How to Fix an Underexposed Foreground in Photoshop CS6
Sometimes, editing tools in Photoshop CS6 just don’t cut the mustard when it comes to fixing large areas or foreground of an underexposed image. Instead, you have to use three tools together to repair the damage: a filter, a fill, and a blend mode.
You may have taken at least a couple photos where your subject was lit from behind, thereby underexposing the foreground and burying the subject in the shadows. You can try the Shadows/Highlights adjustment, on the Image→Adjustments menu, which usually does a good job of fixing the problem.
But if you’re not satisfied with that adjustment, you can follow this old-school method. Or you can even go for a combo plate and use them both. Follow these steps to bring your subject back into the light:
Open the image in need of repair.
In the dialog box that appears, name the duplicate file and click OK.
On the duplicate image, choose Image→Mode→Grayscale. Click Discard in the dialog box that appears to discard the color information.
Photoshop has now stripped the color from the image. Don’t worry; this is just an intermediary step.
On the duplicate image, choose Filter→Blur→Gaussian Blur. In the Gaussian Blur dialog box, enter a radius value and click OK.
For a low-resolution image (72 ppi), a value of 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.
Return to the original image and choose Select→Load Selection.
In the Load Selection dialog box, make sure the Document drop-down menu (pop-up menu on the Mac) shows your file from Step 2.
Select Gray for the Channel. Select the Invert box. In the Operation area, leave the setting as New Selection. Click OK to load the selection.
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.
In the Fill dialog box that appears, select 50% Gray from the Use drop-down menu (pop-up menu on the Mac). Select Color Dodge from the Mode drop-down menu (pop-up menu on the Mac). 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.
You can now see the subject of your image in a better light.