Nikon Z 9 Reference Manual page 888

Image quality
JPEG basic
1 Figures are for a ProGrade Digital COBALT 1700R 325GB memory card (as
of September 2021) with a NIKKOR Z 50mm f/1.8S lens mounted on the
camera.
2 Number of pictures that can be saved to memory card or stored in
memory buffer varies with scene recorded.
3 Maximum number of exposures that can be stored in memory buffer at
ISO 100. May drop in some situations, including when:
•
an optimal-compression ([ m ]) JPEG option is selected for [Image
quality] or
•
[ON] is selected for [Auto distortion control].
4 Figures assume a size-priority option (an option not marked with [ m ]) is
selected for [Image quality]. Selecting an optimal-compression ([ m ])
option increases file size; the number of images and buffer capacity drop
accordingly.
Memory Card Capacity
888
Image
size
Large
4
Medium
Small
Number of
File size exposures
remaining
Approx.
39,900 frames
5.3 MB
Approx.
65,200 frames
3.4 MB
Approx.
123,000 frames
1.9 MB
Buffer
2, 3
capacity
2
Over
1000 frames