Black and White Photography

Bracket exposures. One popular strategy for dealing with difficult lighting
conditions or with particularly important subjects is to take more than one
exposure at a range of settings. Called bracketing, this technique helps ensure
that you will get at least one correctly exposed negative. First make an initial
exposure at the meter-recommended f-stop and shutter speed. Then make at
least two additional exposures: one to allow more light in and one to allow in
less. This gives you a range of three exposures, one of which is likely to best
capture the scene.
Try bracketing a full stop either way, for a three-shot bracket. For example,
suppose the meter’s suggested settings are f/8 at 1/125. Take your first exposure
at that reading, and then take a second exposure to let in one stop more (twice
as much) light, such as f/5.6 at 1/125 or f/8 at 1/60. Then take a third exposure
letting one stop less (half as much) light in than your initial setting, such as f/11
at 1/125 or f/8 at 1/250. If you want a broader range, make a five-stop bracket
by shooting extra frames two stops either way.
You must ordinarily bracket in manual exposure mode, because in autoexposure
mode the camera will adjust one setting when you change the other.
However, many cameras offer autobracketing in autoexposure mode. When
the camera is set for autobracketing, you press the shutter button once, the
camera takes three different exposures (or more for even broader bracketing, if
you choose) in rapid succession. You can even vary the amount of the bracketed
exposures, usually up to two stops (and in fractional increments) in either
direction.
You also might consider partial bracketing, which involves making extra exposures
in only one direction—usually one at the initial f-stop and shutter
speed, and the other to allow in double the light. So if the meter’s indicated exposure
is f/8 at 1/125, take a picture at that exposure and a second one at f/8 at
1/60 or f/5.6 at 1/125.