Section 1 The Basics
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The denominator, or bottom number, of the
shutter speed fraction should be larger than the
focal length of the lens to decrease the chance for
camera movement. If you are using a 100 mm lens,
for example, your shutter speed should be 1/125
second or higher; with a 300 mm lens, shoot at
1/500 second or faster. There are both physical and
optical reasons for this practice. Physically, longer
focal length lenses extend farther from the camera
and are often heavier than short lenses, making
them harder to hold steady. Optically, you are
dealing with a magnified image of a distant object,
so any movement is exaggerated. See Figure 2-35.
A B
C D
Jack Klasey/Goodheart-Willcox Publisher
Figure 2-34. Additional methods for steadying a camera. A—Using chair arms for support while sitting. B—Placing
elbows on a table or other support surface when sitting, standing, or kneeling. C—Sitting back on your heels and resting
one elbow on the heavy muscle of your thigh, when in a kneeling position. D—Using your chest and elbows as the three
legs of a tripod when lying on your stomach.
Goodheart-Willcox Publisher
Figure 2-35. When a telephoto lens is focused on a
distant object, the slightest movement of the camera is
greatly magnified.
Slight movement
at camera
Movement magnified
by distance to subject