Overexposed Images Quick-Fix
The easiest way to fix an overexposed photo is to open it in Photoshop and choose Image> Adjustments> Shadow/Highlight (CS-only. For pre-CS look below). You’ll see an immediate change in your photo and it will probably be too extreme, but just use this setting as a starting point. Photoshop ships with defaults that are often way over the top. Just play with the Amount Slider and the Tonal Width Slider in both the Shadows and the Highlights until you find just the right balance. And that’s it!
Fixing Overexposed Photos, Pre-CS - The Layer Sandwich Trick If you don’t have CS, then this trick will help you accomplish similar results.
Step 1 - New Layer Open your photo and make a copy of the Background Layer by selecting Layer> Duplicate Layer, or by dragging it to the New Layer Icon at the bottom of the Layers palette.
Step 2 - Change the Blend Mode From the Layers palette change the Blend Mode of the new layer from Normal to Multiply. This will darken the photo uniformly.
Step 3 - Repeat Now repeat the entire process again. Create a new layer, change the blend mode to multiply, and watch the result. Continue doing this over and over until you go from “it’s almost just right” to “it’s awful!”
Step 4 - Lower the Opacity Now leave the last layer active even though it is much too extreme and lower the Opacity using the slider at the top right of the layers palette. This lowers the strength of the effect. Once you have found the right amount, you can flatten your image.
Step 5 - Flatten And Save Choose Layer> Flatten or use the palette’s flyout menu and choose Flatten Image. Save your file (File> Save) and that’s it!