Photoshop CC: The Missing Manual, 2nd Edition

The Channels Panel and You

To peek inside a channel, open the Channels panel (Figure 5-2)—its tab is lurking in the Layers panel group on the right side of your screen. (If you don’t see it, choose Window→Channels.) This panel looks and works like the Layers panel, which you learned about in Chapter 3.

When you single-click a channel in the panel, Photoshop highlights it to let you know it’s active and temporarily turns off the other channels (see Figure 5-2); anything you do from that point on affects only the active channel. This is extremely useful when you want to, say, blur only the red channel in order to soften skin (since this channel usually has the least amount of texture in it). To activate more than one channel at a time, Shift-click each one (handy for sharpening two channels at once, as shown in Figure 5-15).

Figure 5-2. The Channels panel is your gateway to the color info that makes up your image. The composite channel at the top of the panel (here, it’s the one labeled RGB) shows what your image looks like with all the channels turned on; if you’ve temporarily turned some off, click this channel to turn them all back on. You can’t turn off every channel—at least one has to be visible in order for you to see your image! The little number to the right of each channel’s name is its keyboard shortcut. These shortcuts changed way back in CS4, but if you’d like to revert to ...