Nikon D300 - Manual (Page 294)

268
U
a2: AF-S Priority Selection
This option controls whether
photographs can be taken only
when the camera is in focus (focus
priority) or whenever the shutter-
release button is pressed (release
priority) in single-servo AF. To
select single-servo AF, rotate the
focus mode selector to S.
Regardless of the option selected, focus will lock while the in-focus
indicator (
I ) is displayed.
Option Description
G Release
Photos can be taken whenever the shutter-release
button is pressed.
F
Focus
(default) Photos can only be taken when the in-focus indicator
(
I) is displayed.
Focus mode selector