You can choose the operation used to initiate autofocus and set the exposure.
You can choose to initiate autofocus and set the exposure only using the button to which the [AEL/AFL] function is assigned, or control in combination with shutter button operation. This setting can be made for each ［AF Mode］ option.
When using continuous AF ［C-AF］ with ［mode3］ or ［mode4］ selected for [AEL/AFL］ > ［C-AF］, you can perform so-called "thumb-operated AF" where the camera tracks the subject while the AEL/AFL button is held down and shoots when the shutter button is pressed.
When ［Operative] is selected for [AEL/AFL］ > ［Half Way AF］, autofocus can also be initiated by pressing the shutter button halfway. In addition, you can choose to use either the button to which the [AEL/AFL] function is assigned or the shutter button to detect and focus on faces, or to use both buttons.