Brightness and contrast adjustment is a good tool to use to perfect the lighting of your photo.

Increasing brightness is the equivalent of adding light to the entire picture. The first picture shows an overly brightened picture to show exaggerated effects.

Contrast, like mid-tone contrast, will simultaneously adjust darks and lights relative to each other. The second picture shows a high contrast setting which has caused the darks to become very deep and the whites to give off a sort of glare.

For this picture, a slight increase in brightness is enough to properly light the object of the picture.