Af On; Face/Eye Af Set - Sony a9 II Help Manual

AF On

You can focus without pressing the shutter button halfway down. The
settings for the focus mode dial will be applied.
Press the AF-ON (AF On) button while shooting in autofocus
mode.
Hint
• Set [ AF w/ shutter] to [Off] when you do not want to perform auto
focusing using the shutter button.
• Set [ AF w/ shutter], [
a specific shooting distance predicting the position of the subject.

Face/Eye AF Set.

This function is used to determine whether or not the camera will focus
with priority on faces or eyes.
There are two ways to perform [Eye AF]. For details, refer to the
"Help Guide."
• Focusing on the eyes by pressing the shutter button halfway down.
• Focusing on the eyes by pressing the custom key. For details on using
the custom key to perform [Eye AF], refer to page 58.
MENU 
setting item.
Face/Eye Priority in AF: Sets whether or not to detect faces or eyes inside
the focusing area and focus on the eyes (Eye AF) when autofocus is
activated. ([On]/[Off])
(Note: The camera operations are different when using the custom key
to execute [Eye AF].)
Subject Detection: Selects the target to be detected.
[Human]: Detects human faces/eyes.
[Animal]: Detects animal eyes. Animal faces are not detected.
GB
56
Pre-AF], and [
(Camera Settings 1)  [Face/Eye AF Set.]  desired
Eye-Start AF] to [Off] to focus at