Understanding Exposure

GETTING THE RIGHT AMOUNT OF LIGHT TO MAKE THE PICTURE

Understanding Exposure

The Photographic Triangle

Aperture

Film SpeedShutter Speed

Photography’s creative tools include:

Photographer must decide which one takes priority.

Aperturemost important for depth of field Shutter Speedmost important for action – show motion or

stop action Film Speedspeed used allows for different aperture/speed

combinations to provide a variety of creative effects

The Photographic Triangle

Which element you choose as a priority will be the most important decision you make before taking a photograph.

The Photographic Triangle

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aperture takes priority over shutter speed when depth of field is most important to the composition

depth of field is the area of sharpness within a picturelarge shallow

 f stop is the diameter of the aperture expressed as a ratio of the focal length (ex)f/4 is one-fourth of the focal lengthex: f/4 for a 100 mm lens, 100/4 = 25each stop is ½ of the previous

Aperture next

Wide sweeping views back

Isolated views back

Aperture back

aperture larger #(smaller hole), greater DoF smaller #(larger hole), shallower DoF

focal length short lens, greater DoF long lens, shallower DoF

distance to subject farther, greater DoF closer, shallower DoF

3 Factors That Influence Depth of Field

Story tellinghas a beginning, middle and endlarge DoFuse small aperture – f/16, f/22, f/32use normal (50 MM) or

wide angle lens (16 mm, 28 mm)(examples)

3 Basic Categories of Composition and How to Achieve

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Story Telling – large Depth of Field

Story Telling – large Depth of Field

Story Telling – large Depth of Field back

 Isolationa single theme or subjectshallow DoFuse large aperture (f/1.4 to f/4)shoot closer to subject use longer lens (100 mm or more) or

macro lens(examples)

3 Basic Categories of Composition and How to Achieve

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Isolation- Shallow Depth of Field

Isolation- Shallow Depth of Field back

 Who Caresall items are the same distance from

camera- no distant background or noticeable foreground

use medium DoF – f/8 most recommended

use about 50 - 100 mm lens(examples)

3 Basic Categories of Composition and How to Achieve

Who Cares

End of Aperture and Depth of Field

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set as priority when want to “freeze action” or “imply motion” or hand holding camerafast speed to freeze action (ex)slow speed to imply motion (creates motion blur) (

ex)when hand holding camera for sharp image

shutter speeds are seconds or fraction of second2, 1, ½, ¼, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250,

1/500, 1/1000

 each speed is ½ of the previous

Shutter Speed

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Stop Action (back)

Imply Motion (back)

Fast Speed to Freeze ActionWhich speed depends on:distance to subject

farther away – slower speed OKcloser – faster speed needed

direction subject is movingrule of thumb

1/125 moving to/away1/500 – 1/1000 moving across

focal length of lens long lens, faster speed neededshort lens, slower speed can be used

Shutter Speed

Ways to Imply Motion with Slow Speed Intentional blur – subject moves, camera

stationary (ex) Camera movements – subject stationary or

moving and camera moves (ex) Zoom – camera stationary while zooming

in/out (ex) Long exposure – camera stationary while

subject moving (ex) Panning – camera moves to follow moving

subject (ex)

Shutter Speed

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Intentional blur back

Camera movements back

 Zoom - stationary subject

Zoom – moving subject back

Long exposure back

Panning

Panning and Implied Motion back

Handholding camera – shutter speed takes priority over aperture when holding camera and you want extremely sharp composition

If want to use a slower speed than is safe, use a tripod

Shutter Speed

Safe hand holding speed – nearest speed to inverse of the lens focal length

Shutter Speed

Lens Speed(not slower than)

300 250

100 125

50 60 (slowest recommended speed)

28 60

End of Shutter Speed Section

Choice of film speed affects the ability to achieve creative effects with aperture and shutter speed Commonly measured using ISO number

25, 50, 64, 100, 200, 400, 800, 1600each is twice as sensitive to light as the previous

Film Speed

Speed of film determines its sensitivity to light Slow speed

less sensitive to lightgood for daylightrequires longer exposure times/larger

apertures

 Fast speedmore sensitive to lightgood for night, indoors/low lightcan use shorter exposure times/smaller

apertures

Film Speed

Speeds

Slow Medium Fast

ISO 25, 50, 64 100, 200 400, 800, 1600

Exposure time long medium short

Graininess lacks grain some grain grainy

Quality rich color, sharp vivid images

rich color, acceptable sharpness

colors less vivid, lacks good detail

For close-ups, landscapes

people, landscapes hand held action, lowlight

Tripod required sometimes seldom

Film Speed