Nikon D810 - Manual (Page 344)

320
Choose how long the monitor remains
on when no operations are performed
during playback (Playback; defaults to
10 s) and image review (Image review;
defaults to 4 s), when menus (Menus;
defaults to 1 minute) or information
(Information display; defaults to 10 s)
are displayed, or during live view and movie recording (Live
view; defaults to 10 minutes). Choose a shorter monitor-off
delay for longer battery life.
c4: Monitor off Delay
G
button ➜ A Custom Settings menu