direction and method (the software would serve as quantifying the parameters). But the difference this time is to produce the artistic quality through hints and techniques from the paintings. Designers and researchers have been calculating and trying to show the effect of Lighting since centuries much before the use of computer technologies.

1.2 Lighting in Architecture For many designers the use of light in design is an artistic skill that cannot be expressed by a set of design standards or mathematical formulae. These designers are able to use or craft the designs with light in much the similar way as the painter uses paint and the musician composes music. In contrary to the above there are designers who need help and guidance for the development of their Lighting design schemes. This can be in terms of both visual appearance

Aguilon's photometric experiment of 1613

23




and quantitative aspect of Lighting. For which it is not always possible to fall on the empirical method of design. To this end there have been several developments in the complete science of lighting that provides a description of the physical properties of light and the objects that reflect, absorb and transmit light. From these developments and formal research we now have a wide range of design tools that allow designers to meet the requirements of design (levels of Luminance and Illuminance, avoidance of Glare, control over daylight and sun penetration etc.) The physics of light is both complex and fascinating and there are few who have been able to use and apply it successfully and artistically in design, art and architecture. The advent of Lighting Software and technology made it much easier to understand the characteristic and know quantitatively and visually the effect of certain lighting. 1.3 Lighting Software History, Evolution & Revolution Many formulae and concepts used by the lighting design software have been around since the late 1800´s. But it was only in the last few decades; particularly the 80´s and 90´s that one sees an exponential growth in computer related lighting design developments. In mid 1900´s a paper was presented which influenced and had a major impact on the capability of current Lighting Design software. It was based on “Inter-reflection” method of calculation to predict the brightness and brightness ratios in the interior environments. Prior to these study methods of predicting surface illumination that took into account reflected light were unavailable to lighting designers. They normally used an integration formula which considered inter-reflected light in rooms of any shape; they calculated five different lighting conditions – indirect, direct, light troughs, diffusing globes and semi-direct illumination. These results were used to simulate “synthetic image” perspective views created from pieces cut-out from Munsell paper ironed together, each colour corresponding to a specific reflectance value. (Refer to Figure-1 and Table-1 ) This research led in establishing in a 3-to-1 line-of-sight criterion for illuminating the interior spaces used today. At that point time stress was laid on the importance of the brightness calculation and its predetermination would be of utmost importance to the Lighting Designer or engineer. This became reality when four decades later the same synthetic image was produced not manually but rendered from a Lighting Design Software. Early software applications for lighting calculations were not readily available to the public but were created as a result of in-house needs. This was due to the fact that most companies could not afford in-house computers. Instead companies relied upon time-share systems where a user could pay for computational time and disk storage from

Figure 1

Table 1 Relation between Reflectance and Munsell Value

24




computers owned and maintained by outside sources. In the late ’60s and early ’70s, users of time-share systems would upload/download processes and data into a central queue over phone lines using a Teletype machine and punch tapes (Figure 2 ). Charges for using a time-share system depended on the amount of processing time needed to achieve the results, the amount of disk storage rented and the time of day and the duration that the connection took place. As a result of the high cost to use the system, designers needed to determine which applications were necessary to warrant the use of the computer calculations and which should be done manually.

Photometric testing laboratories became interested in lighting calculations as an additional courtesy service offered to customers. Since they were already providing CU values for luminaires, it was a “simple” step to take lighting calculation to the next level by offering foot-candle calculations. In 1968, a prominent lamp manufacturer developed a point-by-point software application called “LIGHT.” This software enabled the user to calculate a maximum grid of 100 points.

At the same time “LIGHT” was being used, David DiLaura developed “Lumen 1” as a program to help engineers predict the results of their lighting design through point-by-point calculations of a complete area. As with other applications, “Lumen 1” required the use of a time-share system to run the program. This software was not restricted by the quantity of calculation points but the memory capacity of the computers. Data input to the central computer over the Teletype system included the room’s dimensions, reflectances, locations of windows and locations of luminaires using X and Y Cartesian coordinate values. Photometric values of the luminaires were also used, but without the establishment of IES photometric files at that time, each value along the horizontal and vertical angles of the luminaire had to be input separately. If a value was input incorrectly, there was no checking system to indicate an error had been made. The designer relied upon his own lighting experience to determine if the results appeared accurate or not. Over the next three years, DiLaura further developed the program to predict a lighting design taking into account inter-reflected light of an empty room. In 1970, DiLaura joined Smith, Hinchman & Grylls (currently SmithGroup) and expanded his rudimentary program to calculate foot-candle levels, day lighting, disability/discomfort glare and the Visual Comfort Probability (VCP).This version became “Lumen 2.” James Benya, one of the first users at SmithGroup, helped develop a statistical analysis pre-processor for the program to make sure all the variables were there and made sense. In 1980, DiLaura moved to Boulder, CO, and founded Lighting Technologies with David Kambich. In 1981,

Figure 2

Table 2a-Light Lamps & Software

Figure3- 1985 Dot Matrix Simulation

25




Lighting Technologies presented “Lumen 3” to the public and made it available through Computer Sharing Services (CSS)—a nationwide timesharing system company headquartered in Denver. PCs Emerge In 1982, IBM produced the first “personal” computer called the microcomputer—similar to the PCs of today. Lighting Technologies decided to take a chance and gamble that engineers and companies would buy their own microcomputers instead of continuing with the time-share system. In 1983, the company released “Lumen Micro” version 1.0—the name change due to the recent development of the microcomputer. This version utilized the computer screen instead of teletype tape printouts but the data was entirely character-based. It wasn’t until 1985 that it developed the first graphical output for lighting calculation results—but this output was not generated on the screen. It was a shaded view produced on a dot matrix printer (Figure

3)—similar to the “synthetic images” created by Moon and Spencer four decades earlier. Around this time, others saw the opportunity to create lighting design software applications. In 1984, LAI released its first general point-by-point program called “POINT” followed by an isoilluminance template program called “ISOPOINT” in 1985, and an interior lighting program called “INSIGHT” in 1989. This was followed by a DOS based release (AGI-DOS) in 1991 and a Windows based release (AGI32) in 1999. Photo-realistic Renderings In 1989, Greg Ward of the Lawrence Berkeley National Laboratory (LBNL) released Radiance, a UNIX-based ray tracing simulation that handles specular and diffuse inter-reflections (Figure 4 ). In 2000, LBNL released Desktop Radiance for the Windows platform, and today this package serves as the basis for over a dozen Windows-based lighting tools. In 2002, LBNL made Radiance open source, and an active community of users, researchers and developers continues to build upon this free software base. In 1991, Stuart Feldman, Rod Recker and Filippo Tampieri discussed developing a commercial product to produce photo-realistic renderings as an alternative to physical mock-ups for designers. They wanted to create a product that would be distinguished from other visualization software. They incorporated radiosity algorithms— and later .IES photometry for real physical lighting units—to create not just “a pretty picture” but something more meaningful to designers (Figure 5 and 6 ). Thus was born the original Lightscape Software and was developed on Silicon Graphics (SGI) machines. In 1996, when Microsoft developed Windows NT with OpenGL capabilities, the first version of Lightscape for personal computers emerged. This Windows version appealed to more people since it was naturally easier to use than the

Table-2b-Light Lamps & Software

Figure 4 – Radiance Simulation

26




SGI based version. In 1997, Lightscape Technologies was acquired by Discreet. Future Today, GUIs and processing speeds are changing more than actual lighting calculation algorithms. According to DiLaura, “The industry is satisfied with the current capabilities of lighting design software. As such, there is no economic reason to pursue near field photometry software capabilities. But without the demand for near-field photometry, visualizations will not be accurate.” In essence, lighting design software research has come to a halt past 10 years with no major developments in lighting calculation algorithms. 1.4 Assumptions for Study The study presented in this thesis has taken information form already published and researched material. Thus this thesis in many ways a compilation of topics which were required to come to a conclusion and design methodology that forms the basis of our study. The thesis does not delve in to all technical details about various techniques, algorithms, mathematics etc. in making those tools or packages. But the thesis sites references to all such topics where the reader can find further details on topic of interest. The interest of this report is not just to find the best software for light simulation. This has been long established in many studies and seminars. Rather we would use the possible computer tool (s) available to give a more artistic approach to the Lighting Design process which uses the Colour, Contrast, composition and context of the Masters of Fine Arts.

Figure 5- Lightscape Simulation

Table 2c- Light Lamps & Software

Figure 6 Lightscape Simulation

27



Computer Simulation

Of Lighting

28



COMPUTER SIMULATION of Lighting

2.1 Theory A 3D model contains geometric data defined in relationship to a 3D Cartesian coordinate system, sometimes referred to as world space. The model may also contain other information about the material of each of the objects and the lighting. The image on a computer monitor is made up of many illuminated dots, called pixels (Figure 7 ). The task in creating a computer graphics image of a geometric model is to determine the colour for each pixel on the screen (screen space) based on the model information and a specific viewpoint. The colour of any specific point on a surface in a model is a function of the physical material properties of that surface and the light that illuminates it. Two general shading algorithms, local illumination and global illumination are used to describe how surfaces reflect and transmit light. Local Illumination Local illumination algorithms describe only how individual surfaces reflect or transmit light. Given a description of light arriving at a surface, these mathematical algorithms predict the intensity, spectral character (colour), and distribution of the light leaving that surface. The next task is to determine where the light arriving at the surface originates. In a simple rendering algorithm, only the light coming directly from the light sources themselves is considered in the shading. For more accurate images, however, it is important to take into account not only the light sources themselves, but also how all the surfaces and objects in the environment interact with the light. For example, some surfaces block light, casting shadows on other surfaces; some surfaces are shiny, in which case we see in them the reflections of other surfaces; some surfaces are transparent, in which case we see other surfaces through them; and some surfaces reflect light onto others. Global Illumination Rendering algorithms that take into account the ways in which light is transferred between surfaces in the model are called global illumination algorithms. Both Ray Tracing and Radiosity are Global Illumination algorithms. Before an explanation how ray tracing and radiosity work, it is useful to understand how light is distributed in the physical world. Consider, for example, the simple room shown in Figure 8 . This room has one light source. One theory of light considers the light in terms of discrete particles called photons, which travel from the light source until they encounter some surface in the room. Depending on the surface material, some of these photons, travelling at particular wavelengths, are absorbed and others are scattered back out into the environment. The fact that photons travelling at a particular wavelength are absorbed

Figure 7 – Pixels – the illuminated dots

Figure 8 - Global Illumination in a Room

29




while others are not is what determines the colour (also referred to as the spectral reflectance) of the surface. The way in which the photons are reflected from a surface depends primarily on the smoothness of the surface. Rough surfaces tend to reflect photons in all directions. These are known as diffuse surfaces, and this type of reflection is known as diffuse reflection (Figure 9 ). A wall painted with flat paint is a good example of a diffuse surface. Surfaces that are very smooth reflect the photons in one direction, at an angle equal to the angle at which they arrive at the surface (angle of incidence). These surfaces are known as specular surfaces, and this type of reflection is known as specular reflection (Figure 9 ). A mirror is an example of a perfectly specular surface. Of course, many materials display some degree of both specular and diffuse reflection. The final illumination of the room is determined by the interaction between the surfaces and the billions of photons emitted from the light source. At any given point on a surface, it is possible that photons have arrived directly from the light source (direct illumination) or else indirectly through one or more bounces off other surfaces (indirect illumination). If you were standing in the room, a very small number of the photons in the room would enter your eye and stimulate the rods and cones of your retina. This stimulation would, in effect, form an image that is perceived by your brain (Figure 7). In computer graphics we replace the rods and cones of a retina with the pixels of the computer screen. One goal of a global illumination algorithm is to re-create, as accurately as possible, what you would see if you were standing in a real environment. A second goal is to accomplish this task as quickly as possible, ideally in real time (30 images per second). Currently, no single global illumination algorithm can accomplish both goals. Ray Tracing One of the first global illumination algorithms developed is known as ray tracing. The ray tracing algorithm recognizes that although billions of photons may be travelling about the room, the photons we primarily care about are the ones that enter the eye. The algorithm works by tracing rays backward, from each pixel on the screen into the 3D model. In this way, we compute only the information needed to construct the image. To create an image using ray tracing, the following procedure is performed for each pixel on the computer screen (Figure 10 ). The ray tracing algorithm is very versatile because of the large range of lighting effects it can model. It can accurately account for the global illumination characteristics of direct illumination, shadows, specular reflections (for example, mirrors), and refraction through transparent materials.

