Problem : Solution Restore color to underexposed areas

Problem: Photograph is underexposed causing loss of detail.

Solution: Use the History Brush tool to restore detail and clarity.

If you've ever examined an underexposed photograph, you might be tempted to eliminate it without much thought. Unless, of course, you had reason to believe that hiding behind all of that darkness was image detail and clarityand, yes, colorthat would make this photo a "keeper," because you could actually uncover this image information without the laborious process of masking. This is exactly what you can do with the History Brush tool.

Select the shadow areas

This technique works best when only a portion of a photo is underexposed, as shown in our Problem image. To begin:

1.	Open an image with underexposed areas.
2.	Choose Select Color Range to use the Color Range tool.
3.	Choose Shadows from the Select dropdown list in the Color Range dialog box to mask the shadow areas quickly.
4.	Click OK.
5.	Select Edit Fill to begin using the fill command to brighten the shadow areas.
6.	Select 50% Gray from the Use dropdown list in the resulting dialog box and then choose Color Dodge from the Mode dropdown list.
7.	Set the Opacity to 100%.
8.	Click OK.

Once you've applied the Color Dodge fill, the shadow areas of your image should be considerably brighter. In fact, they may look too bright, but that's okay because we'll blend them with the original image later on.

Take a snapshot

1.	Display the History palette, if it isn't already visible.
2.	Click the Create Nve a snapshot of the photo in its current state.
3.	Restore the photo to its original condition by selecting the original state in the History palette.
4.	Click on the box to the left of the new snapshot to define it as the source for the History Brush.

Note

You'll lose all of your snapshots and history states if you close and re-open the file, so be sure to do all of the retouching work we describe in a single Photoshop session.

Paint in the details

Now we're ready to enhance the original image.

1.	Select the Hist brush tool
Choose a brush size appropriate to your image, and adjust the hardness to 0% to give it fuzzy edges.
3.	Set the opacity to 50%.
4.	Paint over the shadow areas you want to lighten using the History Brush tool. The result is similar to shining a light on the affected area. To ensure a smooth blend, hold down the mouse button until you finish brightening each section of the image. Photoshop only applies the lightening effect once in any given area until you release the mouse button. If a particular area doesn't brighten as much as you'd like, click on the same area and paint over it a second time.

Color when and where you need it

While you can produce a similar color enhancement using the Shadow/Highlight tool (introduced in Photoshop CS), the technique we describe in this article allows you to apply the enhancement selectively and gives you more control over the results. It also functions in older versions of Photoshop and in color modes, such as CMYK, where some adjustment tools don't work.