Photography

ACCT-AGD-6: Students will explore digital imaging and multimedia.

Written by Michael Simmons

May 2010

History of PhotographyQuick Review

Camera ObscuraGreek words:

Camera – RoomObscura – Dark

Room with a hole in the wall to draw pictures seen out side.

Upside down image

History of Photography

1827 - Joseph Niépce - metal plate covered with a chemical called bitumen (silver & chalk mixture) into a camera box

8 Hours to expose the photograph

History of Photography

1839 - Louis Daguerre - Daguerreotypes – metal plate with the silver iodized substance made a latent image when exposed to a mercury vapor. Once the latent image was fixed with a warm salt solution the image would become visible.

History of Photography

1839 - William Talbot - Instead of making positives on metal plates, Talbot made negatives on paper.

Negative - area most exposed to the light was the darkest

Positives (picture) - the area most exposed to the light was the brightest

Digital Camera

Point and Shoot SLR (dSLR) – Single Lens Reflex

Canon PowerShot SX1 ISNikon DS 90 dSLR

Advantages of Point and Shoot

Compact size Lighter weightPre-set setting (f-stop, shutter, ect.)Price

Disadvantages of Point and Shoot

Picture qualityLittle to no control over setting (f-stop,

shutter)Smaller aperture range

Advantages of dSLR

You are in control of the cameraBetter picture qualityFaster than Point & ShootLenses are attachable so you can expand

your focal point an zoom further.When you look through the viewfinder,

you actually look through mirrors and the lens just like with a 35 mm camera

Disadvantages of Point and Shoot

SLRs will be heavierSLRs will cost moreMost point and shoots are easy to useNo movie modeYou must know about f-stop and shutter

What is a mega pixel?

Mega Pixel refers to the camera resolution.Pixel is the smallest unit in a raster imageMega Pixel is 1 million pixelsThe higher the number of mega pixels less

pixelization when the image is enlarged and printed. (10 mega pixel is better than 5 mega pixel when images are to be printed)

Recommended Resolutions

Resolution needed for various print sizes

Resolution Avg. quality Best quality

0.5 megapixels 3x5 in. N/A

2 megapixels 8x10 in. 3x5 in.

4 megapixels 11x14 in. 5x7 in.

6 megapixels 16x20 in. 8x10 in.

8 megapixels 20x30 in. 11x14 in.

10+ megapixels 25x40 in. 13x17 in.

http://cameras.about.com/od/photoprintingtips/a/resolution_tabl.htm

Basic Parts of the SLR Camera

Aperture (f stop)– an opening to let in a controlled amount of light

Shutter - is a device that allows light to pass for a determined period of time

ISO – Film Speed – Semiconductor

SLR and Aperture

Aperture - this refers to the size of the opening letting light into the camera sensor. A larger shutter opening lets in more light, and a smaller shutter opening lets in less light.

Lens Opening (Aperture/F Stop)

1. The larger the opening, the greater amount of light that reaches the film.

2. The size of the lens opening is measured by f-stops.

(The larger the f-stop, the smaller the opening )

3. The f-stops are on next slide

Aperture

2.8 4. 5.6 8 11 16 22

SLR and Shutter Speed

Shutter Speed - refers to the speed at which the shutter opens and closes. This is measured in fractions of seconds. A slower shutter speed lets in more light, and a faster shutter speed lets in less light.

SLR and Shutter Speed

1. The time for which film is exposed to light is controlled by the shutter speed.

2. The faster the shutter speed, the shorter the duration of film exposure, and the less light reaches the film.

3. A dimly lit subject requires a slower shutter speed than a brightly lit subject.

SLR and Shutter Speed

4. The following are shutter speed settings:

5. Each setting represents a halving or doubling of light that reaches the film. For example, 1/8 allows light in for twice as much time as 1/15.

Shutter Speed in fraction of second

1 most light

15 30 60 125

250 500 1000 least light

SLR and ISO

ISO Setting (also referred to as 'Film Speed') - this represents the sensitivity of film to light. In a Digital SLR the ISO Settings stand for a change in the light sensitivity of the chip that takes the place of the film on the inside of the camera.

Relationship between F-stop and Shutter Speed

1. The combination of these two controls determines how much light actually reaches the film.

2.Each designated f-stop or shutter speed doubles or halves the amount of light allowed in by the next designated f-stop or shutter speed.

Relationship between F-stop and Shutter Speed Cont.

F11 lets in half as much light as f8, and twice as much as f16

A shutter speed of 1/60 lets in light for half as much time as1/30, and twice as much time as 1/125

Therefore, f-stop and shutter speed have a reciprocal relationship. If the shutter speed is slowed down ( to allow more light to reach the film), the f-stop must be closed down ( to let less light strike the film) to make an equivalent exposure.

References

http://blog.colormailer.com/choose-between-slr-and-point-and-shoot-cameras/

http://answers.yahoo.com/question/index?qid=20100419171913AAknZY7 http://www.geometer.org/beginner/slr.html http://en.wikipedia.org/wiki/Pixel#Megapixel http://cameras.about.com/od/photoprintingtips/a/resolution_tabl.htm http://www.ez-digital-photos.com/digital-photography-tips-

fstopsdemystified.html http://www.watertown.k12.ma.us/dept/fapa/pdf/

photo_study_guide_part_1.pdf