Gradient Map
The Image > Adjustments > Gradient Map (Figure 10.93) does a rather simple and unusual thing: It first converts an image to grayscale, and then replaces the shades of gray in the image with different colors that show up in a gradient. When you first get into the dialog box, it will default to a black and white gradient, which should just make your image look grayscale. Then, if you click on the down-pointing arrow to the right of the gradient preview, you'll be able to choose a preset gradient to replace the shades of gray that were in the original image (Figures 10.94 and 10.95). If you'd prefer to bypass the preset gradients and create your own gradient, you can click in the middle of the gradient preview to access the gradient editor. If you'd like to know how to create your own gradients, be sure to read the information about the Gradient tool in Chapter 1, “Tool and Palette Primer.”
Figure 10.93. The Gradient Map dialog box.
Figure 10.94. The original image. (©2005 Stockbyte, www.stockbyte.com)
The main problem with using the Gradient Map command is that you can easily end up with bright colors across the full range of the image, which will trash the contrast of your image (Figure 10.96). To prevent that, choose Layer > New Adjustment Layer > Gradient Map. When prompted, set the Mode pop-up menu to Color, and then click OK to get to the Gradient Map dialog box. Because the adjustment layer you just created is using the Color blending mode, it will be able to change only the colors in your image, and will not be able to mess with the brightness (Figure 10.97).
Figure 10.96. The contrast of the image has changed radically.
Figure 10.97. Using the Color blending mode prevents the Gradient Map from messing up the contrast of the image.
I often use the Gradient Map command to transform a backlit image into one that looks like it was taken at sunset (Figures 10.98 and 10.99). All you have to do is create a gradient that starts with black and slowly fades to orange and then yellow (Figure 10.100). If you want to turn the image into more of a silhouetted image, then just slide the black color swatch in the gradient editor toward the right until you no longer see much detail in the subject of the photo (Figure 10.101).
Figure 10.98. The original image. (©2005 Stockbyte, www.stockbyte.com)
Figure 10.99. The result of applying a black, orange, yellow gradient map.
Figure 10.100. The three-color gradient used to create Figure 10.99.
Figure 10.101. The result of dragging the black slider toward the middle of the gradient.
