Nikon D850 Menu Manual page 223

4
f: Set the remote flash units to the same channel as the
master flash.
Set the remote flash units to the channel selected in Step 3.
5
f: Group the remote flash units.
Choose a group (A, B, or C, or if you are using an SB-500
master flash, A or B) for each remote flash unit. Although
there is no limit on the number of remote flash units that may
be used, the practical maximum is three per group. With
more than this number, the light emitted by the remote flash
units will interfere with performance.
6
C/f: Compose the shot.
Compose the shot and arrange the flash units. See the
documentation provided with the flash units for more
information. After arranging the units, press the test buttons
on the flash units to test-fire the flash and confirm that the
units are functioning normally. Flash units can also be test
fired by pressing the i button in the flash info display (0 243)
and selecting M Test flash.
7
C/f: Frame the photograph, focus, and shoot.
Optional Flash Units
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