Dodging and Burning by Hand
The powerful one-two punch of adjustment layers and blending modes also comes in handy for those times when specific areas of your image aren’t successfully addressed by overall changes to curves or blending modes. You already saw forms of local corrections back when we masked adjustment layers for edits based on Curves and the Multiply and Screen blending modes. For more free-form control, you can set up a single layer that gives you reversible dodging and burning without having to draw a curve, and it’s possible because of the Overlay blending mode.
If you stayed awake during the descriptions of each blending mode a few pages back, you might remember us talking about a blending mode’s neutral color—the color that doesn’t change the image in that blending mode. For Overlay, the neutral color is 50 percent gray. The useful side effect of a 50 percent gray neutral color is that painting tones lighter than 50 percent gray into the layer lightens an image, and painting tones darker than 50 percent gray darkens the image.
Unlike other techniques in this chapter, this one doesn’t involve an adjustment layer. You create a new pixel layer, but instead of clicking the Create New Layer button in the Layers panel, Option-click (Mac OS X) or Alt-click (Windows) that button so that the New Layer dialog appears with its options (see Figure 8-23). Choose Overlay from the Mode pop-up menu and the “Fill with Overlay-neutral color (50% gray)” check box becomes available—turn it on and click OK. Now use the Brush tool to lighten (paint with white) or darken (paint with black) any areas of the image. Painting pure white or black on a 50 percent gray Overlay layer can produce high-contrast results, so you’ll probably prefer to reduce the opacity value for the brush (in the Options bar) and build up the effect.
Figure 8-23 Dodging and burning using Overlay
At this point you might be asking, “Why not just use the Dodge and Burn tools?” While the Dodge and Burn tools are improved in Photoshop CS4, they are still destructive—you permanently change image pixels. The only way to reverse your changes is with Undo and the History panel, both of which you lose when you close a document. With an Overlay-based dodge-and-burn layer, if you change your mind you can simply paint a different tone on the Overlay layer (or paint 50 percent gray to restore the original image), all without ever altering the pixels of the original image’s layer.
Updated Dodge and Burn Tools in Photoshop CS4. Although we prefer to use the nondestructive Overlay layer method instead of the Dodge and Burn tools in the Tools panel, if you do decide to use these two tools it’s worth mentioning that Adobe has improved them in Photoshop CS4. In previous versions, Dodge and Burn got out of control so easily that they were best used at a very low opacity value, so that you could build them up. In Photoshop CS4, those tools now have a Protect Tones check box in the Options bar that minimizes the chance of color shifts and ugly, clipped tones; we recommend that you leave Protect Tones on. In addition, the Sponge tool (in the same tool group) now has a Vibrance check box in the Options bar that helps avoid extreme saturation or desaturation.