Canon EOS-1D X Mark III Advanced User's Manual page 865

: Select AF Point,
During metering, you can select an AF point directly with the <
< > button. Setting this function switches the functions of the <
You can set exposure compensation or the aperture value by holding down the <
button and turning the <
* 6: To set the direction for switching AF points with the <
the setting screen is displayed. [Horizontal] and [Vertical] settings for [Direction: AF point
switching] apply to Spot AF, 1-point AF, Expand AF area: (manual selection), and Expand AF
area: Surround, and [Cycle through the zones], [Horizontal], and [Vertical] settings for
[Direction: Zone AF frame switch] apply to Zone AF.
( During Met)
> dial.
865
> dial without pressing the
> and <
> dial, press the <
> buttons.
>
> button when