Lighten or darken a photo

Lighten or darken a photo using the Levels dialog box.

You can lighten or darken a photo using the Levels dialog box. The Levels dialog box displays a graph, called a histogram, which depicts the tonal range of an image. Images with poor tonal ranges, such as underexposed and overexposed images, result in fairly low and flat histograms. On the other hand, an image with a good range of darks and lights generates a deeper, more varied histogram. Using the histogram as a guide, you can adjust the tonal balance of an image.

In the Layers palette, select the layer containing the image you want to change.

Choose Image > Adjustments > Levels. Arrange the Levels dialog box so that the you can see as much of the image as possible.

In the Levels dialog box, drag the black Input Level slider (on the left of the histogram) so that it aligns with the leftmost cluster of pixels in the histogram. This maps the darkest pixels in the image to black. (If the pixels are clustered on the left edge of the histogram, you don't need to move the black Input Level slider.)

Drag the white Input Level slider so that it aligns with the last cluster of pixels on the right end of the histogram. This maps the lightest pixels in the image to white. (If the pixels are clustered on the right edge of the histogram, you don't need to move the white Input Level slider.)

Drag the gray Input Level slider either to the left to lighten the image or to the right to darken the image. Although this seems counterintuitive, by moving the gray slider to the left, for example, you map the midtones of the image to a darker shade while increasing the range of the light tones.

When you are satisfied with the image, click OK.

You can make all color adjustments on an adjustment layer, rather than directly to the image. Isolating your adjustments on a separate layer lets you experiment with the image without altering its actual pixels. Because the settings are on a separate layer, you can view the image with and without the adjustment by clicking the adjustment layer's eye icon . To create an adjustment layer, choose Layer > New Adjustment Layer > Levels.