Figure 9 – Diffused and Specular Reflection

Figure 10a – RayTracing

30




The main disadvantage of ray tracing is that it can be computationally expensive and slow for environments of even moderate complexity. Another significant disadvantage of ray tracing is that it does not account for one very important characteristic of global illumination diffuse inter-reflections. With traditional ray tracing, only the light arriving directly from the light sources themselves is accurately accounted for. But, as shown in the room example, not only does light arrive at a surface from the light sources (direct lighting), it also arrives from other surfaces (indirect lighting). If we were to ray trace an image of the table, as shown in Figure 10 , the area under the table appears black because it receives no direct light from the light source. We know from experience, however, that this area would not be completely dark because of the light it would receive from the surrounding walls and floor. In traditional ray tracing this indirect illumination is usually accounted for simply by adding an arbitrary, ambient light, value that has no correlation to the physical phenomena of indirect illumination and is constant throughout space. For this reason, ray traced images often appear very flat, particularly renderings of architectural environments, which typically contain mostly diffuse surfaces. Forward raytracing - In this case, the program simulates rays of light (or other spectra) that emanate from a light source, and determines where they end up when following a number of reflections on scene surfaces. This method is normally used in the design of luminaire reflectors and other optical equipment. Backward Raytracing - Here the program starts with scene, and casts rays into different directions, until they hit a surface in the scene. At this point, it tries to find out what amount of light is available to illuminate this surface. This can happen with the help of an ambient term, which represents an (unrealistic) global brightness of the scene, by determining the distance to one or several light sources, or recursively by sending more rays into the scene from that point on. A combination of the last two methods, called distributed raytracing, is the most interesting one for our purposes. Distributed Raytracing - This is a very powerful approach for simulating the diffuse light distribution and reflection in three dimensional environments (a solution to the "global illumination model") and is used in the Radiance software. (Figure 10b) Distributed raytracing can simulate scenes of extreme complexity quite effectively, while for scenes with very high numbers of light sources the radiosity approach often has some advantages.

Also known as Monte Carlo Raytracing method

Figure 10b – Monte-Carlo Raytracing

Figure 11 – Radiosity

Figure 12 – Radiosity

31




Radiosity Radiosity is a finite element method that simulates the transfer of radiant flux between Lambertian surfaces. Originally proposed in 1926 as a calculation tool for architectural lighting design, radiosity methods have since been successfully applied to photorealistic image synthesis in computer graphics. To address some of the shortcomings of the ray tracing algorithm, researchers began investigating alternative techniques for calculating global illumination, drawing on thermal engineering research. In the early 1960s engineers developed methods for simulating the radiative heat transfer between surfaces to determine how their designs would perform in applications such as furnaces and engines. In the mid-1980s, computer graphics researchers began investigating the application of these techniques for simulating light propagation. Radiosity, as this technique is called in the computer graphics world, differs fundamentally from ray tracing. Rather than determining the colour for each pixel on a screen, radiosity calculates the intensity for discrete points in the environment. This is accomplished by first dividing the original surfaces into a mesh of smaller surfaces known as elements. The radiosity algorithm calculates the amount of light distributed from each mesh element to every other mesh element. The final radiosity values are stored for each element of the mesh (Figure 10). In early versions of the radiosity algorithm the distribution of light among mesh elements had to be completely calculated before any useful results could be displayed on the screen. Even though the result was view independent, the pre-processing took a considerable amount of time. In 1988 this pre-processing portion of the radiosity algorithm was reformulated. The new technique, called progressive refinement radiosity, displays immediate visual results that progressively improve in accuracy and visual quality. Radiosity methods allow the lighting designer to produce architectural visualizations that accurately represent how light behaves in a physical environment (Figure13a, b & c ). Because these methods are based on physical principles, they also enable the designer to prepare point-by-point illuminance distribution (isolux) plots, luminance distribution summaries, and statistical reports that accurately characterize the luminous environment. Radiosity methods therefore provide the basis for both visual communication with the client and reliable engineering calculations.

Figure 13a – Radiosity: Surface Meshes

Figure 13b

Figure 13c

32




Radiosity has proven to be a highly efficient algorithm for estimating the light distribution in the scene. Even with very coarse meshes the resulting illuminances show relatively little error. Moreover, if one renounces the ambition of producing realistic images, computation times can be reduced considerably. A comparison with Radiance - a ray-tracer that is regarded in the academic world as highly reliable - seems to corroborate the hypothesis that radiosity’s fundamental principles make it more efficient for approximating the way in which light is spread throughout a scene than its counterpart ray-tracing. The argument that only diffuse material properties can be simulated is obsolete and only applies to classical radiosity. In the implementation that was used for the tests discussed earlier, the calculation of form factors was avoided by means of a raycasting procedure, facilitating the inclusion of specular behaviour. 6 (References- Reports)

Recently, the term Progressive Radiosity and Monte Carlo have been misattributed and confused to be the same. Progressive radiosity is the further development on the Radiosity algorithm. During this process, the user would see a completely dark scene progress to a fully lit scene. To accommodate this sharp contrast in visual difference from beginning to end, the progressive refinement technique added something called the "ambient term". There is no such thing as ambient light in real life. Ambient light is something that was invented to accommodate the need for what appears to be a "global light" in real life. But in reality, ambient light doesn’t exist. Rather, light is always being reflected from surface to surface. Before the advent of radiosity, ambient light was the best thing available to the typical rendering architectures. It is safe to think of radiosity is a more accurate solution to ambient (global) light. This is why radiosity is considered a technique for "global illumination."

Both Monte Carlo and Radiosity Algorithms are the best existing Light Calculation Algorithms, which are to an extent have an access through number of software. Advantages / Disadvantages Radiosity: (Figure 13 a, b, c)

- Very realistic lighting for diffuse surfaces - Conceptually simple and easy to implement - Easy to optimise with 3D hardware - Slow - Does not handle point sources well - nor shiny surfaces - Always over complicated and poorly

explained in books

33




Monte Carlo Method: (Figure 10 b) - Very, very good results. - Can simulate pretty well any optical

phenomenon - Slow - Slightly difficult - Requires some cleverness to optimise - Always over complicated and poorly

explained in books

2.2 The Purpose

To translate the reproduction of light in the consciousness requires not just the skill to remember what makes jewellery sparkle or make objects look good, rather to follow the steps of an artist to create the lighting design concept in its true meaning. The ability involves bringing observation-based experience into the mental construct that is the design concept. Acquiring only the basic skills does not ensure us to have a ability to envision a Design Concept of Light. Thus to this purpose to come realistically close to the mental constructs or the images of Lighting Design or the urge to predict the Light Quality in advance. Predicting in advance would indeed lead to a better design and avoid the otherwise expensive mistakes that could have occurred. The two main goals of using computer simulations are to achieve:

• Realistic Visual Representation of the Lighting design to visualize the building and have an idea of how it will look in future.

• To produce a photometric model of the design which give the accurate estimation of lighting and quantities such as Glare, illuminance, luminance and daylight factor etc.

Also photorealistic models usually dominate most of the Computer Visualization work that is done. Often these images are quite realistic in appearance and the parameters to produce them are unrealistic. For instance, additional lights, or unreal light sources are used to produce certain effects. The goal to do this is to produce the most suitable looking image. To produce these Good Looking or Perfect images the relation to the actual physical property of light is lost. The manipulation to produce this effect without proper tools would in turn give non-quantifiable results for Light Levels. But in order to build a real model with quantifiable values of Light one would need more complex data such as the:

• Photometry of the light source the way it behaves, the quantity of light energy leaving the source.

34




• Material quality with which the light will interact. Transmission, colour, physical character, reflectivity etc.

• Transformation of the complex calculations and algorithms into visual form which can be seen as visualizations on the computer screens.

The purpose is also to seek a methodology of design using these high-tech tools in having more possibilities and control over conditions to find a really integrated solution taking into account the true natural environment of sky conditions and colour and light condition during the complete 24 hour cycle of the earth with respect to existing light sources from the sky.

2.3 3-D Modelling

CAD Systems Computer-Aided Design systems are the most common means of generating 3D input for global illumination. Sometimes, a CAD system is included in the rendering system itself, which ensures that the data is compatible and complete. However, writing a good geometric editor is very difficult, so the more common approach is to import 3D geometry in some standard format, such as IGES, DXF, 3ds or VRML, and rely on a commercial CAD program to create the geometric description. AutoDesk's AutoCAD, Discreet´s 3DS Max, SolidWorks, Rhinoceros are probably the most popular for architectural modelling. For our experiments we will be using Autocad Version 2006, due to personal preference and ease of data interchange and interface with lighting software. The main issue when considering which CAD system to use is whether it can produce a usable model for global illumination or not. Unfortunately, the only way to know for sure is to try it. In some cases, compatibility depends on how the system is used -- i.e., using the export features in the correct way and labelling surfaces and layers in a way that the appropriate materials may later be applied to them. Other issues related to exportability include surface normal orientation, planarity, meshing and vertex accuracy. 3D Scanners and Digitizers We often wish for an easier method to input a model of an object we have on hand. After all, if the 3D geometry of an object is already available with us then why go to the extents of making a CAD model. Also sometimes the objects can be complex enough to take more time in modelling. Two types of devices can help us out, 3D scanners and 3D digitizers. A 3D scanner is a device that automatically scans in an object to create a 3D model of that object.

Figure 14 – Autocad Model

Figure 15 – 3dMax model

Figure 16 – 3d Scanner

35




This is very difficult to do in general, because objects may have concavities and reflectance properties that cannot be captured or adversely affect the capturing process. There are only a few devices currently on the market for capturing full 3D geometry. In general, these devices are bulky and expensive. 3D digitizers are much cheaper and simpler in concept, but generating detailed models with them is time-consuming. They typically have an arm with a stylus attached, which is used to locate vertex points in 3-space. Some devices are wireless and cover a larger volume, but accuracy can be an issue. Graph Paper Sometimes the simplest solution is the best. A method that has worked for me for many years is one of projecting an object onto a piece of graph paper and tracing its outline. Coordinates can then be located and, provided the object has some symmetry, a nice 3D model can be constructed. An overhead projector may be used to get a nice silhouette, or if the object is reasonably flat, it may even be traced directly. The data points may then be entered into a CAD program.

