Nikon D780 Reference Manual page 543

3
C : Adjust flash settings.
•
Choose the flash control mode and
flash level for the master flash and
the flash units in each group:
Option
TTL
q A
M
–– (off)
•
Choose a channel for the master
flash. If the remote flash units
include an SB-500, you must choose
channel 3, but otherwise you can
choose any channel between 1 and
4.
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.
i-TTL flash control.
Auto aperture (available only with compatible flash
units).
Choose the flash level manually.
The units do not fire and the flash level cannot be
adjusted.
Description
Remote Flash Photography
497