What are bracketed photo?

What are bracketed photos?
To photograph a high contrast scene, you need to take several exposures in order to capture information in both the highlights and the shadows of the scene. Photos of the same scene taken under several exposures are usually called "bracketed" photos, in reference to the Automatic Exposure Bracketing function available on DSLR cameras.
The number of photos you need depends on the scene. It also depends on the Exposure Value (EV) spacing separating the photos. If you take them in one-EV steps (e.g., -1, 0, +1 EV), you will need more photos than if you take them in two-EV steps (e.g., -2, 0, +2 EV). We recommend shooting in two-EV steps whenever possible.
For most landscapes and other types of outdoor scenes, three exposures taken in two-EV steps (i.e. -2, 0 +2 EV), or five exposures taken in one-EV steps, are usually sufficient.
Camera set up