Canon EOS-1DX Af Setting Manualbook page 107

Buttons that can be assigned to
switching AF area selection modes
There are the five buttons that can be assign to switch
AF functions. The
assigned with [Custom Controls] to [Register/apply
shooting functions], and the
can be assigned with [Switch to registered AF functions].
'Register/apply shooting functions' assigns.
AF-ON button
AE lock button
'Switch to registered AF functions' assigns.
lens AF stop button
Multi function2button
depth-of-field preview button
button and
button and
107
button can be
button