Adjust the values in the shadows and highlights, and the overall tonal range.
Settings
Apply this adjustment via the Adjustments panel using the following settings:
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.
Opacity—sets the level of visibility of the adjustment.
Linear—by default, the adjustment provides a smooth, logarithmic adjustment by modifying pixels relative to their original lightness value. When selected, this option modifies pixels using absolute values, resulting in a stronger effect.
Delete—closes the settings and deletes the adjustment layer, removing the adjustment.
Merge—merges the current adjustment layer with the layer immediately below it in the layer order.