Nikon D750 DSLR Camera (Body Only) - Manual (Page 216)

188
Flash compensation is used to alter flash output by from –3EV to
+1EV in increments of
1 /
3
EV, changing the brightness of the main
subject relative to the background. Flash output can be
increased to make the main subject appear brighter, or reduced
to prevent unwanted highlights or reflections.
Press the M ( Y ) button and rotate the sub-command dial until
the desired value is displayed in the control panel, viewfinder, or
information display. In general, choose positive values to make
the main subject brighter, negative values to make it darker.
Flash Compensation
(P, S, A, M, and h Modes Only)
M ( Y ) button Sub-command dial
Control panel Information display
±0 EV
( M ( Y ) button pressed)
–0.3 (– 1 /
3
) EV +1.0 EV