Exposure compensation is a technique used in photography to adjust the exposure indicated by a photographic exposure meter, in consideration of factors that may cause the indicated exposure to result in a less-than-optimal image
. It allows photographers to override exposure settings picked by the camera's light meter to darken or brighten images before taking the shot
. Exposure compensation works by adjusting one or more of the exposure variables, depending on what camera mode you are using. For example, in aperture priority mode, exposure compensation works by changing the shutter speed to get the right exposure, while in shutter priority mode, it works by changing the aperture to the right exposure
. Many digital cameras have a display setting and possibly a physical dial whereby the photographer can set the camera to either over or underexpose the subject by up to three f-stops (f-numbers) in 1/3 stop intervals
. Exposure compensation is useful in situations with uneven light distribution, filters, non-standard processing, or intended underexposure or overexposure
