Nikon Z9 Mirrorless Camera - Manual (Page 307)

307 Recorders
D Zoom
• The camera display can be zoomed in by pressing the X button during
recording, but this has no effect on the footage output to the recorder.
• If no footage is currently being recorded, changes to zoom using the X
button will be reflected both in the camera display and in the output to the
recorder. The output resolution however switches to [
1080p
(progressive) ], even if the option last selected for [ HDMI ] > [ Output
resolution ] in the setup menu was [ 4320p (progressive) ] or [ 2160p
(progressive) ].