GoPro HERO 4 Black User Manual page 68

/ Protune
EXPOSURE VALUE COMPENSATION (EV COMP)
Exposure Value Compensation affects the brightness of your video or
photo. Adjusting this setting can improve image quality when shooting
in environments with contrasting lighting conditions.
Settings
-2.0 -1.5 -1.0
PRO TIP: Exposure Value Compensation adjusts brightness
within the existing ISO Limit. If brightness has already reached the
ISO Limit in a low-light environment, increasing the Exposure Value
Compensation does not have any effect.
RESET
This option resets all Protune settings to their default values.
68
-0.5 0 (default) +0.5 +1.0 +1.5 +2.0