Bracketing

Bracketing is a method for shooting several consecutive exposures of the same scene automatically using different settings, as a way of improving the odds that one of the images will be exactly right for your needs. Before digital and electronic film cameras took over the universe, it was common to bracket exposures, shooting, say, a series of three photos at 1/125th second, but varying the f/stop from f/8 to f/11 to f/16. In practice, smaller than whole-stop increments were used for greater precision. Plus, it was just as common to keep the same aperture and vary the shutter speed, although in the days before electronic shutters, film cameras often had only whole increment shutter speeds available.

Today, cameras like the Alpha can bracket exposures much more precisely. When this feature is activated, the Alpha takes three consecutive photos: one at the metered “correct” exposure, one with less exposure, and one with more exposure, in your choice of 1/3 or 2/3 stop increments. Figure 4.19 shows an image with the metered exposure (center), flanked by exposures of 2/3 stop less (left), and 2/3 stop more (right).