You can reset the image brightness using the keypad hotkey.
To reset Brightness settings:
Press - (minus sign) on the keypad.
The Brightness slider and Brightness Balance wheel are reset to their default settings. Printer light settings are also reset
and the image reverts to its original printer light settings.
NoteModifications you made to the image using the Brightness controls for shadows, midtones, and highlights are not reset to their
default values. See Resetting Parameters.