Shadows/Highlights

Shadows/Highlights is a decent alternative to Curves for correcting dark, backlit images, which are often caused by the light source being positioned behind the forefront object in a photo. Shadows/ Highlights can also be used to correct images that contain overly bright highlights, which are often caused by the photographer using a flash setting that is set too high. As a designer, I’m sure you’ve been forced to work with the occasional poorly lit image (okay, maybe more than occasional), and in the old days of Photoshop, the only way to correct them was to become a Curves expert (still a very good idea, by the way). But when Photoshop introduced the Shadows/Highlights feature in the first version of CS, it made this task faster and easier. Although technically not as accurate as Curves, Shadows/Highlights still does a pretty darn good job of enhancing horribly lit photos and making them suitable for print. Before explain the Shadows/Highlights dialog box, I should first mention that this adjustment is available only under the Image ➢Adjustments submenu and not as an adjustment layer—a major downside to using this tool (adjustment layers offer more flexibility and control, because they allow you to make changes to the adjustment any time after it is applied). However, in CS3 you can now apply a Shadows/Highlights adjustment to a smart object in the same way that you can apply filters to smart objects. The other downside to Shadows/Highlights is that in order to adjust a specific area of an image, you must first make a selection before accessing the dialog—something you do not have to do with Curves. To apply a Shadows/Highlights adjustment, open a poorly lit image and choose Image --> Adjustments --> Shadow/Highlight. To really make the most of this tool, select the Show More Options check box at the bottom of the dialog. This expands the dialog to display additional settings. Also, make sure the Preview check box is selected in order to see your adjustments applied as you make them.

By default, the Amount setting in the Shadows area is set to 50%—which, depending on your image, could be a radical adjustment. The first thing to do is set that value down to 0%. Now you can preview your image without any adjustments made and better determine what needs to be fixed. To brighten a dark image, move the Amount setting in the Shadows area to the right until the hidden detail starts to appear. The next step is to set the Tonal Width for the Shadows adjustment. The Tonal Width slider controls the brightness range that is affected in your image. Lower settings limit the adjustment to the darkest areas of the image; higher settings let the adjustment creep into the image’s brighter areas.

After you’ve defined the brightness range that you’re adjusting with the Tonal Width setting, you can then set the Radius amount. The Radius setting determines the amount of surrounding image area that Photoshop should include when blending in the adjustments you’ve made. Moving the Radius slider to the right causes the areas that you’ve adjusted to blend in more with the surrounding image area; moving it to the left creates more contrast between the shadows and midtones. For an example of how the Shadows sliders can be used to lighten an image. The Shadow settings that were used helped lighten the shadows and reveal detail, but the image still lacks contrast. To correct this, contrast must be finetuned in the areas of the image that haven’t changed (the midtones). You can increase contrast by moving the Midtone Contrast slider to the right. Finally, now that the brightness and contrast have both been corrected, the image could use some color saturation. This can be done by increasing the Color Correction value. To correct an overly bright image, move the Amount slider in the Highlights area of the dialog to the right. Doing so darkens the brightest areas of the image. After the preferred darkness amount is set, use the Tonal Width, Radius, Midtone Contrast, and  Color Correction sliders in exactly the same way as you would when correcting a dark image.