36



Lighting Software

A Study

37



Lighting Software – A Study

3.0 Overview The Lighting Design software have come a long way from the Time Share mainframe computers using Teletype to communicate the data to the present day software. Earlier Lighting software was an important and wonderful Lighting Analysis tool in the hands of a Lighting Designers, through which he could, produce endless pages of Calculations and numbers comprehendible only by a competent Lighting Designer. Now the Lighting Software has transformed into a Lighting Design tool for the skilled Lighting Designer, which can produce images that can rival a real photograph. Unlike architectural visualization software, lighting design software models light. It relies on physical principles to predict how light will be reflected between and absorbed by surfaces in arbitrarily complex physical environments. To make and give results of an accurate physical lit environment by either Daylight or Electric Light the software depend on certain assumptions and thus are limited by those assumptions in their outputs and results. The Computer Simulation is based on two kinds of main algorithms and most of the available software uses these algorithms to calculate light. Under the broad category they can be defined under Radiosity and Ray-Tracing as explained in the previous section. Both of them have their limitations and show errors in predicting and calculating light depending upon the parameters given to them. They have the capabilities and the result in the end `depends´ on what the designer wants and the time required producing them. In the next section one would come across the terms such as BRDF´s, Mottling, shadow leaks, Meshing, coplanar surfaces, colour bleeding, saturation etc. These in a way do not only exist in the virtual world of computers, but have a direct relation to the real Lighting world.

Figure 17 – Simulation or Photo

38




3.1 Feature Comparison & Ease of Use For the purpose of our study we will be including the software based on the above specifications of algorithms used in them and how far they reach out in solving our needs. The features have been divided into various criterions. Some are good in some aspects and others are bad in some. The study will show us the most advanced correct and able software to represent light. The Software packages were selected on the basis of Industry standards of user base and popularity of each of them. The selection was also based on the research that has been done on each one of them by independent sources to authenticate them. Software Packages like Relux, AGI, Dialux were not included in the study due to their limitations in handling complex 3d model situations and were more generic in their approach for fast and easy calculations. For the Lighting to be simulated correctly one needs to have as realistic a model as possible to see study the effect of light and particularly for our topic of study we needed a software that did not have any such limitations. Our experience only extends to Radiance and Lightscape 3.2, the study for others were taken from already done research. Table 1,2,3 and 4 show the results of experiments done by us and various independent sources to validate the Lighting Software.

39




40




From the above tables which were prepared from the research and experience of using Radiance and Lightscape. Through the above table once can observe that Radiance and Lightscape have the least errors and maximum complexity and capability of handling light. Figure 18 shows the comparative results of Lightscape and Radiance for Daylight Factor Calculation under diffused sky conditions and both of them come quite close to accuracy. One can from these kind of studies easily decide the accuracy and validity of the above mentioned programs

Figure 18 – Calculation CIE overcast

41




3.3 Conclusion to Assessment of the Software Packages To conclude the above study from the viewpoint of a lighting designer, we can say that Radiance is the most suitable software for the Daylight Simulations using the Monte Carlo or Distributed RayTracing Algorithm, so is the same for Lightscape 3.2 which uses progressive Radiosity algorithm with Raytracing provide a combination of both the algorithms to produce a more photorealistic and photometrically correct Light Simulation. From this point onwards we will be concentrating only on Radiance and Lightscape 3.2. This owing to the fact that they still remain the best designed and accurate software packages for the Lighting design community and the Computer Graphic designers to predict accurate results with light. Both are equally complicated and advanced to operate and need good skills to produce accurate calculations and simulations and thus redeem themselves as technically sophisticated and highly developed programs to produce results as in Figure 19 and 20, beyond the artistic and representative skills of most of the artists and lighting designers.

Figure 19 – Radiance Daylight Simulation

Figure 20 – Lightscape simulation showing the Mirror, Glass and Matte texture and their attributes with light

42



Photometry

Reading & Writing43



Photometry – Reading and Writing

Photometry is the science of measuring the visible light in units that are weighted according to the sensitivity of human eye. The human eye is not equally sensitive to all wavelengths of light. Photometry attempts to account for this by weighting the measured power at each wavelength with a factor that represents how sensitive the eye is at that wavelength. The standardized model of the eye's response to light as a function of wavelength is given by the luminosity function. Note that the eye has different responses as a function of wavelength when it is adapted to light conditions (photopic vision) and dark conditions (scotopic vision). Photometry is based on the eye's photopic response, and so photometric measurements will not accurately indicate the perceived brightness of sources in dim lighting conditions. The sensitivity of the human eye to light varies with wavelength. A light source with a given radiance of green light, for example, appears much brighter than the same source with the same radiance of red or blue light. Photometric theory does not address how we perceive colours. The light being measured can be monochromatic or a combination or continuum of wavelengths. In Simulation Software the photometry is mainly defined through four main parameters:

• Luminous Flux

• Luminance

• Illuminance

• Luminous Intensity (Refer to appendix for further reading on the definitions).

Photometric measurement techniques Photometric Units:

• Luminous Flux

• Luminance

• Illuminance

• Luminous Intensity

• Colour

• BRDF/BTDF (Bidirectional Reflectance Distribution Function and Bidirectional Transmittance Distribution Function)

A brief history of “industry standard” photometric data file formats: In 1986, the Illuminating Engineering Society of North America published IESNA Transaction called "IES LM-63-1986: IES Recommended Standard File Format for Electronic Transfer of Photometric Data." It was quickly adopted by North American lighting manufacturers and the developers of lighting calculation software. It was revised in 1991 and 1995, and the latest revision (ANSI/IESNA LM-63-2001) is currently awaiting publication.

44



Photometry – Reading and Writing

This was followed two years later by the Chartered Institution of Building Services Engineers, which published CIBSE TM14:1988, “CIBSE Standard File Format for the Electronic Transfer of luminaire Photometric Data.” It is still widely used in the United Kingdom. In 1990, Axel Stockmar of Light Consult Inc. (Berlin, Germany) proposed a photometric data file format called EULUMDAT. It has since become the industry standard for European lighting manufacturers. The International Lighting Commission (Commission Internationale de l’Eclairage) followed three years later with its publication of CIE 102-1993, “Recommended File Format for Electronic Transfer of Luminaire Photometric Data.” Despite being a well designed and comprehensive file format, it does not appear to be supported by any lighting manufacturer or commercial lighting design software product. There are several other “industry standards” that are either in use or have been proposed, including EULUMDAT/2 (LCI, Germany), LTLI (Lys & Optik, Denmark), TBT (Toshiba, Japan), and CEN (European Committee for Standardization). Fortunately for lighting software developers, the North American and European lighting communities have chosen IES LM-63 and EULUMDAT respectively, and United Kingdom manufacturers have chosen TM14. None of these file formats are ideal, but they have served their purpose for well over a decade. Conclusions Photometric files and data are a very important for correct lighting design simulation. It is these files that define the character of light from the source. Therefore to correctly simulate electric lighting one needs to have the correct data, or vice versa. If the lighting designer wants a specific effect from a luminaire while designing he can modify or generate these files and do reverse engineering and define a new luminaire to correctly simulate the wanted result. This new file then can be given to the manufacturers to produce the needed optics for the desired effect. Though it is not simple to modify these files, and need thorough understanding and skill to modify or write them.

Figure 36 – IES Photometric File

Figure 37 – EULUMDAT Photometric File

Figure 38 – CIBSE TM-14 Photometric File

45



Skies as

Light Source

46



Skies as Light Sources

In the Lighting design situations daylight (skylight and sunlight) have an important contribution and role to play. They are always silently influencing the design strategy adopted by us. Daylight varies dramatically both due to the movement of the sun and the colour it gives to the sky which come to us as Skylight both during the day and in the night through indirect light of the Moon and the stars. But the sky is not black it has a luminance value and its own character. (Figure 21)

Our lighting concepts while working with electric lighting often ignore this complexity and dynamism of the skylight. The changing colour of which offer a backdrop. Though we have gone far ahead in giving more and more accurate calculative sky models, but we done little for the night sky luminances and changing colours of the sky during the day, evening, night and dawn. It was difficult for us to introduce this new parameter in software like Lightscape and Radiance as they use their own sky models specified by CIE, but they do not show the sky as a background for the building forming the foreground. On one hand these softwares predict light accurately on the other they failed to provide the right background of the sky to make a wholistic design approach with the correct context and surroundings. This was an important part of our thesis to make a harmonious design which is relation to Sky colour, its luminance and its dynamism. Making the design more suitable to its location and time. A number of models have been proposed for calculating the phenomenon of Sky Luminances, the most predominant are the CIE Sky models: 1. Standard Clear Sky Model 2. Standard Overcast Sky Model 3. Standard Intermediate Sky Model These models are derived from empirical derived mathematical calculations, parameterised on a small number of local atmospheric conditions as well as the time and location on Earth. (Figure 24) It should be clear that these models can only approximate the real conditions at any location. Given that the original models are largely based on European conditions, they are less applicable in other locations (dry arid, tropical etc.). There have been many proposals for better models, models which can be more reasonably calibrated for a wider range of climatic conditions. Recently, a new set of standard skies has been proposed (the SSLD models), which appears to offer some improvement. (Figure 22, 23) Sky modeling generally starts with recording large volumes of data from actual skies then, via some analysis process, an algebraic expression is proposed. This model can then be programmed in a package that requires access to sky luminance information for some daylight analysis or lighting design task.

Figure 21 – Vallée de lÉure, Chartes, Designer: Agatha Argod

Figure 22 – MAM Modeller

Figure 23 – Sky Modelling

47



Skies as Light Sources

This is often a tricky task as the model formulations are generally complex and not easily visualised by users. Though one is able to get these SSLD sky models accurately but as one can see these are no where photorealism for visual comparison though are good for calculating the Skylight luminance at various points in the sky. We came to the conclusion that this was not the correct answer to out requirement and needs further investigation to take real skies from the location into the software and then simulate the lighting with it. The main idea for doing this was to include the sky and all its attributes as a part of the lighting design not ignore it as a monotonous constant. Both Radiance and Lightscape had limitations of showing the real sky though they are excellent in showing the CIE Standard skies. But art and design cannot be standardized by 3 or 13 skies or for that matter any limitation. We achieved some success in introducing this last parameter in Lightscape by introducing a real sky model, with correct scale and attributes. The trick is to have a panoramic shot of the sky with respect to the building or the object of interest to be illuminated. The skylight is contributed from the CIE sky whereas the sky-dome is simulated as a non–occluding surface. The non-occluding makes the texture true and does not change the luminance of the sky texture. The sky textures need to be prepared by taking 360° Panoramic or sky photos on a highly reflective convex mirror or chrome ball. These have to be taken at different exposure levels and then converted to HDRI (high dynamic range format images). This would be explained further in the next section. The HDRI have the maximum luminance range of scene, which cannot be taken from a normal photograph or texture. Figures 28 a, b illustrate one such example for the process of modelling it. The above process explained is process formulated by us during our research and is based on reading various related topics and combining them to get the needed result. Lighscape does not specify any such technique in its help file and HDRI is a latest addition to digital photography and computer graphics.

