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Preview histogram adjustments

You can preview the effect on the histogram of any color and tonal adjustments.

 Select the Preview option in the dialog boxes of any color or tonal adjustment command.

When Preview is selected, the Histogram panel shows how the adjustment affects the histogram.

Note: When making adjustments using the Adjustments panel, changes are automatically reflected in the Histogram panel.
Preview of histogram adjustment in the Histogram panel

A.
Original histogram

B.
Adjusted histogram

C.
Shadows

D.
Midtones

E.
Highlights