Sony ILCE-9 a9 Help Manual page 407

Help Guide
Interchangeable Lens Digital Camera
ILCE-9
α9
Pre-AF (still image)
The product automatically adjusts focus before you press the shutter button halfway down.
MENU → (Camera Settings1) → [ Pre-AF] → desired setting.
1
Menu item details
On:
Adjusts focus before you press the shutter button halfway down.
Off:
Does not adjust focus before you press the shutter button halfway down.
Note
[ Pre-AF] is available only when an E-mount lens is mounted.
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