Figure 24 – CIE Skies

Figure 25 – Sky Modeller Interface

Figure 26 – Sky Simulation

Figure 27 – Sky Curve

Figures 28a,b – Sky Dome Modelling Lightscape

48



Contrast

Colour

49



Contrast and Colour

From this section we come to a transition from the virtual world of simulation to the real one. Contrast and colour both form the basis for us to distinguish one object from the other. These concepts are the underlying principle for the human perception to distinguish and differentiate. As discussed in the previous section it was imperative for us to approach an illumination plan with respect to its surrounding and context. Starting with sky as the most important (as it forms the background for most of the exterior architectural settings), the second would be the building materials and various elements inside composing its façade or the building itself. For the beginning we will approach it taking the assumption that the locale is completely non-illuminated space and that one has the complete opportunity of adapting the eye to the Mesopic vision.

The eye is capable of adapting to luminances as high as 1,000,000 cd/m² and as low as 0.000,000,1 cd/m². Once adapted, the eye can cope with a luminance range of 1:1000. To cope with the wide range of retinal illuminations to which it might be exposed, from a dark night to a sunlit beach, the visual system changes its sensitivity through a process called adaptation. Taking this phenomenon into account the only possibility to include the sky luminance as a part of the design is to keep the luminance of the foreground in this case the building with in the Threshold Luminance. The luminance contrast at which the object can be detected 50% of the time is conventionally called the threshold luminance contrast. The threshold luminance is the luminance contrast of the target to the luminance of the background. In other words what should be the minimum luminance contrast of the target that it makes it visible from its background? It depends upon following parameters:

! Retinal illumination to which the visual system is adapted ! Spectral content of the illuminant

! Light distribution around the target

! Visual size of target (in units of angle or solid angle)

! Visual size of background (in units of angle or solid angle)

! Luminance of the target

! Luminance of the immediate background

! Luminance contrast of the target

! Colour of the target

! Colour of the background

! Colour difference between the target and the background

! Duration of exposure

! Temporal frequency characteristics

! Location of the target relative to the line of sight

! Movement of the target in the field of view

! Retinal image quality, as determined by the state of accommodation, pupil size, light scatter, and lens fluorescence

Figure 39 – Threshold contast, minimum contast at 50%.

Figure 40a – Luminance of some light sources

Figure 40b – Some typical illuminances

50



Contrast and Colour

For us the most important parameters are: - Luminance of the Target - Luminance of the immediate background - Luminance contrast of the Target - Colour of the Target - Colour of the Background - Colour difference between them

We have chosen these parameters on the assumption, if the Target size is above the minimum target size (IESNA) it will only be visible if it differs in Luminance and colour from its immediate background. The minimum Luminance contrast required to see a target from its background is defined by the Threshold contrast as mentioned before. We would like to use this in our design and make and thus not use excessive light for the impact. At the same time, there exists tools from organisations like NASA that have developed sophisticated tools for getting the right colour contrasts with respect to the background colour. To measure only colour differences, the separation of the colour of the object and its immediate background on a plane of constant lightness in the CIELAB or CIELUV colour spaces or the two-dimensional CIE 1976 u', v' diagram can be used. But we cannot be restrictive in design by saying that complementary colour is the best option, we cannot say if the sky is blue one cannot use blue light of different luminance on the target just because it is not a colour contrast to its background. Also the study of colour contrast is out of the scope of this thesis and we acknowledge our limitations while doing this research and would not further delve deeply into it. Our idea is not to discuss the optimal visual performance; rather we discuss this as an important technical requirement in order to have the subtlety of the sky and electric lighting, for them to exist in harmony, so that the man-made does not destroy the natural. The artworks exploited this quality of contrasts and colour in a fascinating way. Our aim therefore was to study this manipulation of light and colours by Masters and their masterpieces and bring it to real lighting design. The next section would now deal with this subject of how we analyse light in paintings with the photometric quantities.

Figure 41 – Colour Tool from NASA to find the correct colour contrast.

Figure 42 – The colour contrast

Figure 43 - Lightness constancy is based on contrast: Although the small boxes are equally bright, the one on the left appears darker.

51



Conclusions

Guidelines

52



Conclusions & Guidelines

The intent of this study was to find suitable techniques, to represent light. We can start to conclude by saying that no visualization technique can truly represent the physical character either on screen or on paper, but what it can do is show us a proximate prediction of the behaviour of Light when we control or produce it in a certain manner. We feel that it is both the responsibility and his commitment that he should use the latest tools to enable himself to truly represent his design. We say so because, throughout history, the Masters of fine arts were always experimenting and trying to find a new technique to represent their thoughts to in paintings. Imagine if no one tried the Renaissance Painters would still be painting like the cave painters of Altamira and Lauxcaus. In all the movements and era´s they all tried to go out of the boundaries of the past accomplishments, they embraced the new and were open to advancements. They why do we now, living in 21st century are not using these tools that are existing. Why do we create this divide between Art and Science? They are complimentary to each other and we have in a way proven that so far in this thesis. Every period in the History had its own culture, advancements, assumptions, attributes and limitations. According to which developed the art and architecture. Today we have a different culture, advancement, attributes and at the same time limitations. Computers and Programming is one such advancement of our culture, which we should accept and exploit to our advantage. At the same time, they do not design for us. The composition and design is original, is intelligent, this cannot be done by the computer, what it can do is predict it for us correctly. More correct than our sketches of light, or our representation of light. These are the tools that can assist us in getting the desired effect. The choices of technique and software packages used by us were dictated by our needs to fully interpret the light in art and then represent it in real life as truly as possible for us. The conclusion of above study is that the technology is progressing too fast and we as Lighting Professionals (skilled people) need to keep ourselves abreast to a certain minimum standard of this advancement. The software packages are much advanced than the calculations that we can perform manually or even through intuition. They also prove that we can really go wrong with thumb-rules while designing the optimum amount of light. The software can make us in a way more sensitive towards the quantity of light that needs to be used to get a desired result. This can also be achieved through trial and error at the site or the point of installation. But then how do we predict this behaviour, when we don’t have this freedom of trial and error testing.

Figure 48 – The first painting 1500 BC, medium charcoal. Caves of Lascaux, France.

Figure 49 – The first photographic print Gelatin silver print reproduction of Joseph Nicéphore Niépce's View from the Window at Le Gras. 1826

Figure 50 – The first Light Simulation. Dot-Matrix print out 1985.

53




How do we account the parameters such the context, sky, luminance, contrast, elements in a single sketch when working on a piece of paper? Today we can say that –

- The correct tools for rendering have become mediums of the 21st century art for us.

- The software are only medium of representation of our physical world like paints, canvas, sculpture and later photography was to us.

- At the same time the software packages give us an advantage of converting the representation into physical reality.

- There were many reasons that art and architecture evolved. One of the primary aims was representation of culture, symbol, thoughts and advancement of society. The software are only one of the steps of this development.

- They are not here to negate Art, sketching or the process of painting, rather to compliment it and an addition to current practices of Design process.

- Like one can understand the concepts of symbolism, composition, colour, contrast and quality, similarly one can learn the true way of producing those qualities in terms of Luminance, threshold contrast, colour theories and understand the physics of Light and its behaviour with complex objects in a given environment.

- The field of architecture and design are in constant flux. Dogma is dangerous, only the shape shifter will prevail. We need to adapt and adopt the new resources.

- As Lighting Professionals, we are both designers and technicians. We need not just to draw our concept, but also predict the possibility of it in the real world with the available resources.

- There is a constant development happening in all fields of our world, be it Art (which we all know very well from the Cave Paintings to the modern day Digital Art), the first photograph on a metal sheet to present day HDRI, for lighting from the first photometric experiments in 17th century to present day Algorithms of programmes like Radiance and Lightscape. The choice is ours to accept or ignore these.

Figure 51 – Not the last painting, not the last photograph, not the last simuation and rendering; which is more representative?

54




Guidelines: - Accurate 3d modelling is required to study the

correct behaviour of light within a defined space. - Context has an important bearing on lighting design.

One needs to consider true day, evening and night sky condition.

- We should not negate the natural light sources just because we have the power to use enormous amount of electric light.

- The contrast ratios should be studied before we think of illuminating the space.

- Luminance rather than illuminance should be the criteria for design, should be checked with methods like HDRI and Luminance mapping from Radiance.

- Correct photometry and luminaire description be used while doing the simulation in order not to get erroneous results.

- The colour of light and material are important criteria for light and visual perception. Correct material mapping should be used for every material, as different material has different reflectances, behaviour, surface shadows and interaction with light.

- Reflectance and illumination together give the luminance. So while designing with contrasts and luminances one need the reflectance of every material, to know the optimum illuminance on the surface. The same illuminance for two different surfaces would not give same luminance.

55



Part C Bringing together

Experiment, Design & Installation 56



LBR - The Luminance Brightness Rating System

1.1 Short reference on colour theory Colour is a property of light. Our eyes see only a small part of the electromagnetic spectrum. Visible light is made up of the wavelengths of light between infrared and ultraviolet radiation (between 400 and 700 nanometers). These frequencies, taken together, make up white (sun) light. White light can be divided into its component parts by passing it through a prism. The light is separated by wavelength and a spectrum is formed. Sir Isaac Newton was the first to discover this phenomenon in the seventeenth century and named the colours of the spectrum. (Figure 1)

COLOUR - Has three distinct properties: hue, value and saturation. To understand colour you must understand how these three properties relate to each other: Hue - is the term for the pure spectrum colours commonly

referred to by the "colour names" - red, orange, yellow, blue, green violet - which appear in the hue circle or rainbow. Theoretically all hues can be mixed from three basic hues, known as primaries. When pigment primaries are all mixed together, the theoretical result is black; therefore pigment mixture is sometimes referred to as subtractive mixture. (Figure 2)

Value or Brightness , Colour value refers to the lightness

or darkness of the hue. Adding white to a hue produces a high-value colour, often called a tint. Adding black to a hue produces a low-value colour, often called a shade.

(Figure 3)

Saturation - Concerned with the purity. A highly saturated

hue has a vivid, intense colour, while a less saturated hue appears more muted and greyed. With no saturation at all, the hue becomes a shade of grey. (Figure 2)

Saturation is the most difficult aspect of colour to understand since value and saturation are often confused. For our purpose on the next chapter, the concept of hue and saturation are in a second place. Now we will be focused on the lightness and darkness concept of the colours.

