Aperture &
Shutter Speed
1
Exposure
To determine the correct exposure
for your negative, you will need to
know the correct combination of
Aperture & Shutter Speed to
produce a properly balanced
negative.
2
Aperture




Affects light and depth of field
7 standard f/stops:
f/22, f/16, f/11, f/8, f/5.6, f./4, f/2.8
A larger aperture has a small number and a
smaller aperture has a larger number
When the aperture is opened up one stop, the
amount of light doubles; when it is closed down a
stop, the amount of light is halved.
3
Shutter Speed






Affects light and motion
Controls light by the amount of time it
remains open
Each number represents a fraction of a
second (or a full second)
Each Shutter speed is a 1 f/stop change
Remember the double/half relationship
It is important to your understanding of
photography!
4
Shutter Speed

The relationship between each
shutter speed will increase or
decrease the light falling on the
film by a factor of 2. Example # 1:
If a shutter speed of 1/125 is
increased to a shutter speed of a
1/250 it will decrease the light
falling on the film by one half.
5
Shutter Speed cont’d


Example #2: If a shutter speed of
1/125 is decreased to a shutter
speed of a 1/60 of a second it will
double the amount of time light hits
the film.
Either multiply or divide the speed
by 2 to determine how much light
is entering the camera at any
aperture opening.
6
Shutter Speed Cont’d





Eleven standard shutter speeds found on
camera:
1 sec., ½ , ¼, 1/8, 1/15, 1/30, 1/60,
1/125, 1/250, 1/500, 1/1000
Shutter speed can either blur or freeze
motion
The slowest shutter speed
recommended for hand-holding a
camera without blur is 1/60 (for a 50mm
lens)
The recommended shutter speed for
freezing action is 1/500
The recommended shutter speed for
7
panning is 1/30
Depth of Field


Range of acceptable focus (in front
of, behind and around the subject
in which the camera is focused)
The area of acceptable focus
moves from the focus point 1/3rd
toward the camera and 2/3rd away
from the focus point:
QuickTime™ and a
decompressor
are needed to see this picture.
8
3 Factors that Affect
DOF



Aperture
Focal length of lens
Distance between camera and
subject
9
DOF cont’d
•Increasing aperture (low f/stop) decreases DOF
•Decreasing the aperture (high f/stop) increases DOF
10
DOF cont’d


Shorter lens focal length will have
more DOF
The greater the shooting distance,
the more DOF
11
DOF Cont’d



To isolate a subject such as a flower, use
a smaller f/stop (such as f/2.8)
The shallow DOF will cause the
foreground subject to be in focus and the
background to be blurred, giving your
subject emphasis.
This is called selective focus
12
DOF Cont’d

To bring the entire scene into
focus, use a larger f/stop (such as
f/22)
13
Reciprocity or
Equivalent Exposures



The correlation between shutter
speed and aperture is direct.
Both the aperture and shutter
speed control the amount of light
reaching onto the film.
Both double or half the amount of
light, which means you can
FREELY interchange the settings
on shutter speed and lens opening
for respective effects while
retaining your preferred exposure
setting.
14
Reciprocity or
Equivalent Exposures
For example, the photographer
may prefer to make his sunny-16
shot at an aperture of f/5.6 (to
obtain a shallow depth of field). As
f/5.6 is 3 stops greater than f/16,
with each stop meaning double the
amount of light, a new shutter
speed of (1/125)/(2·2·2) = 1/1000
is needed.
15