Canon EOS 5D Mark III Instruction Manual (en)

By changing the shutter speed or aperture automatically, the camera 
brackets the exposure up to ±3 stops in 1/3-stop increments for three 
successive shots. This is called AEB. 
* AEB stands for Auto Exposure Bracketing.
Select [Expo.comp./AEB].
Under the [z2] tab, select [Expo.
], then press <
Set the AEB range.
Turn the <6> dial to set the AEB 
range. If you turn <5>, you can set 
the exposure compensation.
Press <
0> to set it.
When you exit the menu, <h> and the AEB 
range will be displayed on the LCD panel.
Take the picture.
The three bracketed shots will be taken 
according to the drive mode set in this 
sequence: Standard exposure, decreased 
exposure, and increased exposure.
AEB will not be automatically 
canceled. To cancel AEB, follow step 
2 to turn off the AEB range display.
 Auto Exposure Bracketing (AEB)N
AEB range
During AEB shooting, <A> and <h> will blink respectively in the 
viewfinder and on the LCD panel.
If the drive mode is set to <u> or <B>, press the shutter button three times for 
each shot. When <o>, <i>, or <M> is set and you hold down the shutter 
button completely, the three bracketed shots will be taken continuously and the 
camera will automatically stop shooting. When <
Q> or <k> is set, the three 
bracketed shots will be taken continuously after a 10-sec. or 2-sec. delay.
You can set AEB in combination with exposure compensation.
If the AEB range exceeds ±3 stops, the end of the exposure level indicator will display <I> or <J>.
AEB cannot be set for bulb exposures or used with flash.
AEB will be canceled automatically when you set the power switch to 
<2> or when the flash is ready to fire.