Exposure Compensation - Nikon D6 Reference Manual

Exposure Compensation

Exposure compensation is used to alter exposure from the value
suggested by the camera. It can be used to make pictures
brighter or darker. It is most effective when used with [Spot
metering] or [Center-weighted metering] ( 0 178).
−1 EV No exposure +1 EV
compensation
199
Exposure-Related Settings (Metering and Exposure Compensation)