Figure 1

Figure 2

Figure 3

57




1.2 LBR system. The grey scale for light designers

Value dominates our visual experience. It is the strongest element of visual contrast and largely determines our perception of form as we explore a picture. It defines our perception of space through the effects of aerial perspective and the differences between the lighted and dark surfaces of three dimensional objects. Even in an abstract or pattern design, lightness dominates hue as the pattern making element in a picture. The world could also be represented just in terms of brightness and darkness. That’s the basis of the black and white photograph that uses a scale of greys in order to represent the light present in every element and with every colour. What does it mean? All materials and colours have a constant of reflection and also a correspondence into the grey scale. Considering the multitude of possibilities that a normal colour scale gives, the theory of working just with brightness or darkness becomes easier. It is also vital to have in mind in a grey scale version of a painting the importance of value (brightness), overall composition and visual impact. Notice how strongly the black and white image seems to guide your eye in the figures 4. OK, but how do we measure the differences in light or dark necessary to recognize values with our eye or realize in paints our intended values in design? We use a value scale or photographer's greyscale. (Figure 5) So we are talking about a scale based just in brightness and darkness, taking out the colours. Then, to make the grey scale easy to remember for the human brain, after some studies about colour perception and eye adaptation was possible to determine a scale of nine grey types easy to remember for the designers. This is what we call the Luminance Brightness Rating System (LBR). Of course, we can see a much larger number of value differences than that. The actual limitation is that a larger number of value steps become impractical to recognize. We will just mention this system and show some general information in order to introduce a helpful tool that can help the light designers to “compose” lighting concepts.

In order to have a common value for the different greys, the LBR system is based on the originally proposed system of Denman Ross in 1907 and posterior improvement in the Munsell’s (table 5 ) colour scale because his long-established tradition for the scientific and artistic study of colour, Munsell said: ”is a standard scale of neutral greys… in steps that look equal to the eye under standard viewing conditions”. (Figure 6 , 7)

Figure 4 - Krovin - An Artist's Studio

Figure 5 - Kodack Grey Scale Table

Figure 6

58




Like we said, in this system the reflectance value of the materials is given in terms of nine grey colours. Table But the LBR can give us more information about luminance than just a grey scale. As you will see in the images from the experiment, the possibility to obtain the range of luminance from the different greys on the scale let us work in a very technical way. The values in the table No. 6 are approximate and theoretical values of luminance that as we will explain in the experiment are very close to the results obtained with technical elements. LBR system is not just a tool to design a project in terms of colours or forms; it has also a technical background that can help faster a design process. But is only a “rule of thumb” that helps to find a way. It is important to use other technical tools in order to obtain the most accuracy result in order to make better Lighting Design.

Figure 7 - Munsell colour graphic system Table 5 - Scale of greys taken from Munsell system Table 6 - Range of luminance acourding to the LBR grey scale.

I 00,00 – 14,00 cd/m2

II 14,10 – 33,37 cd/m2

III 33,38 – 57,05 cd/m2

IV 57,06 – 89,34 cd/m2

V 89,35 – 127,55 cd/m2

VI 127,56 – 164,69 cd/m2

VII 164,70 – 213,67 cd/m2

VIII 213,67 – 277,17 cd/m2

IX above 277,17 cd/m2

59



Re-reading the Painting

H.D.R.I.

60



Re-reading the Paintings and H.D.R.I.

This chapter forms link to the Fine Arts to the mathematical, reading and analysing the Luminance Contrast qualities of the paintings. The idea is to bring the paintings from the canvas to reality. To re-read them only as light maps, in order to understand the light composition of them and re use the same in real light design. It is easier said than done. We can say we are fortunate that the computer, photography and graphic industry today have tools which could enable us to carry this out. Figure 8 HDRI The dynamic range (ratio between dark and bright regions) in the visible world far exceeds the range of human vision and of images that are printed or displayed on a monitor. But whereas human eyes can adapt to very different brightness levels, most cameras and computer monitors can capture and reproduce only a fixed dynamic range. Photographers, motion picture artists, and others working with digital images must be selective about what’s important in a scene because they are working with a limited dynamic range. High Dynamic Range (HDR) images open up a world of possibilities because they can represent the entire dynamic range of the visible world. Because all the luminance values in a real-world scene are represented proportionately and stored in an HDR image, adjusting the exposure of an HDR image is like adjusting the exposure when photographing a scene in the real world. This capability lets you create blurs and other real-world lighting effects that look realistic. Currently, HDR images are used mostly in motion pictures, special effects, 3D work, and some high-end photography. The luminance values of an HDR image are stored using a floating-point numeric representation that’s 32 bits long

(32̂bits-per-channel). The luminance values in an HDR

image are directly related to the amount of light in a scene.

This is not so with (non-floating point) 16̂bits-per-channel

and 8̂bits-per-channel image files, which can store

luminance values only from black to paper white; this represents an extremely small segment of the dynamic range in the real world. HDR image contains brightness levels that far exceed the

display capabilities of a standard 24̂bit monitor or the

range of tones in a printed image. When taking a picture with a digital camera, the image comes with a text file containing the settings of the camera that were selected when taking the photo. This file provides information such as the exposure value, the aperture of the lens, the shutter speed and the ISO speed. This information can be used to work out the luminance of each pixel of the image.

Figure 8 – Art and HDRI

61




The actual photo can then be transformed in a luminance map giving the luminance value of each pixel. Depending on the range of luminance contained in the photo, several images, with different exposure values, can be required in order to cover the whole range of the luminances of the scene. A high dynamic range image is an image that contains a wider range of luminances that would show a single picture of the same scene. A single picture can contain a magnitude of contrast of about 1:300, whereas the magnitude of luminances of the actual scene can be as high as 1:100000. Therefore, using an algorithm linking the value of each pixel with the exposure value, we are able to combine several photos with different exposure values in order to provide a luminance map. Before moving further on the technique used by us to convert the images into HDRI to Luminance Maps, we would like to discuss certain constraints of the physical medium which visually depict the output.

- White Point - Monitor Gamma - Dynamic Range Mapping - Whiteness constancy, adaptation, and surroundings.

White Point - All monitors have a maximum intensity colour they can produce with the maximum intensities for the red, green, and blue electron guns. This is called the white point of the monitor. This white point varies for different monitors. Usually the white points are defined in terms of colour temperature. Colour temperature represents the colour of a glowing object heated to the specified temperature. Most white points lie between 5000°K, an orangish white, and 9300°K, a bluish white. Most televisions are set to 6500°K, a white that is near the colour of daylight. This variation in white is another reason why images on one monitor look different from images on another monitor. Monitor Gamma - The light from the monitor comes from electron guns exciting the phosphors on the screen. This process is not linear. To get light that is halfway between zero intensity and full intensity, it is necessary to have the guns fire at above half strength. This nonlinearity is called the gamma of the monitor. Gamma is also used for similar nonlinearities of other display and recording devices. This is a problem, because when we compute a particular intensity, you want to display that intensity, not the intensity produced by distortions of the system displaying it. Many display programs allow an image to be displayed at a particular gamma. We should always display images at the correct gamma. Dynamic Range Mapping - Perhaps the greatest constraint of the monitor is its limited dynamic range.

62




Dynamic range is the ratio of the highest intensity the monitor can produce to the lowest intensity. In a dark room this ratio is around 100 to 1. In a bright room the ratio drops to around 30 to 1. Real environments have dynamic ranges around 10,000 to 1 or larger. There is currently no good way to compress the dynamic range of a real environment to that of a monitor. Whiteness constancy, adaptation, and surroundings - The brain wants to perceive white surfaces (those with a white reflectance spectrum) as white. A sheet of white paper under fluorescent or incandescent lights looks white, even though neither of these lights is white. White on a monitor in a dark room looks white, even though the white on two different monitors may look very different if you see them side by side. When viewing a monitor in a lit room, one adapts to the illumination of the room, not to the illumination of the model. Even if a model is computed and displayed correctly, it may still be seen as if we are looking into the room from the outside—or, more likely, as if the colour of the model is wrong.

All the above stated drawbacks point out to single most important thing, that even if we make correct simulations and photography it is impossible to see the correct result on the monitor or on the paper as it cannot represent the correct dynamic range of the real world, neither can our vision take all the ranges of it at one time. We would now go on and discuss the methodology developed by us in converting the Image maps to HDRI and HDRI´s to Luminance Maps. For all the above tried tested and reputed software were used namely Radiance to produce the Luminance maps, HDRShop and Photoshop CS2 to convert normal images to HDR. Procedure:

- Secure the camera to a tripod. - Five to seven photos are taken of the same scene

with different exposure settings to cover the entire dynamic range from the brightest part to the darkest area. Figure 9

- Next step is to combine these images as an HDRI. Figure 10

- This HDRI is then fed into Radiance Image Analyser, which converts it into the Luminance Map.

- This Luminance Map then gives us the luminances of various surfaces in the image. Figure 11

Refer to next chapters of Experiments where we convert the Paintings to Luminance map through above illustrated method.

Figure 9 – Photos at different exposures

Figure 10 – Resulting HDRI

Figure 11 – Pseudo-colour Luminance Map

63



Experiments

Analysis

64



Experiment and analyses

1. Generalities about the experiment For our thesis this experiment helped us, after transfer the paintings into the LBR grey scale to determine contrast and the relation between the dark and the light zones on the painting and in this way trying to understand why the eye focuses more some parts of a painting than others. Also this experiment was done in order to prove if there is a possibility to know the luminance value of an image just with the knowledge of normal software and the LBR theory. The first element to have in mind is how we are going to convert the LBR grey scale into RGB (Figure 12) colour computer system. As known, the LBR is based on the Munsell scale of greys, different to the other. So it is necessary to find the exact representation of the Munsell colours in RGB. To achieve this task, is possible to download from the webpage of the Rochester Institute of Technology - Munsell Colour Science Laboratory a tool that Converts Munsell Notation to XYZ, L*a*b*, RGB, CMYK. (Figure 13) After knowing the values of RGB to use, (Table 7) the work begins in Photoshop or similar software that allows you to manage photographs. These programs are allowed to convert colours in the range of grey scales that we need. So at the end, we have a photograph or a painting with the LBR grey scale. In the Supper at Emmaus from Caravaggio as an example, is possible to recognize some axes that in colour are lost. It means, the increase on the contrast perception according to the grey scale helps us to understand better the composition used in certain paintings. An also will help us to understand and develop to compose in order to produce lighting designs projects. As explained, according to the table 6 is possible to estimate the amount of light reflected by a surface in terms of LBR grey scale. With the same painting of Caravaggio converted into the nine grey scale we can see how this system can give us some results. To see how precise the results are, we will compare the results with some calculations made by computer software and images HDR. Please refer to the chapter in which this topic is further developed.

Figure 12 LBR and RGB range of grey Figure 13 - Munsell conversion tool Table 7 - Exact values of RGB for LBR system

65



Experiment and analysis

Figure 14 Better possibility of composition and analysis with a scale of greys. In this case the 9 scale LBR.

Original LBR Radiance software LBR in false Colours Figure 15 The Supper of Emmaus, Detail – Caravaggio

178,3 cd/m2

9,4 cd/m2

>277,2 cd/m2

>277,2 cd/m2

00,00 – 14,00 cd/m2

00,00 – 14,00 cd/m2

66




E x p e r i m e n t 1 Aim: To transform the art pieces into LBR for contrast analysis. Utilities:

- Adobe CS, Munsell conversion tool,

Procedure: 1. The painting jpg Images downloaded from internet. 2. The images are then fed into Adobe CS (which has

the capability of converting jpg images into the 9 LBR grey index colours and convert to grey scale.

