Nikon D780 DSLR Camera (Body Only) - Manual (Page 519)

473 On-Camera Flash Photography
5
Lock flash level.
After confirming that the
flash-ready indicator (
c )
appears in the viewfinder, press the control selected in Step
1. The flash unit will emit a monitor pre-flash to determine
the appropriate flash level. Flash output will be locked at this
level and FV lock icon (
r ) will appear in the viewfinder.
6
Recompose the photograph.
7
Take the photograph.
Press the shutter-release button the rest of the way down to
shoot. If desired, additional pictures can be taken without
releasing FV lock.
8
Release FV lock.
Press the control selected in Step 1 to release FV lock.
Confirm that the FV lock icon (
r ) is no longer displayed in
the viewfinder.