The Shadows/Highlights command lets you restore detail, breathe life into shadows, and tame highlights. Even though it’s grouped with color correction features, it’s actually a filter. If you’ve ever tried to use it in its default configuration, you’ve probably found the results to be less than satisfactory. In this tip, we’ll look at how to unleash the power of this extremely useful filter.

This tip comes from Chapter 17, “Shadows, Highlights, and Contours,” of Photoshop CS5 One-on-One: Advanced from the lynda.com Online Training Library. The chapter also discusses automatic lens correction, sharpening on top of a blur, smoothing with High Pass, and other techniques for adjusting shadows, highlights, and contours.

Like all filters, Shadows/Highlights directly alters the pixels in a layer. As such, it’s best to apply the command to a copy of your background layer, or to a stamped composite layer.

• To “jump” the background layer: You can duplicate the background layer by clicking on it and using Alt + Ctrl + J (Option + Command + J on Mac) to duplicate the layer via the New Layer dialog. -or-
• To stamp a layer: Click to select the topmost layer first, hold down the Alt (Option on Mac) key and select Layers > Merge Visible from the menu bar or Merge Visible from the fly-out menu at the upper right corner of the Layers panel.

Once you’ve prepared a layer to apply the command, click to select it and choose Image > Adjustments > Shadows Highlights from the menu bar. The Shadows/Highlights dialog will appear.

In its default configuration, the dialog tends to produce underwhelming results—it opens the shadows, does nothing to the highlights, and tends to produce significant haloes around edges. With the interface boiled down to two amount sliders, the default dialog has limited usefulness. Check the Show More Options box to gain more control. As long as the box remains checked, the dialog will continue to open in its expanded mode. Now, you’re ready to apply the command to its fullest potential.

1. First, you’ll want to set the Color Correction adjustment to zero. The adjustment boosts saturation, often in an exaggerated and unpleasant way. You can apply saturation through the Vibrance and Hue/Saturation adjustments, so there’s really no reason to do it in this dialog.
2. Leave the Black Clip and White Clip values set to their defaults. We’ll return to discuss Midtone Contrast later.
3. In most cases, you’ll also leave the Tonal Width for both Shadows and Highlights set to 50%. If you do change the values, they should add up to 100% or less. Otherwise, the effects of the two controls will overlap for some tonal values, and that can be a problem.

You’ll do the majority of the work in this dialog with the Amount and Radius sliders, while the Midtone Contrast setting can provide some additional nuance.

4. Adjust the Amount sliders to taste. Increasing the Shadows Amount opens (lightens) the shadows, while increasing the Highlights Amount reduces the intensity of the highlights. Be careful with the shadows, though; opening the shadows too much will bring out lots of noise.
5. Increasing the Radius value reduces haloes and flares by spreading them across a larger area. The trick is to balance the halo reduction against loss of detail in nooks and crannies, since showing more detail requires a lower Radius.
6. As you work, Toggle the preview checkbox on and off to A/B your results.
7. Click in the Midtone Contrast box and use the Shift + Up Arrow or Down Arrow to bump the value in increments of 10; using the arrow keys alone nudges the adjustment in increments of 1.
8. Once you are happy with the Midtone Contrast settings, readjusting the Highlights Radius may further improve the image.

One thing to keep in mind is that the Shadows/Highlights command is resolution dependent. That means you’ll use different radius settings, based upon the size of your image. Another thing to be aware of, is that the command often sharpens skin, making pores and other skin imperfections pop. Other videos in the chapter discuss techniques such as smoothing with High Pass (you read that right) to correct for these effects.

As you continue to work with the dialog, you may find that you return to similar settings for most of the images that you work with. You can click Save as Defaults to make those settings your starting point whenever you open the dialog. The figure below shows some recommended defaults, which you can season to taste.

One final example: Most of the settings are the same as the first example, but the higlights in this example are not reduced as much. It’s a subtle effect that brings out detail on the inside of her hood and gives her hair a bit more definition, while adding some sculptural structure to her face.