Under a bracketing is understood in photography a graded series of exposures to Convey the object scope of the bill or of a subject as precisely as possible the printing range of a photographic material or cast. This same motif is repeated several times imaged at different exposure settings (eg / - a half or thirds f-stop ). Brackets can be used both when photographing themselves as well as during the creation of magnifications in the photo lab.
Changing the exposure is carried out either for the duration of the exposure time is controlled or on the photographic aperture.
Modern electronically controlled cameras can create bracketing to usually three, five or seven pictures automatically. This is usually referred to by the English term Auto Exposure Bracketing ( AEB).
Examples from practice
Bracket is possible both on the camera side during recording and later in the positive development.
Slide films have a much lower latitude than negative film; therefore it needs to be exposed much more precise. When in doubt, bracketing is recommended when high contrast.
Also in digital photography are bracketing advisable when it comes to complex lighting conditions that occur in far more situations than many amateurs guessed. In many cases, this is also recommended the change from automatic to manual exposure. An example of this stage shots where the disturbing influence of the numerous point lights - namely, the headlights, the flashes and lights from other photographers, etc. - with cutout or changes in perspective makes a reasonably uniform exposure about a series of photographs of the main subject when using an automatic almost impossible.
In the traditional photo lab bracketing be used and evaluated, among other things, in the form of test strips.
In the reprophotography bracketing are created to obtain at least one reproduction that matches the original as closely as possible. This is necessary because on the one hand the exposure is not always one hundred percent results in accurate results due to such factors as the extract extension or filters used, on the other hand, because the graphic arts films commonly used to work extremely hard.
A night scene on conventional film, the exact exposure time can not be accurately determined because of the Schwarzschild effect under certain circumstances. Here you can also reach a useful result by trial and error using a bracketing.
A bracketing in combination with appropriate software can help to improve the over negative film lower contrast range of digital photos and to expand. Here, from the ( unbewegten! ) motif is a bracketing created so that each part of the subject is well reproduced on at least one of the images in the series. Subsequently, a so-called HDR image can be created on the computer from the individual images, which has an extremely large range of contrast (see HDRI generation of bracketing ).
Flash bracketing FEB ( )
Under a flash bracketing, Eng. February ( Flash Exposure Bracketing ) refers to gradations in terms of flash intensity. Similar to the exposure time also can be made for higher-quality cameras and flash units corrections.
White balance bracketing ( WBB )
Some digital cameras also have the function of a white balance bracketing. Here, a plurality of images are taken with a balance of different color temperatures while maintaining the same exposure time. The English term for this is White Balance Bracketing, short WBB.