Autobracketing is a feature of some more advanced

camera A camera is an instrument used to capture and store images and videos, either digitally via an electronic image sensor, or chemically via a light-sensitive material such as photographic film. As a pivotal technology in the fields of photograp ...

s, whether

film A film, also known as a movie or motion picture, is a work of visual art that simulates experiences and otherwise communicates ideas, stories, perceptions, emotions, or atmosphere through the use of moving images that are generally, sinc ...

digital camera A digital camera, also called a digicam, is a camera that captures photographs in Digital data storage, digital memory. Most cameras produced today are digital, largely replacing those that capture images on photographic film or film stock. Dig ...

s, particularly

single-lens reflex camera In photography, a single-lens reflex camera (SLR) is a type of camera that uses a mirror and prism system to allow photographers to view through the lens and see exactly what will be captured. SLRs became the dominant design for professional a ...

s, where the camera will take several successive shots (often three) with slightly different settings. The images may be automatically combined, for example into one high-dynamic-range image, or they may be stored separately so the best-looking pictures can be picked later from the batch. When the photographer achieves the same result by changing the camera settings between each shot, this is simply called bracketing.

Parameter altered

The bracketing is typically for one specific parameter:

Exposure

Exposure autobracketing (often abbreviated to ''AEB'' for ''automatic exposure bracketing'' or ''BR'' for ''Bracketing'') is the most common form. In this, the camera is set to capture the same image several times with different exposure settings, both over-exposed and under-exposed (lighter and darker) compared to the current setting on the camera, which may already include

exposure compensation Exposure compensation is a technique for adjusting 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. Factors considered may include ...

. Depending on the camera, the difference between each of the autobracketed shots could be anywhere from one-quarter up to three full stops in each direction, in full, half, third or quarter stop increments, ranging from two up to nine shots in series. Sometimes it is possible to either define the order, in which the shots will be taken, or to give an offset as a start-point of the bracketing series. More sophisticated equipment allows auto-exposure bracketing to be combined with timer and

intervalometer An intervalometer, also called an interval meter or interval timer, is a Machine, device that measures short intervals of time. People commonly use such devices to signal, in accurate time intervals, the operation of some other device. The inte ...

functions as well. Cameras can perform autobracketing by adjusting either the

shutter speed In photography, shutter speed or exposure time is the length of time that the film or digital sensor inside the camera is exposed to light (that is, when the camera's shutter (photography), shutter is open) when taking a photograph. The am ...

(typically in

aperture priority Aperture priority, often abbreviated ''A'' or ''Av'' (for aperture value) on a camera mode dial, is a mode on some cameras that allows the user to set a specific aperture value (f-number) while the camera selects a shutter speed to match it that ...

mode, sometimes also in manual or program mode) or the

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

setting (typically in

shutter priority Shutter priority (usually denoted as S on the mode dial), also called time value (abbreviated as Tv), refers to a setting on cameras that allows the user to choose a specific shutter speed while the camera adjusts the aperture to ensure correct ...

mode). In programmed exposure mode, many cameras will alter both parameters at the same time. Some cameras allow to swap the parameter used for shifting in manual mode. Digital cameras may also alter the ISO setting if auto-ISO is enabled. Exposure autobracketing is most commonly used with color reversal film (slide film) because of its small exposure latitude compared with print film (which has a wide exposure latitude) and digital cameras (which enable the photographer to review the captured image). In digital photography, autobracketing is convenient to shoot pictures for

high-dynamic-range imaging High dynamic range (HDR), also known as wide dynamic range, extended dynamic range, or expanded dynamic range, is a signal with a higher dynamic range than usual. The term is often used in discussing the dynamic ranges of images, videos, audio or ...

Flash

Automatic flash bracketing (sometimes abbreviated to ''FBR'' for ''flash bracketing'' or ''FEB'' for ''flash exposure bracketing'') is typically performed by altering the flash output of a connected dedicated flash accordingly. Using non-dedicated studio flashes, for example on the PC socket, flash bracketing can be carried out by altering the aperture, however, this will also affect ambient light and the

depth of field The depth of field (DOF) is the distance between the nearest and the farthest objects that are in acceptably sharp focus (optics), focus in an image captured with a camera. See also the closely related depth of focus. Factors affecting depth ...

. If, in manual mode, a camera defaults to alter the shutter speed, it might be necessary to swap the parameters used for shifting in order for the camera to alter the aperture instead. Since the flash may need time to recharge between the shots, some cameras fall back to single-advance drive mode during auto flash bracketing, even if they are otherwise configured for continuous-advance drive.

ISO

Automatic ISO bracketing simulates exposure bracketing by altering the ISO or signal gain prior to conversion of the image to JPEG or other image file format. The actual exposure values (aperture and shutter speed) are usually kept constant. Auto ISO bracketing is not a common feature of digital cameras.

White-balance

Another common form of autobracketing is

white balance In photography and image processing, color balance is the global adjustment of the intensities of the colors (typically red, green, and blue primary colors). An important goal of this adjustment is to render specific colors – particularly neu ...

autobracketing (sometimes abbreviated to ''WBB'' for ''white balance bracketing''); this applies only to digital cameras, not to film cameras. This function provides a way of dealing with mixed lighting by having the camera take one shot and process the raw sensor data several times for slightly different white point settings, with both higher and lower

color temperature Color temperature is a parameter describing the color of a visible light source by comparing it to the color of light emitted by an idealized opaque, non-reflective body. The temperature of the ideal emitter that matches the color most clos ...

s (bluer and redder) compared to the current setting on the camera. Typically, the amount of offset can be configured. Since shooting in a camera's raw format (if supported) the white balance can be arbitrarily changed in postprocessing as well at a later stage, white balance bracketing is particularly useful for reviewing different white balance settings in the field.

Focus

Depth of field

The

Minolta Maxxum 7 The Minolta A-mount camera system was a line of photographic equipment from Minolta introduced in 1985 with the world's first integrated autofocus system in the camera body with interchangeable lenses. The system used a lens mount called A-mo ...

's STF function is an automatically calculated and pre-compensated seven-fold multi-exposure with depth-of-field bracketing which emulates the smooth

bokeh In photography, bokeh ( or ; ) is the aesthetic quality of the blur produced in out-of-focus parts of an image, whether foreground or background or both. It is created by using a wide aperture lens. Some photographers incorrectly restr ...

effect of Smooth Trans Focus.

Dual-bracketing

Some cameras which provide bracketing of two parameters at the same time.

Notes

References

{{Reflist

External links

Auto exposure bracketing explained and examples of how it is used
Camera features Photographic techniques