The Hue/Saturation Dialog Box
Choose Hue/Saturation from the adjustment layer pop-up menu at the bottom of the Layers palette to get started. (The icon looks like a circle, half of which is filled with black.) That will create an adjustment layer, and send you into the Hue/Saturation dialog box (Figure 10.4). You can make three types of changes with this type of an adjustment—changes to Hue, Saturation, and Lightness.
Figure 10.4. The Hue/Saturation dialog box.
If you look at the bottom of the Hue/Saturation dialog box, you'll see two strips of color, which show you all the possible hues you can use in Photoshop. Those color strips are really just a standard color wheel that's been straightened out. The color on the far left is the same as the one on the far right, so you could easily bend it into a circle to make a color wheel. The Hue slider will allow you to change the basic colors that make up your image. Go ahead and open any colorful image and move the Hue slider around to see what happens (Figures 10.5 to 10.7). The top strip of color indicates all the hues that you could possibly have in your image, whereas the bottom bar indicates what you've done to each of the hues. You can pick a color from the top strip and look straight down to the lower strip to figure out what Photoshop has done to it. For now, just remember that hue means basic color, and that the Hue slider will change the basic color of everything in your image. In a little while I'll show you how to get much more control over the specific colors in your image, but first we should look at the other two types of changes we can make with the Hue/Saturation dialog box.
Figure 10.5. The original image. (©2005 PhotoSpin, www.photospin.com)
Figure 10.6. Moving the Hue slider will shift all the hues in your image.
Figure 10.7. The result of applying the adjustment shown in Figure 10.6.
Using the same photo, move the Saturation slider all the way to the left; your image should become completely black and white. Move the slider all the way to the right and all the colors in your image should become ridiculously vivid (Figure 10.8). Most images can use a modest saturation boost; for now that's all I'll say on the subject, but I'll get back to it in a little while.
Figure 10.8. This image is divided in half; the left side shows the original image, and the right side shows what happens when you move the Saturation slider all the way to the right. (©2005 PhotoSpin, www.photospin.com)
The last control is a bit more straightforward than the other two, but you'll have to be very careful when you adjust the Lightness slider. Go ahead and slide it all the way to the left and then all the way to the right to see what happens to your image. You should end up with a solid black image at one extreme and a solid white one at the other. That's a pretty generic adjustment, and can easily mess up your image (especially when applying it to the entire image). It's not quite as bad as using the Brightness and Contrast control (from the Image > Adjustment menu), which brightens or darkens every shade in your image an equal amount, but it's close. This slider will become much more useful once we figure out how to isolate a range of color to adjust.