Bracketing
|
|
This article discusses a concept in photography. For the literary device of the same name, see inclusio.
In photography, bracketing is the general technique of taking several shots of the same subject using different settings. Bracketing is useful and often recommended in situations that make it difficult to obtain a satisfactory image with a single shot, especially when a small variation in exposure parameters has a comparatively large effect on the resulting image.
Without further qualifications, the term bracketing refers to exposure bracketing: the photographer chooses to take one picture at a given exposure, one or two brighter, and one or two darker, in order to select the most satisfactory image. Many professional and advanced amateur cameras, including digital cameras, can automatically shoot a bracketed series of pictures. Exposure bracketing is indicated when dealing with high-contrast subjects and/or media with limited dynamic range, such as transparency film or CCD sensors in many digital cameras.
When shooting using print film, the person printing the pictures to paper must not compensate for the deliberately underexposed and overexposed pictures. If you bracket a set of photos but then have them printed using automated equipment, the equipment will assume that the camera or photographer made an error and automatically "correct" the shots it determines are "improperly" done.
Aside from varying exposure, other parameters can be varied in a bracketed series. Focus bracketing is useful in situations with limited depth of field, such as macro photography, where one may want to make a series of exposures with different positions of the focal plane and then choose the one in which the largest portion of the subject is in focus.
White balance bracketing, which is specific to digital photography, provides a way of dealing with mixed lighting by taking several exposures with different white points, often ranging from blueish images to reddish images.
Flash bracketing is a technique of working with electronic flash, especially when used as fill flash in combination with existing light. The amount of light provided by the flash is varied in a bracketed series in order to find the most pleasing combination of ambient light and fill flash.