Channels Palette

About Channels

Photoshop actually looks at an image as a combination of 3 grayscale images (or four if you are working in CYMK mode). One channel represents red, one green, the other blue. The dark areas in each channel are areas with none of the color, light areas contain more color. The red channel in this picture is dark over the sky and water because there is not much red in the sky or water, the sand is light because it contains more red. The blue channel is much lighter than the red channel in the sky and water because they are, obviously, more blue. As you can see, green is kind of in between.

Access the channels through comman-1,2, or 3. Use command-~ to get back to the regular RGB image.

Uses of Channels

• I use them mostly for when I am converting a picture to black and white, often one of the red, green or blue channels look better than the converted grayscale image through the Image>Mode>Grayscale command.
• The blue channel is often very "dirty" with a lot of noise/grain. When trying to clean up an image, you can just work on the blue channel without destroying the info in the other channels.
• When making selections, an object is sometimes more well defined in one of the channels than it is in the color image.