3. To detail easier the 9 different colour greys, we select the different gamma of greys and convert it into RGB and its middle tones

Observation and Analysis

1. Like we said in a previous chapter, the use of grey scale increases the perception of contrast. With this method we prove the analysis done before. All the compositional elements based in brightness and darkness can be studied in detail because of this system.

2. With the LBR system the study of contrast could be done more precisely knowing the approximate differences value between levels of grey. With higher contrast, the relations between elements are more evident.

3. Possible to calculate or determine mathematically relations between grey levels in order to find constants or proportions between them.

4. To prove how the use of contrast in order to balance a composition is efficient when we talk about a 2d representations.

Inferences 1. Every painting has main characters, as far and

close backgrounds. Could be a colour composition were this differentiation is not obvious, but in LBR grey scale is possible to determine the layers existents in the composition and understand better the depth of each one.

2. One eye is more attracted when the difference between greys in LBR scale is bigger. When the difference presents other intermediate grey scale, the transition is smoother and brings to the viewer a “2nd layer” perception.

Figure 16- LBR for Magritte’s painting

Figure 17 - LBR for school of Rembrandt painting

Figure 18 – LBR for Spitzweg painting

67




This section covers experiments done by us in: - Validating processes used by us, such as checking

the results of HDRI and Luminance map conversion. - Converting various case examples of paintings

takes to study the luminance maps and understand the use of light and contrast to produce the effect.

E x p e r i m e n t 2 Aim: To validate HDRI and Luminance Mapping. Utilities:

- Adobe CS2, HDRShop (HDR conversion softwares) - Image Analyser from Radiance (converts HDRI to

Luminance maps) - Canon S2IS Digital Camera - Tripod

Procedure:

1. Photographs of the selected scene were taken at 5 different exposure settings to cover the dynamic range of brightest areas to the darkest ones.(Figure 19– EV stands for Exposure Value)

2. The images are then fed into Adobe CS2 (which has the capability of merging the images from 8bit/24bit images to 32bit HDR image. (Figure 20)

3. This HDRI was then saved in Radiance format for the Image analyser to open it and convert to Luminance Map.

4. The image was then opened in Image Analyser and converted to pseudo colour Luminance maps, with the upper limit of 1000cd/m2 and divisions of 8.

5. The first luminance map is the exact Luminance in the space. (Figure 21)

6. Next image was the conversion as per the human eye adaptation to the same space. (Figure 22)

Observation: 1. The test pictures contained Sodium Vapour Pole top

luminaire, the Luminance values near the light source were observed to be approximately 5000cd/m2, whereas the night sky luminance at the horizon was between 150-200cd/m2.

2. The pavement and road surface immediately below the Luminaire in a diameter of 4m radius around it, showed the Luminance values in the range similar to night sky luminance at the horizon between the ranges of 150-250cd/m2.

3. The Adapted luminance for the same places came down to approximately at 190cd/m2 for the same spot on the Pole Top Luminaire.

4. The Pavement and the road had luminance between 130-170 cd/m2.

5. The night sky at the horizon had luminance ranging from 100-150 cd/m2.

ev -2

ev -1

ev 0

ev +1

ev +2 Figure 19 – Five night scene images takes at different exposure settings. Time 3:00am Location: Wismar

68




6. The sky towards Nadir had luminance ranging from 50-70 cd/m2.

Inference:

1. The luminance calculated when compared to various documented averages was quite near to them. This was the first step of validation.

2. We can say through this experiment that the process adopted to calculate luminances was quite accurate and produced quantifiable results that could be studied.(Figure23 & 24)

3. Validation with Luminance meter proved that the luminance is in the same range as produces by the HDRI method.

4. We feel that this methodology can be used for further for our experimentation and design process.

Figure 20 – HDRI conversion in CS2.

Figure 21 - Luminance map

Figure 22 – Adapted Luminance

Figure 23 – Readings from Luminance Meter

Figure 24 – Readings from Radiance

69




E x p e r i m e n t 3

Aim: To convert selected Artworks to Luminance maps for contrast analysis. Utilities:

- HDRShop (HDR conversion software) - Image Analyser from Radiance (converts HDRI to

Luminance maps) - Images from Internet

Procedure: 4. The LDR Images (low dynamic range images)

downloaded from internet were converted to HDRI using HDR Shop.

5. The images were then converted to Luminance Maps using Image Analyser (radiance).

6. The images were then saved again in .bmp LDRI format for studying the technique of contrasts used in the Artworks.

7. Number images processed = 5 8. Names of Images Processed in order: - LÉmpire des Lumieres – Rene Magritte - A man seated at a table – Rembrandt - The Café Terrace on the Place du Forum– Van

Gogh - The Bookworm – Spitzweg - The Elevated Railway Station at Bülow Strasse –

Ury Observations and Analysis

1. The luminance maps of the paintings added a new dimension to them. We could now see the painting purely in terms of light. Study where the artist was trying to focus with bright light and spaces where he intended not to be focused on in the painting.

2. One can easily observe the contrast ratios and make an assessment of contrasts to bring the desired effect in the composition. These will be discussed with each case painting individually.

3. One can see weaved layers of varying contrasts to bring out the subject, not everything is bright, brightest parts are the smallest, or they are always enclosed by intermediate light levels to show the effect.

Case 1: The Bookworm – Spitzweg (Figure 25) - After observing the Luminance map we made some

fascinating discoveries which were otherwise not apparent.

- The highest Luminance levels were found out to be at near the book and the head of the Bookworm, this where the artist was trying to bring our focus and thus is the brightest in the scene.

- Also this point of focus is the smallest in the scene. As compared to the size of painting the brightest and the most prominent part has been made the smallest.

Figure 25– The Bookworm

Figure26 – Luminance Map

Figure 27 – Layer 1, point of focus in the painting.

70




- The next level of Luminance is termed as the intermediate level where the luminance levels lie in the middle zone, of being neither the brightest and nor the darkest. (Figure 28)

- This zone forms the second layer of brightness in the painting.

- The third zone is composed in a complex way, the artist uses a principle of exclusion/inclusion*, this zone forms the darkest parts of the painting and is the part where we have least focus, at the same time he leaves the body of the Bookworm (Figure 29) also the darkest, but surrounded by the Zone – 2 of Intermediate Luminance. By doing this he highlights the body of Bookworm, but not through light but by it being dark.

Inference:

- While composing the painting the artist did not make the brightest parts the biggest, or the parts of focus were smaller and the brightest. Therefore while doing lighting design we could follow the same analogy of making the brightest parts the smallest so as to bring the focus to individual or important parts of the building.

- The artist uses the intermediate layer to give the information in the background of the context, but not the whole of it. He carefully selects it, and only shows a part of it again. Also by making it less bright he creates an hierarchy in the space and gives priority to different objects in the composition, so this tells us that the book-shelf comes only after the Bookworm himself.

- The third layer of the least luminance is the one given to the rest of the painting around the intermediate zone, but also as an island inside the Zone 2 as the body of Bookworm. By doing this he creates a situation of interesting contrast. He puts a dark zone with in a bright Zone 2 and thus again brings focus to the Bookwork. In this way we can see that one can also use this technique in Lighting design of creating dark zones within the uniformly lit big intermediate Luminance zone.

- From the above example we learn that not everything needs to be brightly lit with in a space, one can bring focus through play of bright and dark zones with in the Intermediate lit zone and create hierarchy.

- Therefore one needs to work with layers, the smallest being the brightest and the largest being the darkest and the middle layer of Luminance having the intermediate area in the composition. (Figure 30)

- The contrast ratio between the brightest to intermediate was 1:2 with the brightest being 130-150 cd/m2 and the intermediate being 55 – 70 cd/m2.

Figure 28 – Intermediate level of Luminance

Figure 29 – Focus 2 – the darkest level

Figure 30 – The three layers of contrast/brightness with rest of the painting obscured in the darkness.

71




- The contrast ratio between the intermediate and the last zone was ranging from 1:3 to 1:4 with the Luminance for intermediate being 55 – 70 cd/m2 and for the Darkest zones being 10-25 cd/m2.

Case 2: LÉmpire des Lumieres – Rene Magritte

- The analysis of this painting is in many ways similar to Case 1 – The Bookworm. Magritte has also worked in layers to bring the character to the painting and same in various levels of luminance.

- The brightest is the smallest and the point of focus and that being the Lantern, the use of form, lines and composition all bring our focus to the centre of the painting. (Figure 335)

- At the same time Magritte creates this contrasting sky, much bigger in size and intimidating, it forms an important part of composition of the painting and is same Luminance as the Focus 1. The sky forms the Focus 2 in the painting. (Figure 34)

- The second level of Luminance, the intermediate level encloses the Focus 1 the lantern and like the Bookworm illuminates only a certain part of the Villa in the foreground. This layer is also intermediate in size with respect to its luminance. (Figure 35)

- The third layer is the darkest and the largest in size. This layer encloses both the Focus 1 and the intermediate layer. This is the place of least focus and observer reads it in the end. Though it is not the background, but it assumes the role of the background for the painting highlighting the Focus1, Focus2 and Intermediate. This layer provides the contrast to the entire composition.

Inference:

- Magritte in this painting brings out two zones of equal brightness contrasting to each other in size and colour. One can see a really scientific approach and an important hint for Lighting Design of bringing out parts of building even in bright sky conditions.

- He uses the same luminance as the sky and does the lighting by highlighting only the windows and the door of the Villa.

- If he had evenly illuminated the entire villa with the same or even more brightness as compared to the sky, one could not have perceived the composition so well.

- Again the intermediate layer brings a hierarchy in the space telling us that the Villa is also an important part of the composition but after the sky and lantern. It encloses the focal point of the Painting that being the Lantern. This directs the viewer to a single point in the painting rather than making him look at many objects within a composition.

Figure 31 – LÉmpire des Lumieres; René Magritte

Figure 32– Luminance Map

Figure 33 – Focus 1 - Brightest

Figure 34 – Focus 2 - Brightest

Figure 35 – Focus 3 – Intermediate

72




- In this painting the trees and foliage and parts of villa form the last layer to give the necessary contrast and balance in the painting.

- Despite the Luminance is same for the sky and the lantern, they are read as totally different spaces because of the contrast in size and second the colour.

- We again get the same conclusions as the Bookworm in this painting and find a similarity while artists were composing with light.

- The contrast ratio between the brightest to intermediate was 1:3 with the brightest being 75-125 cd/m2 and the intermediate being 25 – 50 cd/m2.

- The contrast ratio between the intermediate and the last zone was ranging from 1:2 to 1:4 with the Luminance for intermediate being 25 – 50 cd/m2 and for the Darkest zones being 5-15 cd/m2

Case 3: A man seated at a Table, Rembrandt (Figure 36)

- Rembrandt in the illustrated paintings again creates 3 zones of Luminance contrasts. (Figure 37)

- The first being the direct light coming from the window on to the wall.(Figure 38)

- The second diffused light around the wall and light on the wall opposite to the window highlighting an obscured form. (Figure 39)

- The third forms the most important part of the painting showing the subject in the painting “a man seated at a Table”. But the subject this time forms the darkest part. In contrary to the case studies before. (Figure 40)

Inference

- Though there are three zones of brightness in this painting as well, but this time each of them have a different role to play with respect to the paintings discussed above.

