Nikon Z 9 Reference Manual page 509

Option
Choose the shutter speed below which auto ISO sensitivity
control will kick in to prevent underexposure in modes P
and A; options range from
selected, the camera will choose the minimum shutter
speed based on lens focal length. For example, the camera
will automatically choose faster minimum shutter speeds
to prevent blur caused by camera shake when a long lens is
[Minimum
attached.
shutter
•
speed]
•
To view auto shutter-speed selection options, highlight
[Auto] and press 2 . Auto shutter-speed selection can be
fine-tuned by choosing faster or slower minimums.
Faster settings can be used to reduce blur when
photographing fast-moving subjects.
Shutter speeds may drop below the selected minimum if
optimal exposure cannot be achieved at the ISO
sensitivity chosen for [Maximum sensitivity].
Description
1
/ to 30 s. If [Auto] is
16,000
C The Photo Shooting Menu: Shooting Options
509