■1.0-3.0 fps. You can set Continuous L mode to use a relatively pokey frame rate,
too. Use these rates when you just want to be able to take pictures quickly, and aren’t
interested in filling up your memory card with mostly duplicated images. At 1 fps
you can hold down the shutter release and fire away, or ease up when you want to
pause. At higher frame rates, by the time you’ve decided to stop shooting, you may
have taken an extra three or four shots that you really don’t want. Slow frame rates
are good for bracketing, too. Set the D7000 to take a three-frame bracket burst,
and you can take all three with one press of the shutter release. You’ll find that slower
frame rates also come in handy for subjects that are moving around in interesting
ways (photographic models come to mind) but don’t change their looks or poses
quickly enough to merit a 6 fps burst.
A Tiny Slice of Time
Exposures that seem impossibly brief can reveal a world we didn’t know existed. In the
1930s, Dr. Harold Edgerton, a professor of electrical engineering at MIT, pioneered
high-speed photography using a repeating electronic flash unit he patented called the
stroboscope. As the inventor of the electronic flash, he popularized its use to freeze objects
in motion, and you’ve probably seen his photographs of bullets piercing balloons and
drops of milk forming a coronet-shaped splash.
Electronic flash freezes action by virtue of its extremely short duration—as brief as
1/50,000th second or less. Although the D7000’s built-in flash unit can give you these
ultra-quick glimpses of moving subjects, an external flash, such as one of the Nikon
Speedlights, offers even more versatility. You can read more about using electronic flash
to stop action in Chapter 12.
Of course, the D7000 is fully capable of immobilizing all but the fastest movement
using only its shutter speeds, which range all the way up to an astonishing 1/8,000th
second. Indeed, you’ll rarely have need for such a brief shutter speed in ordinary shoot-
ing. (For the record, I don’t believe I’ve ever used a shutter speed of 1/8,000th second.)
But if you wanted to use an aperture of f/1.8 at ISO 200 outdoors in bright sunlight,
for some reason, a shutter speed of 1/8,000th second would more than do the job. You’d
need a faster shutter speed only if you moved the ISO setting to a higher sensitivity (but
why would you do that?). Under less than full sunlight, 1/8,000th second is more than
fast enough for any conditions you’re likely to encounter.
Most sports action can be frozen at 1/2,000th second or slower, and for many sports a
slower shutter speed is actually preferable—for example, to allow the wheels of a racing
automobile or motorcycle, or the rotors on a helicopter to blur realistically, as shown in
Figure 7.2. At top, a 1/1,000th second shutter speed effectively stopped the rotors of
the helicopter, making it look like a crash was impending. At bottom, I used a slower
1/250th second shutter speed to allow enough blur to make this a true action picture.
David Busch’s Nikon D7000 Guide to Digital SLR Photography182