Fixing an Underexposed Foreground with Photoshop

Sometimes editing tools just don’t cut the mustard when it comes to fixing large areas of an underexposed image. Instead, you have to use three tools together to repair the damage: a filter, a fill, and a blend mode. If you’re like me, you’ve taken at least a couple of photos where your subject was lit from behind, thereby underexposing the foreground and burying the subject in the shadows. Here’s how to bring your subject back into the light:
1. Open the image in need of repair.
2. Choose Image-->Duplicate.
3. Name the file “Repair” and click OK in the dialog box.
4. Select Image-->Mode-->Grayscale.
Photoshop has now stripped the color from the image. Don’t worry; this is just an intermediary step.
5. On the duplicate image, choose Filter-->Blur-->Gaussian Blur. Enter a radius value and click OK.
For a low resolution image (72 ppi), 5 pixels is enough. For higher resolution images (300 ppi), use 20 pixels. Your goal is to get rid of the detail in the image. My image was 170 ppi, so I used 12 pixels to do the job.
6. Return to the original image. Choose Select-->Load Selection.
Under Document make sure it says Repair.
7. Choose Gray for the Channel. Select the Invert box. In the Operation area, leave the setting as New Selection. Click OK to load the Load Selection dialog box.
You’re loading the only available channel in the duplicate grayscale image as a selection. A selection outline appears, which corresponds to the blurry gray areas in your duplicate image.
8. Choose Edit➪Fill. Select 50% Gray from the Use pop-up menu under Contents. Select Color Dodge from the Mode pop-up menu. Leave the Opacity at 100%. Click OK.
Although Photoshop fills the selection with 50 percent gray, the Color Dodge mode lightens the pixels in the image, creating a kind of bleaching effect.
9. You can now see the subject of your image in a better light.