MOTION
The idea in photographing most action subjects
(see Sports) is to use a shutter speed that's fast
enough to stop any hint of motion. There are times,
though, when intentionally switching to a slow shutter
speed and exaggerating subject movement better interprets
its true essence. A race horse frozen in mid-stride is not
nearly as expressive of action as one whose four legs are
tangled in a rhythmic blur.
One way to capture action in motion is by keeping the
camera steady and letting the movement write its own
story across the frame. In photographing a rush-hour
crowd, for example, standing in one place and using a
long exposure will turn the onslaught into a swirling array
of faceless forms. As with stopping action, the actual
shutter speed you use will depend on three factors: the
speed of your subject, its direction, and how close it is. As
a starting point, estimate the correct shutter speed for
stopping action and then experiment with shutter speeds at
least two times slower; typically speeds in the 1/30- to
1/4-second range are effective.
In the technique called panning, you use a slow shutter
speed and move the camera to follow your subject. The
result is a relatively sharp subject surrounded by a blurred
or streaked background. With a moderately slow shutter
speed (1/60 or slower), focus on your subject (a skier, say)
and gently press the shutter as you pan with it. It helps if
there's a good color contrast between subject and
background. Panning is one technique for which a point-
and-shoot has an advantage, because you can continue to
see your subject during the exposure. With an SLR, once
you press the shutter, the reflex mirror will block your
view.
Occasionally you may be the one in motion--trying to
shoot pictures from a moving cable car, for example. In
these situations stopping action (not to mention camera-
shake) is near impossible, and it's often better simply to go
with the flow, slow down the shutter speed, and let some
blur into your pictures.