By the Book: This article is an excerpt from Skin: The Complete Guide to Digitally Lighting, Photographing, and Retouching Faces and Bodies , by Lee Varis (copyright 2006; reprinted by permission of Wiley Publishing).
The days of airbrushing, dye transfers, spotting, and etching are long gone, but the need to clean up or enhance photographs has never been greater. Portraits in particular can require a certain amount of retouching to flatter the subject. Frequently, this requires only basic cleanup—remove a mole, take out a stray hair, and so on. But other problems, such as uneven skin tones, are less straightforward.
Red, blotchy skin often looks worse in digital images because the Bayer-pattern imaging systems used to interpret cameras’ image data tend to overemphasize the red component in skin color. As a result, pimples and red blotches tend to go nuclear. Fortunately, the problem is relatively simple to fix in Adobe Photoshop ($649) by using a Hue/Saturation adjustment layer. (The following steps also work with Adobe’s $80 Photoshop Elements 4.)
Isolating the problem
Click on the Adjustment Layer icon in the Layers palette and choose Hue/Saturation from the drop-down menu. In the Hue/Saturation dialog box, change the Edit drop-down menu to Reds.
With the left eyedropper toward the bottom of the dialog box selected, move the cursor (the eyedropper sampler) over the image, and click on the brightest red pimple. The sample-region slider (indicated by the gray bars in the rainbow gradient) will move slightly to center over the selected color. Then select the minus-eyedropper tool (on the right) and click on an area of good skin color. The sample region will shrink somewhat to indicate the more constrained sample area.
This part is the trick: we are going to temporarily apply a radical hue shift to help visualize the selected region. Push the Hue slider all the way to the left. The selected reds in the face will turn bright cyan. If too much of the image has been selected, simply drag the right triangle slider in the gray sample region to the left to trim the selection and limit the effect to those areas that are too red and blotchy (see “Spotting the Problem”).
Making the change
After you have identified the region that will be affected, you can employ a more attractive color shift. Drag the Hue slider to the right, past zero and toward yellow. Stop when you’ve killed the red curse.
Use the Info-palette numbers to determine if the skin values in the pimple regions are within the correct range (move the cursor into the image to get a reading). Because pimples are also darker than normal skin, you may need to push the Lightness slider to the right until you get better tonal uniformity. Don’t go too far; it will reduce the saturation of the skin tone and may make your colors look unnatural.
Some areas of the face might be too yellow. You can adjust these areas in a similar fashion. In the Hue/Saturation adjustment-layer dialog box, change the Edit drop-down menu to Yellows. Use the eyedropper tool to select the region that is too yellow; then subtract the red pimple areas with the minus-eyedropper tool (these are now already shifted). Apply the radical hue shift to visualize the affected region, and trim the selection further if necessary. Push the Hue slider slightly to the left to make the yellow regions redder. The Edit drop-down menu, which did say Yellows, will change to Reds-2 to indicate that you are editing another red region.
Once you’re done, you should find that the Hue/ Saturation adjustment has hidden most of the pimples and given the skin a much healthier look—all without your touching a single retouching tool.
You might want to mask off the red to reduce the effect of the Hue/Saturation adjustment on the lips—especially with photos of women. Just paint into the Hue/Saturation adjustment layer with black to mask out the lips. In this image, I also brushed a little blue color into the eyes to relieve some of the monochromatic nature of the shot.
Although you’ve toned down the red, some pimples may still appear darker than the surrounding skin. To carefully lighten these areas without otherwise affecting the color or texture of the region, use a dodge-and-burn layer set to Soft Light mode (see “Dodging Minor Imperfections”).
In the end, all of the pimples have become soft freckles, and we haven’t corrupted the skin texture.Better-Looking Skin: Red, blotchy skin is a common problem in portraits. The skin appears much healthier after a Hue/Saturation adjustment.Spotting the Problem: By shifting the Hue slider all the way to the left, you can quickly see which areas will be affected. Use the Sample Region sliders to select just the problematic red tones.