Nikon D750 DSLR Camera (Body Only) - Manual (Page 235)

207
A
Exposure Bracketing
The camera modifies exposure by varying shutter speed and aperture
(mode
P ), aperture (mode S ), or shutter speed (modes A and M ). If On is
selected for ISO sensitivity settings > Auto ISO sensitivity control
( 0 136) in modes P , S , and A , the camera will automatically vary ISO
sensitivity for optimum exposure when the limits of the camera
exposure system are exceeded; in mode
M , the camera will first use
auto ISO sensitivity control to bring exposure as close as possible to
the optimum and then bracket this exposure by varying shutter speed.