- Now the focus is brought upon the subject by showing him as a silhouette in the foreground whereas the background becomes the brightest. The intermediate level is the most inconsequential though highlights a relief work in the opposite wall but still is deprived of much focus in the painting.

- One can even say that since the human eyes perceives a human form first; Rembrandt cunningly rendered the human dark as our eyes would anyways register it first and then the brightest of all in the painting.

- One can even perceive a sense of glare in the painting due to the high contrast that is created between the man and the wall, which further heightens the effect of light in the painting.

- Though Zone 1 is still the smallest part of the painting, but it is able to provide a balance within the painting due to the high contrast.

Figure 36 – A man seated at a Table; Rembrandt

Figure 37 – Luminance Map

Figure 38 – Zone 1 Brightest

73




- Therefore in real life lighting design we can say we have yet another possibility of composing the scene with high contrasts within the space and again the brightest parts are the smallest as compared to the darkest ones. This gives us a uniformity that we don’t need to light everything while doing Lighting Design, we need to consciously decide and select the parts within the architecture that need to be lit the brightest and the ones which need to be the darkest.

- By making parts dark or leaving them unlit does not imply that we are trying to hide them. One can bring the focus to these parts by lighting everything else and leaving them dark, as in the case with the painting of discussion.

- The contrast ratio between Zone 1 and Zone 3 is almost 1:15, with luminance at 100-150 cd/m2 and 5-15 cd/m2 respectively.

- The contrast ratio between Zone 1 and Zone 2 is 1:5, with Luminance at 100-150 cd/m2 and 20-30 cd/m2.

E x p e r i m e n t 4 In this part we will prove our theory and analyze the results. To make this we will analyze an image done by ourselves.

Aim: To validate LBR system and its range of Luminance Mapping. Utilities:

- Adobe CS, Munsell conversion tool, - Canon S2IS Digital Camera - Tripod

Procedure:

7. Photographs of the selected scene. 8. The images are then fed into Adobe CS (which has

the capability of converting jpg images into the 9 LBR grey index colours and convert to grey scale.

9. To detail easier the 9 different colour greys, we select the different gamma of greys and convert it into RGB and its middle tones (Table 8)

10. The first image we will found is the converted LBR image. (Figure 43)

11. The second image we will find is the LBR image transferred into RGB colours. (Figure 44)

Observation:

7. The test pictures contained Sodium Vapour Pole top luminaire, the Luminance values near the light source were observed to be above 277,17 cd/m2 whereas the night sky luminance at the horizon was between 89 and 164cd/m2.

Figure 39 – Zone 2 Intermediate

Figure 40 – Zone 3 Darkest

Figure 41 – Images takes at different at 3:00am Location: Wismar

Figure 42 – Image with the 9 LBR grey index colours

74




8. The pavement and road surface immediately below the Luminaire in a diameter of 4m radius around it, showed the Luminance values in the range similar to night sky luminance at the horizon between the ranges of 127 and 164cd/m2.

9. The Pavement and the road had luminance between 130-164 cd/m2.

10. The night sky at the horizon had luminance ranging from 164-277 cd/m2

Inferences:

1. When compare LBR with the adapted HDRI system, in high luminances (up than 213 cd/m2) the difference between both systems varies until a 50% showing a brightness image the LBR system.

2. When the amount of luminance’s is lower, the result in comparison with the HDRI system is between the values that the LBR system has.

Table 8 - LBR into RGB and luminance ranges Figure 43 – LBR Image

Figure 44 – LBR into RGB

Figure 45 – Adapted Luminance HDRI system

75



The Design

Installation

76



The Design and Installation

This sections deals with final experiment of our thesis to check and conclude our hypothesis and approach to Lighting Design, by using the processes explained by us in our thesis till now. This will be demonstrated through a real Lighting Installation at Heiligen Geist Kirche in Wismar. The Lighting design process was fully documented to show the time and methodology used to produce various results for analysis, design and installation. This will also show the time constraint in which it was performed as it has a direct relation to the quality and size of the installation. Before we describe the process of Installation we would like to inform about the constraints under which the Design and Installation were done, as it has a direct bearing on the quality and size of the Installation:

- Time constraint: The installation was taken only as an experiment to validate our hypothesis and the answers we wanted to seek when we started this thesis.

- Equipment Constraint: In order to truly produce the concept from an artistic point of view, one does not work under the constraints of the available equipment. Thus we had to substitute by using available equipment and filters to dim, colour and direct light in order to achieve similar level of design.

- The aim was not to produce a fantastic Lighting Design or say the best lighting design suitable to that space, which it was designed for. Rather it was to produce a design based on our study and research of Fine Arts and then translating it through software technology to get a predictable lighting result.

To begin with we divided our design process into following parts:

- Analysis of existing site conditions – Luminance and Points of Focus.

- Design Concepts and Sketches based on guidelines and our conclusions from the analysis of lighting in paintings.

- Computer Simulation based on Design concept and optimum luminance.

- Design Installation and Analysis

Figure 46 a,b,c,d – Views to Heiligen Geist Kirche. The Site of Lighting Installation.

77




4.1 Analysis of Existing Site conditions – Luminance and Points of Focus

The first few visits to the site were critical in making the choice of space for Lighting Installation within the huge complex of Heiligen Geist Kirche, its backyard bound by Musik School, the Main Church and the residential block facing the entrance. After a careful analysis of the space we decided to do the Lighting Installation for the Arch-Gate Entry and highlight the space immediately visible for the pedestrians in the night from this Arch Gate way. The Gateway was chosen mainly because of its Architectural aesthetic quality. (Figure 46a,b) The space enclosure within this courtyard gave us ample opportunity and freedom to show our idea of composition, hierarchy, focus, layers and contrasts. Also the size of the space was ideal with respect to the time and equipment constraint we had. The next step for us was to identify the points of focus that need to highlighted and emphasized by us. The identification of these points was based on our analysis of Artworks analysed in previous chapters. The idea was not to illuminate the entire space, but illuminate the minimum amount to get the meaning of installation. Therefore three points were selected:

- The Main Archway (Figure 46a,b) - The tree adjacent to the main Archway (Figure 46a,b) - The tree in the background, in the direct axis of the

Archway.(Figure 46a,b) It is fascinating to know that none of the building facades are much visible to the pedestrian when he is walking outside, other than the small view from the Main Arch, when one is directly in front of it. Therefore to illuminate elements of a building facades would not have had any impact. The next step was the contrast study of the selected areas to decide the contrast ratios for the Luminance of the light for the installation. The Luminance reading was done two days prior to the installation. Based on these luminance values the contrast was simulated and decided for the Lighting Installation at the site. (Figure 47 & 48) Observations:

- After converting the images of the selected space for installation the following Luminance Levels were found. These luminance values were partly because of Sky Dome Luminance and other electric light sources installed in the vicinity.

i. Night Sky Luminance 3.5 – 7 cd/m2 ii. Ground Luminance 1.5 – 2.5 cd/m2 iii. Tree Luminance < 0.5 cd/m2

Figure 47 – Images at different exposures for the selected areas.

Figure 48 – Luminance Mapping

78




iv. Background Building Luminance 0.5 – 1

cd/m2 perceptibly brighter than the tree. These values would later be used for determining the optimum luminance of the electric lighting in Lightscape.

4.2 Design Concepts and Sketches: Design concept like the choice of spaces was dictated by the Artwork analysis. The following was our attempt as per the conclusions formed of the analysis and understanding of the paintings:

- Hierarchy in contrast (luminance) with respect to size; the smallest to be the brightest, the transitional to have the intermediate size and the darkest to be the biggest.

- This was to be achieved by keeping the tree the brightest in the background with the building behind it having lower illuminance to form the intermediate.

- This was done to highlight the linear perspective from the archway.

- The next point of illumination the Archway was to be highlighted by having point light coming asymmetrically from inside, on the pavement. This was more for a symbolic reason to show and highlight the entrance for the people walking on the street as the archway is not immediately visible; this in a way marks the entrance to the complex from a distance, with Golden Light coming from inside, inviting, warm to a holy place (Heiligen Geist). (Concept Sketch 1, 2 & 4)

- The next idea was to light the tree from the top with green light to signify the character of the tree as a shade giver/shelter in times of trouble, something that a church is to the society. Thus the idea was to replicate the shadows as in the day time but with coloured light to show the same diffused natural shadow pattern on the arch and the pavement.

- These two together evoke a curiosity for the pedestrian and the people driving past to experience this low level light highlighting a space in a subtle way, terminating in the brighter white-light lit tree symbolizing peace, purity and calmness. At the same time highlighting the one point perspective of this composition.(Concept Sketch 3 &5)

The following are design concepts that were developed and analysed for the contrasts to translate into the quantifiable computer simulation/calculation:

Figure 49 – Analysis of Pre-Existences

Figure 50 – Concept

Figure 51 – Concept

79




Concept Sketch 1 View from street, showing the entrance tree and the existing light condition.

Concept Sketch 2 View from street, showing the design idea of highlighting the entrance with golden-yellow light coming from the gate and the Green downlight filtering from the tree.

Concept Sketch 3 Front View depicting the Archway and the tree symmetrically in line with the Archway.

80




Concept Sketch 4 Front View depicting the archway and the tree

symmetrically in line with the Archway.

Concept Sketch 5 Front View depicting the Archway and the tree symmetrically in line with the Archway.

81




Luminance Contrast:

- The Luminance contrast ratios in the sketches were found similar to that of the paintings.

- Them being 1:2 between the brightest and transitory zones.

- Ratios from 1:3 to 1:5 were found between the dark and transitory zones.

These contrasts and luminance values formed the basis for us. As we already had the luminance of the sky and dark zones for our site (from 4.1). It was easier for us to work back with these ratios and derive the luminance values for the Lighting Design.

4.3 Computer Simulation and Luminance Analysis To do correct lighting analysis it was imperative for us to do correct computer modelling of the selected space and area. For this the plan was obtained from the Wismar Road and Transport Department and the elevations were taken from the archives of Hochshule Wismar Architectural Conservation Department. Step 1

- The 2d drawings were converted to 3d drawings preserving a certain level of detail.

Step 2

- The 3D drawing was then outputted to 3ds-Max for material Mapping.

- The materials were carefully chosen as per there physical and optical characterics closest to the existing site conditions.

- The Sky dome model and moon model and map were further introduced in the drawing at this stage.

- For the correct sky model the exact sky image was used.

P L A N

S O U T H E L E V A T I O N

W E S T E L E V A T I O N

Figure 52 – Plan and Elevations Heiligen Geist Kirche, Wismar

Figure 53 – 3d-model – ACAD 2006

Figure 54 – Material Mapping in 3dsMax

82




Step 3 This is the most important and relevant phase of all as we do the Lighting Simulation here and try to find a balance for optimal Luminance and contrast. In order to correctly see the effect of light one need to see simulations in a completely dark room, so that the eye can adapt from Photopic to Mesopic vision and correctly see the Luminance as would be in night. The guidelines to do this were dictated by the concept sketches and guidelines described in the previous section of this chapter. Based on these guidelines:

- Suitable Luminaires with the required photometry were selected in Lightscape.

