Nikon D780 Reference Manual page 531

3
C : Choose the flash control
mode.
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)
4
f : Group the remote flash units.
•
Choose a group (A–F) for each of the remote flash units.
•
The master flash can control up to 18 flash units in any
combination.
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
485