Nikon Z9 Mirrorless Camera - Manual (Page 51)

51 Parts of the Camera
• Press the M button to cycle through the displays as follows.
[ Automatic display switch ]: The camera automatically
switches between the viewfinder and monitor displays
based on information from the eye sensor.
[ Viewfinder only ]: The monitor remains blank. The
viewfinder is used for shooting, menus, and playback.
[ Monitor only ]: The monitor is used for shooting, menus,
and playback. The viewfinder display will remain blank even
if you put your eye to the viewfinder.
[ Prioritize viewfinder ]: The camera functions in a manner
similar to existing digital SLR cameras.
During photo mode, placing your eye to the viewfinder
turns the viewfinder on; the monitor remains off after you
take your eye away.