A common retouching task is removing red-eye—that devilish effect that appears when a camera flash reflects off the retina. Ideally, you'll avoid red-eye by using off-camera flash, but if your (or someone else's) photograph already has red-eye, you'll have to remove the red. The Red-Eye tool (sharing a slot on the Tools panel with the healing brushes and the Patch tool) is by far the easiest way of doing so, but sometimes it removes the eye color too, so I still resort to the following techniques when necessary.
Hue/Saturation. Select the offending pupils with an oval marquee, feather the selection by a few pixels, copy the selection to a new layer (Command-J in Mac OS X, Ctrl-J in Windows), and then use Hue/Saturation to shift the color, brightness, and saturation. Every image requires different values, but you might want to start with Hue at +40 (for brown eyes) or -120 (for blue eyes), Saturation at -75, and a Lightness value of -50. The key is to remove the glaring color while still maintaining the specular highlights and color that make the eye look alive.
Color Replacement Tool. The Color Replacement tool lets you change the color of pixels to the foreground color but leave the pixels' saturation and brightness alone. In other words, it changes the color but retains the detail. It's less effective on large areas, but it's quite good at fixing things like red-eye. Hold down the Option key (Mac OS X) or Alt key (Windows) and click on the darkest part of the eye (or some other dark area nearby), then let go of the Option/Alt key, adjust the brush size to slightly smaller than the pupil, and draw over the red portions. You may need to increase the Tolerance level in the Options bar to 35 or 40 percent.
The Vanishing Point filter makes editing in perspective orders of magnitude easier than it used to be. Vanishing Point is a very deep plug-in, and if you plan to use it a lot, read about the filter in the online Photoshop Help file and master the considerable number of options and keyboard shortcuts.
Defining the Planes. To open Vanishing Point, choose Filter > Vanishing Point or press Command-Option-V (Mac OS X) or Ctrl-Alt-V (Windows). The first step in using Vanishing Point is to define a perspective plane by clicking on four points, and then to enlarge the plane to cover the area you want to affect (see Figure 11-20). Watch the color and size of the grid when dragging its corners or sides: Red means the grid is not valid perspective, yellow is pretty close, and blue is good. In general, it's better to see a grid of bigger squares than smaller rectangles. Sometimes moving the grid corners by a pixel or two will make a big difference in the quality of the perspective.
Figure 11-20 Cloning in perspective in the Vanishing Point filter