Nikon D780 DSLR Camera (Body Only) - Manual (Page 506)

460 On-Camera Flash Photography
Follow the steps below to mount an optional flash unit on the
camera and take photographs using the flash.
1
Mount the unit on the accessory
shoe.
See the manual provided with the unit for
details.
2
Turn on the camera and flash unit.
The flash will begin charging; the flash-ready indicator ( c )
will be displayed in the viewfinder when charging is
complete.
3
Adjust flash settings.
Choose the flash control mode ( 0 463) and flash mode
( 0 465).
Using an On-Camera Flash