- They were positioned in a way that could be replicated later easily on the site and placed to the exact places as in the software.

- The parameters of physical property like Transmission, Absorption, reflection, refraction, colour bleed scale and self Luminosity(for the moon) were given for every material to get close to correct luminance values.

- This information was taken from already documented and published sources which have the average values for above described parameters.

- The correct colour was selected to produce the colour light as per the sketch.

- The luminaire luminances were optimised in accordance with Chapter Colour and Contrasts of Part B. So as not to put access of light that ignores and negates the context around it.

- This was achieved through a number of iterations in Lightscape till an acceptable level of luminance was achieved.

Figure 55 – Luminaire Position at courtyard tree.

Figure 56 – Luminaire Position at Entrance tree

Figure 57 – Luminaire Position at Entrance

83




Figure 58 – Simulation and Luminance Map, Front View: Showing the White lit tree, the entrance tree and the yellow light to mark the entrance. Figure 59 – Simulation and Luminance Map, Isometric View: Lighting Installation in harmony with its context, not competing with its surroundings and existing sky and moon.

84




Figure 60 – Simulation and Luminance Map, Perspective: Figure 61 – Simulation and Luminance Map, Perspective: Showing the overall lighting design.

85




The simulations were satisfactory and in accordance to our design concepts. The images shown above are true night time simulation images and have not been touched up or further enhanced in Image editing software, therefore they appear darker due to the light Adaptation of the eye. The luminance contrasts were found to be in the same range as the sketches, though the quality of Simulation surpasses our sketches many-folds. But the intent of simulation is governed by the sketched design. The parameters put in Lightscape to generate the design were later used in to do our Installation. 4.4 Design Installation and Analysis The Lighting installation was done exactly as per the luminaire arrangement in Lightscape. A test run was done to check the luminance values of various luminaires on installation. The ones found to be too bright were controlled with Grey filters to bring down the luminance to an acceptable level. It really helped us in putting our luminaires. They were positioned on the site exactly as per there positions in Lightscape. In total five luminaires were installed for the complete lighting installation. - One 70W HIT (with Grey filter) and 150W Halogen Light

for the Focal Accent. - One 100W Halogen (with yellow and orange filters) for

the Focus-2 of the installation to mark the entrance. - One HIT 70W and One HIT 35W (both with green

filters) installed at 12m height for the intermediate Luminance zone, to create shadow and light pattern and highlight the entrance tree.

Figure 62 – Simulation: view from the street to the Archway.

86




Figure 56 – Lighting Installation: Front View, showing the Entrance Lighting and the Coutyard tree. Figure 57 – Lighting Installation: Interior View, showing the Entrance tree down lighting and the Luminaire Position of Entrance Gate

87



Final Conclusion

Comparison

88



Comparison and Final Conclusion

The above figures are there not just for comparison but show the essence and journey that describes our thesis. They are a result of careful study of two different schools of thoughts, the Art and Scientific Technology. Is the image produced from computer not art?, or is the final installation the true art? For us all the three are true in their meaning and their representation. They are a result of careful analysis and an intent to a design based on background, association, symbolism, context and composition. It is true that science can not understand these human emotions, but it does give us tools to make them possible. We can say through our thesis that it is indeed possible to take hints from Art into Lighting design. There is thin line between what is Art and what is Non-Art. One can feel this difference when one views an object. Art (Fine Arts, Sculpture, Music, Dramatics, and Architecture) is not governed by any law or rule. But still each of them have their building blocks which give limitation and specific advantage to each of them. For instance Music is made up of seven notes, but one can create innumerable melodies out of them. But then playing

89




these seven notes does not always produce music. It’s the harmony, composition, context, symbols, instruments etc. that makes it music. The same is for Lighting Design, why when we design with Light we don’t consider these basic underlying principles for any kind of art. Therefore we thought we should understand the use of light by the great masters of Fine Arts who really studied Light, not separated and cut out, but as a part of a greater whole. Light is not everything, but is definitely an important ingredient. While designing with light we also need to think wholistically as the Artists did. Light forms an important part of the composition, but it is certainly not the only thing that forms the art. The same is for us, while designing we cannot isolate light from other things and then design. That’s not design, that is something cosmetic, to put a light here and to put a light there just to create a different effect. It is like giving a music instrument to a small child who does not know how to play the right notes together, but he definitely creates some sound with it. That is not music that is just some noise. We feel this is what is happening, when light is put in an otherwise dark space, people see a difference, they are attracted by it, as that is a human nature to orient towards a bright space (phototropism). But is it really a Artistic design, by artistic we mean does it really have the quality of human emotions and thoughts in it. Does it evoke a feeling other than that of just orientating ourselves? Does it have the beauty of a full moon night? If not, then we should not be the ones to destroy the view to the star lit sky by putting glaring lights on big facades to create an effect. While comparing our sketches to simulation and the lighting installation, we find that the closest to the real is the lighting simulation. We relate our initial sketches to the preliminary sketches of an artist that he made before making a painting, to study and analyse his space and subject, the same for us the initial study was made on paper, but out final painting was made with computer, as we find our selves incapable of producing such masterpieces. So for us our simulation is the equivalent to the painting which was created from the initial sketches. The sketches are the first translation of the idea of the brain and our perception to a more tangible form. It is the direct translation of our thought. But then we can’t stop there, our responsibility extends much further than this. For us we have to realize it as well, thus we cannot be unrealistic while making our paintings (simulations). Our paintings in the form of simulation have to be as realistic as possible so as to find the correct prediction of our design, so for us our final goal and painting is the real lighting installation. The sketches and simulations are both transitory for us to reach the final goal. Luminance and Contrast have been a major theme of discussion in almost all our analysis. It was a discovery for

90




us to do so. We all know that human eye can only perceive Luminance. So it was imperative for us to use it as a metric while using light and not illuminance. Working with this concept evoked several fundamental questions in our mind, one of them being; why do we design with illuminance, while we perceive only luminance? Is it because we have become so insensitive to that we are completely ignoring human perception and reaction to light? Then whom are we designing for if it does not consider this foundation. Perception forms our thoughts, associations, symbols - so when we design with illuminance, it infers that we agree to completely ignore these. Our thesis is founded on these very principles and thus uses Luminance for deciding the light. We can therefore say that we in our design have been sensitive to a humanistic way of design. We can say that we consider thoughts, associations and symbols that light can create for us. We can say that we have been more artistic in out approach as we can make people `feel´ when they experience this light and not just `notice´ it. This thesis was only a beginning for us, we hope to go further on this research, to seek the true representation and manifestation of light in design…

91



Part D ' ClaroOscuro lighting design


REFERENCES

Books:

1. Christopher Cuttle - “Lighting by Design” – Architectural Press - ISBN 0 7506 5130 X 2. Arthur Zajonc – “Catching the Light” – Oxford University Express - USA - ISBN 0 19-509575-8 3. Illuminating Engineering Society of North America (2000) – “Lighting Handbook, 9

th Edition, IESNA” –

4. Evans R. M. - “An Introduction to Colour” – (1948); Wiley 5. Bill Williams - “A History of Light and Lighting” - Edition: 2.3 (2005) 6. David DiLaura - “Light’s Measure: A History of Industrial Photometry to 1909” - IESNA (2005); 7. Terrance Masson - “CG 101: A Computer Graphics Industry Reference” - New Riders Publishing (1999); 8. Ian Ashdown - “Radiosity : A Programmer’s Perspective”. 9. Marc Charles - “LUX Le monde en lumiére, Photographies de Jean” - Seuil Turner & Turner 10. Kress & Adams – “ Light Spaces, Integral Soultions” - Birkhäuser Publications. 11. Derek Phillips - “Lighting Historic Buildings” –; McGraw Hill. 12. Glieck James – “Chaos” 13. Lou Michel – “Light: the shape of space. Designing with space and light” 14. Dani Cavallaro – “Art for beginners” – Era Naciente SRL – ISBN 987-9065-90-5 15. Major, Speirs and Tischhauser – “Made of light: The Art of Light and Architecture” – ISBN 978-3-7643-

6860-9 Reports:

1. A Comparative Study of Lighting Simulation Packages Suitable for use in Architectural Design – Geoffrey G Roy; School of Engineering, Murdoch University.

2. Sky Modelling from digital Imagery - Geoffrey G Roy; School of Engineering, Murdoch University. 3. The Development of Modelling Strategies for Whole Sky Spectrums under Real conditions for

International Use - Geoffrey G Roy; School of Engineering, Murdoch University. 4. Article: Computers and Lighting – Emlyn Altman; LD+A, December 2005, IESNA. 5. Eigenvector Radiosity – Ian Ashdown, Thesis; University of British Columbia, 2001. 6. Fast and accurate simulation of long-term daylight availability using the radiosity method - B Geebelen

PhDa junior lecturer, M van der Voorden associate professor in Building Physicsb and H Neuckermans PhD, professor in Architectural Design and Building Methodology a KU Leuven, Department of Architecture, Laboratory for Design Methodology and CAAD, Heverlee, Belgium b Delft University of Technology, Faculty of Architecture, Building Physics Group, The Netherlands - Lighting Res. Technol. 37,4 (2005) pp. 295_/312.

7. Hierarchical Monte Carlo Radiosity -Philippe Bekaert, László Neumann, Attila Neumann, Mateu Sbert and Yves D. Willems - 9th Eurographics Workshop on Rendering,Vienna, Austria, June 1998.

8. Jain Gaurav, Dissertation: Re-Reading Architecture through theories of Jacques Derrida in Deconstruction, 2002; Sushant School of Art & Architecture.

Internet Links

1. http://www.schorsch.com/kbase/glossary/raytracing.html - Lighting Design Knowledgebase 2. http://en.wikipedia.org/wiki/ - The Online Encyclopaedia 3. http://www.colorcube.com/index.htm - Colorcube: 3d Colour Puzzle 4. http://www.sanford-artedventures.com/ - Art Education and Art Adventure - A life time of Colour 5. http://colorusage.arc.nasa.gov/ColorTool.php -Colour usage Research Lab - Nasa Ames research centre 6. http://www.colorpro.com/info/tools/converters.html - Internet Colours Resources 7. http://www.scteched.tec.sc.us/TCTC/mbynum/Art101toc.htm - Art 101 - Art History and Appreciation 8. http://webexhibits.org/ - Webexhibits 9. http://www.kevan-shaw.com/articles/philos/communicate/commu.html - Kevan Shaw Lighting Design 10. http://www.almendron.com/arte/pintura/luz/luz.htm - The light in the Paintings (Español)

Internet Images Links

1. http://www.nationalgallery.org.uk/default.htm - The National Gallery, London 2. http://www.abcgallery.com/ - Olga´s Gallery 3. http://www.wga.hu/frames-e.html?/html/f/friedric/index.html - Web Gallery of art 4. http://en.wikipedia.org/wiki/List_of_painters - Wikipedie - List of Painters


Documents

Representing Light