Oftentimes I take a photo when the lighting conditions are less than ideal. Maybe there’s too much backlight or the kids insist on standing in the shade when the sun is so bright. The result is that the faces are dark, but the background is light.
There are a number of options for lightening dark shadows on your photos. In Photoshop Elements you can try one of the following:
1. Go to Enhance>Auto Levels. Sometimes the computer is just smart enough to fix it so you like it!
2. Go to Enhance>Adjust Lighting>Shadows/Highlights and play with the lighting by moving the arrow on the sliding bar.
3. Duplicate your photo. In the Layers Palette, select Screen from the pull-down menu. This will lighten the entire image but you can play with the opacity or erase portions of the top layer so that only parts of your image are lightened. Merge the two layers when you’re happy with how it looks.
4. Use the Smart Brush tool to lighten the shadows of a select part of your photo.
More : see this article from the Daily Digi