Canon EOS-1D X Mark III Advanced User's Manual page 232

2.
Set the AEB range.
(1) AEB amount
(2) AEB range
Turn the <
3.
Take the picture.
Standard exposure Decreased exposure Increased exposure
Three bracketed shots are taken, according to the specified drive
mode, in this sequence: Standard exposure, decreased exposure, and
increased exposure.
AEB will not be automatically canceled. To cancel AEB, follow step 2 to
set the AEB amount to "0.0."
> or < > dial to set the AEB range.
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