Canon EOS-1D X Mark III DSLR Camera (Body Only) - Manual (Page 846)

Rec card, img size setting
As the display used when the < > button is pressed to select a card or set the image size,
you can specify the rear LCD panel or the screen.
: Rear LCD panel
After pressing the < > button, you can watch the rear LCD panel while turning the
< > or < > dial.
: Screen
Pressing the < > button displays the [ Img type/size ] or [ Record func+card/folder
sel. ] screen (or [ Movie rec quality ] screen in movie recording), and then each press of
the button switches between these two screens.
OFF: Disable button
Disables the < > button for card selection or setting image size. This can prevent
unintended changes to the selected card or image size if the < > button is pressed
accidentally. Use menu screens to select cards or set the image size.
846