Section II Shooting
246
from the camera, 1/250 second would be needed
to freeze a diagonal movement. Motion across the
field of view would need 1/500 second. Figure 9-6
is a table comparing the effects of distance and
direction of movement on shutter speeds for some
typical subjects.
Another factor is the distance of the subject
from the camera—the closer the subject, the
faster it will move across the lens’s field of view,
and the faster the shutter speed needed to stop
its motion. The most challenging combination
is a fast-moving subject crossing the camera’s
field of view a few feet in front of the lens. At the
opposite extreme, of course, is a slow-moving
subject coming directly toward the camera, but a
long distance away.
Complicating the issue is the focal length of
the lens you use. As the focal length increases,
the field of view narrows proportionately. If both
a 100 mm lens and a 200 mm lens are focused
on a bicycle rider 100′ away, the bicyclist would
cross the field of view of the 200 mm lens twice as
fast, because the field of view of that lens is only
half as wide. Using a longer lens also requires
a faster shutter speed, since you are in effect
closer to the subject. The shutter speed is doubled
for each doubling of the focal length. If you
selected a shutter speed of 1/125 second to stop
the bicyclist’s motion with the 100 mm lens, you
would have to use a speed of 1/250 second with
the 200 mm lens to achieve the same effect.
Even though today’s most fully featured SLR
cameras offer shutter speeds as brief as 1/8000
second, some action cannot be stopped by shutter
speed alone. In some cases, the movement is too
rapid even for a very fast shutter speed; in others,
low light levels require slower shutter speeds
(even with large apertures) for proper exposure.
Object in motion
(or type of action)
Approximate
speed
Distance
from camera
Type of
movement
(mph) (kph) (feet) (meters)
Toward/
away
Diagonal Across
• People walking 5 8 10–12
25
50
100
4
8
16
33
1/125
1/60
1/30
1/15
1/250
1/125
1/60
1/30
1/500
1/250
1/125
1/60
• People jogging, skating,
or bicycling
• Children in active play
10 16 10–12
25
50
100
4
8
16
33
1/250
1/125
1/60
1/30
1/500
1/250
1/125
1/60
1/1000
1/500
1/250
1/125
• Active sports
• Animals (large) running
• Vehicles on city streets
25 40 10–12
25
50
100
4
8
16
33
1/500
1/250
1/125
1/60
1/1000
1/500
1/250
1/125
1/2000
1/1000
1/500
1/250
• Vehicles on highway 50 80 25
50
100
200
8
16
33
66
1/500
1/250
1/125
1/60
1/1000
1/500
1/250
1/125
1/2000
1/1000
1/500
1/250
• Racing vehicles
• Other fast-moving subjects
100 160 25
50
100
200
8
16
33
66
1/1000
1/500
1/250
1/125
1/2000
1/1000
1/500
1/250
1/4000
1/2000
1/1000
1/500
Figure 9-6. Shutter speeds needed to stop motion for some typical situations.
NOTE: Shutter speeds listed are for 35 mm cameras, based on use of a normal (50 mm) lens. For longer lenses, shutter speeds
must be adjusted upward, moving to the next highest speed for each doubling of the focal length. Thus, 1/500 with a 50 mm lens
increases to 1/1000 for a 100 mm lens, or 1/2000 for a 200 mm lens.