Table 4-2.–Action Stopping Shutter Speeds for Normal-Focal-Length Lenses
Speed MPH
Type of Action
Distance
Direction of Action
5
10
25
100
Slow walk, working with the
hands
Fast walk/ work,
slow-moving vehicles
Running, sports, very active
people, vehicles moving at a
moderate speed
Very fast-moving vehicles
and aircraft
Table 4-3.–Equivalent Exposures
EXPOSURE CONTROL
Shutter Speed
1/2000
1/1000
1/500
1/250
1/125
1/60
1/30
1/15
12
1/500
1/250
1/125
25
1/250
1/125
1/60
50
1/125
1/60
1/30
100
1/60
1/30
1/15
12
1/1000
1/500
1/250
25
1/500
1/250
1/125
50
1/250
1/125
1/60
100
1/125
1/60
1/30
12
25
50
100
1/2000
1/1000
1/500
1/1000
1/500
1/250
1/500
1/250
1/125
1/250
1/125
1/60
25
50
100
200
1/2000
1/1000
1/500
1/2000
1/1000
1/1000
1/500
1/500
1/250
1/250
1/125
f/stop
f/4
f/5.6
f/8
f/11
f/16
f/22
f/32
f/64
the light level may be so low that you have to use a slow
shutter speed and the largest f/stop to get the proper
exposure. After determining the correct exposure, you
can decide how to present the subject. Remember, depth
of field can be used to emphasize your subject, and
shutter speed affects subject blur.
Across Field
of View
Diagonally
Straight
Toward or
Away
The term exposure in photography means the
amount of light that reaches the film or other
light-sensitive material. The mathematical formula for
exposure is the product of light intensity and the amount
of time that the light acts on a light-sensitive material.
There are two ways a formula is presented in
photographic publications. They are as follows:
E = I x T
and
H = E x T
Where:
E or H = Exposure (lux-seconds or meter-candle
seconds)
I or E = Intensity or illuminance (lux or meter
candles)
T = Time (seconds)
Both of these formulas represent exposure. The second
formula is presented in the more current publications.
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