Canon EOS-1D X Mark III DSLR Camera (Body Only) - Manual (Page 867)

: Switch to Registered AF Point
Pressing the button assigned to this function during metering enables you to switch to the
registered AF point.
* 3: To select [ Switch only when btn is held ] or [ Switch each time btn is pressed ], press the
< > button when the setting screen is displayed. For instructions on registering AF points,
see Registering the AF Point .
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