Bracketing, as you probably know, refers to shooting the same image a few times at different apertures or shutter speeds. Bracket when you can’t tell in advance which exposure setting is absolutely the best.
For example, you may have difficulty predicting the best aperture to use at sunset to best reproduce the bright crimson sky. Your meter indicates an aperture of around f/11. Try bracketing by shooting at f/11, and then shooting the same image a half-stop more open and a half-stop more closed. You may decide to take additional bracketing shots – some even more open and some even more closed.
Or you want to use a slow shutter speed to give the “angel-hair” look to a waterfall. But what shutter speed is best – 1/30…1/15…1/8…or even slower? Since you usually can’t tell in advance, shoot at all three speeds – and more if you can – and select the best image you get back.
Or you may want to shoot a skiing scene in which the snow is reproduced as pure white. If the exposure is even a hair off, the snow will have an off-color tint: it may seem grayish or bluish or some other color. Again, bracket your exposures and pick the processed result in which you get the whitest snow.
Obviously, bracketing is most effective when you use it for a static object like a landscape because you want to get more-or- less the same image in each frame even though the shots are taken a few moments apart. You can’t bracket a wide receiver making a spectacular catch, or one car crashing into another.
What about bracketing with an automated camera or point-and-shoot that doesn’t give you the control of aperture or shutter speed? Sometimes you can “fool” the camera into bracketing. For example, you may be able to bracket by changing “mode” – for example, by shooting once in “Portrait mode” and then again in “Sports mode.” Or you may be able to shoot once without “Backlight Compensation” and once with it. In each case, you will be varying the aperture or shutter speed or both.