c1: Shutter-Release Button AE-L

G button UA Custom Settings menu

Choose whether exposure locks when the shutter-release button is pressed.

Option		Description
O	[On (half press)]	Pressing the shutter-release button halfway locks exposure.
P	[On (burst mode)]	Exposure only locks while the shutter-release button is pressed all the way down.
[Off]		Pressing the shutter-release button does not lock exposure.