Bracketing

In photography, bracketing is the general technique of taking several shots of the same subject using different camera settings, typically with the aim of combining the images in postprocessing.

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.

This closely resembles the Bokeh-pleasing optical effect of the apodization filter in the Minolta/Sony STF 135 mm f/2.8 [T4.5]'s special-purpose lens.

Usually this involves the use of software with unsharp masking, a filtering algorithm that removes out-of-focus portions of each exposure.

The brightness levels in this case are only altered by increasing or decreasing gain, or amplification of the digital signal prior to the conversion to an image file such as a JPEG or Tag Image File Format (TIFF).

This type of bracketing must be performed with the camera in Manual mode but is easy to implement simply by shooting a single properly exposed image in RAW and applying exposure compensation in post processing.

In this case the exposure compensation (EV value) setting remains constant while bracketing the ISO value in Av, TV, or P mode, which will have a corresponding effect on the shutter speed, aperture value, or both.

This form of ISO bracketing could potentially affect not only image noise, but also depth of field and motion blur.

Canon EOS 100 viewfinder information with AEB
A series of images demonstrating a focus bracket. The image on the left shows a single shot taken at f / 10 with the features of the fly closest to the camera. The center image shows the features farthest from the camera. The image on the right shows focus stacking : a sequence of six incrementally focused images of the fly assembled to make a composite image using CombineZM .