Canon EOS-1DX Af Setting Manualbook page 50

How to set the AF area selection mode
After pressing the
is pressed, the [AF area selection mode] changes. By
setting the menu [AF4] tab's [AF area selection method]
to [ -> Main Dial], after pressing the
can switch the mode with the Main Dial if you prefer.
Press the
The mode is changed each time
the
button, each time the
button
button is pressed
50
button
button, you