Nikon Zfc Mirrorless Camera with 28mm Lens - Manual (Page 504)

Flash compensation
504
Flash compensation
Flash compensation is used to deliberately alter flash output, for
example in order to change the brightness of the subject relative to the
background. Via the [Flash compensation] item in the photo shooting
menu, flash output can be increased to make the main subject appear
brighter, reduced to prevent glare, or otherwise fine-tuned to produce
the desired result.
･ Choose from values of from −3 to +1 in steps of 1/3.
･ Higher values make the subject brighter, lower values darker.
･ At values other than ±0.0, a Y icon will appear in the shooting
display.
･ Normal flash output can be restored by setting flash compensation to
±0.0. Flash compensation is not reset when the camera is turned off.