HDR Photography: Bracketing
Bracketing is taking two or more photographs with different exposures of the same scene at the same time. It's an important step in high dynamic photography.
Back in the day when film was king, bracketing was a way to cover more exposure possibilities (like placing more bets on different numbers at a Roulette wheel — you stand a greater chance of winning). Without digital exposures and auto review, you could only be sure you got the best exposure when the film was developed.
With HDR, bracketing is not about being uncertain of the correct exposure, but rather, increasing the amount of exposure data you’ve gathered.
Bracketing most often assumes that the central exposure is at 0.0 EV but this does not have to be the case.
The word bracket can be used as a verb, as in, I told my assistant to bracket the scene. It can also refer to a single photo in the bracketed set.
A bracketed set is a group of bracketed photos that all go together, as seen in the figure. This is a 5-shot bracketed set, taken at +/- 1.0 EV. You’ll often see people indicate the exposure settings of a bracketed set as -2/-1/0/+1/+2 EV.
See how it all fits together?