Brightness and Contrast adjustment

Apply this adjustment via the Adjustment button on the Layers panel or via Layer > New Adjustment.

The following settings can be adjusted in the dialog:

Brightness—controls the lightness/darkness of the image. Drag the slider to the left to decrease brightness, drag to the right to increase it.
Contrast—controls the tonal range of the image. Drag the slider to the left to decrease the contrast between dark and light areas, drag to the right to increase it.
Linear—by default, the adjustment prevents shadow and highlight clipping by modifying pixels relative to their original lightness value. When selected, this option modifies pixels using absolute values and clipping may occur.