Nikon Z 8 Reference Manual page 118

D
Locking Focus When AF-S Is Selected for Focus Mode
Focus locks while the shutter-release button is pressed halfway. You can also lock focus by pressing the
center of the sub-selector.
D
Taking Multiple Shots at the Same Focus Distance
If you locked focus by pressing the center of the sub-selector, focus will remain locked between
shots if you keep the center of the sub-selector pressed.
If you locked focus by pressing the shutter-release button halfway, focus will remain locked if you
keep the button pressed halfway between shots.
Tip: Locking Focus with the AF‑ON Button
The AF‑ON button can be used for focus in place of the shutter-release button.
When [AF‑ON only] is selected for Custom Setting a6 [AF activation], focus can be initiated only
by pressing the AF‑ON button; the camera will not focus when the shutter-release button is pressed
halfway. Focus locks after the AF‑ON button is released. To end focus lock, press the AF‑ON button
again.
118
Focus