Nikon Z 9 Reference Manual page 117

Option
[Subject-
n
tracking AF]
[Auto-area
h
AF]
D
Caution: 3D-Tracking and Subject Tracking
The camera may be unable to track subjects that:
•
are similar in color, brightness, or pattern to the background,
•
change visibly in size, color, or brightness,
•
are too large or too small,
•
are too bright or too dark,
•
move quickly, or
•
are obscured by other objects or leave the frame.
•
Track focus on a selected subject.
•
Position the reticle over the target and start
tracking by pressing the shutter-release button
halfway or by pressing the J or AF-ON; the focus
point will track the selected subject as it moves
through the frame. To end tracking and restore the
starting focus point, press J .
•
This option is only available in video mode.
•
The camera automatically detects the subject and
selects the focus area.
•
Use on occasions when you don't have time to
select the focus point yourself, for portraits, or for
snapshots and other spur-of-the-moment photos.
Description
Focus
117