Alright, so we have seen the RGB channels and also the LAB channels. Now, let's take a look at something for all you print professionals out there. We are going to take a look at the CMYK channels.

So I am going to go up and I am going to convert this image to CMYK by choosing Image, Mode, CMYK and when I do that, you are going to notice probably somewhat of a color shift on this image and that is because of the fact that this is not a lossless transition between RGB and CMYK. You are going to notice some color shifting because what you see on the screen is not going to be what actually comes out of your printing device.

Those of you who are in the printing industry, you know exactly what I am talking about and what we are going to do now is we are going to take a look at all of these channels over here. For instance, you have your Cyan channel here, you have your Magenta channel, you have your Yellow channel and your Black channel. Now, these are going to look a little bit different because they merge together a little bit different than the other channels do and they are going to look a little bit different because of the fact that you are working inside of the CMYK mode and that is the mode that's used for printing and it's just going to look, just a little bit off. The blacks aren't going to be as rich and everything is like that because of the color shifts.

Now, this is a great instance for using your channels in color because if you view your channels in color while you are in CMYK mode, you have the ability to see these channels as if they were color separations that you were going to use on your print output device. So I am going to go ahead and I am going to use Command+K or Ctr+K to bring up my Preferences dialog box again.

Go ahead then and I will click on the Interface tab and we will just say Show Channels in Color. When I go ahead and click OK there, you are going to see that we had the Cyan, the Magenta, there is the Yellow and there is the Black. So this is exactly what you would see if you were to output these two separations. So this is tremendously helpful for those of you who are in the printing industry to take these images and break them down as far as color by color goes, so that you have a better understanding of exactly what colors are lying where in your image and so forth.

So if you are using this mode to view the channels here, you are not necessarily going to be changing luminosity values or judging things from masking and things like that. But this is very helpful for those of you who are preparing files for output. So CMYK is generally not a mode that you work on when you are doing image editing, it's usually kind of a finishing mechanism that you use before you go out to print. So viewing channels in this mode is actually okay, and I will recommend that you do that simply because it gives you a better understanding of exactly how these colors interact with one another and how they are overlaid and composited to create your CMYK composite image like you see here.

So what we are going to do now is we are going to go ahead and we are going to convert these back to the regular Black and White channels here. I am going to use Command+K or Ctr+K. I am going to go back into the Interface tab and I am going to turn off Show Channels in Color, just so we can break these down a little bit more. Go ahead and hit OK there and what we are going to do is we are going to take a look at some of these channels and how they interact with one another. For instance, if I click on the Cyan channel here, you are going to see that there is not a whole lot of Cyan in her face.

That's because Cyan generally does not lie inside of flesh tones as we know much the same way the Blue channel and the RGB image did not lie in the flesh tones either. That's why that was significantly darker in that RGB channel that we were viewing earlier. So what we are going to do is we are going to combine this with the Magenta channel by clicking here, and you will notice that by combining those two channels together, we get a better view of the reds that are going to be popping up in this image because as we know, these channels are subtractive and they mash together to create colors based on all of the different colors in the image. So they are not just independent like red, green and blue. All of these colors are dependent on one another to create that CMYK composite that we view there. So once we combine those two together, we are starting to get a little bit better idea of the skin tones because we are mashing in the Magenta which is where a lot of the skin tone information resides.

Also, we are going to click on the Yellow information here which is really going to bring back a lot of the skin tones there and essentially, what we have here is we have all of the colors that are represented in this image besides black and what black is going to do is, it's just going to deeply saturate the dark areas and really extenuate the color value. So essentially you have all of the color information that you are going to have with this image. You are just subtracting out that Black value right now so that it looks a little bit washed out.

So Black really is not a color that mixes to create any other color. Your basic channels that do that are Cyan, Magenta and Yellow. When you add Black in, as I am going to do right now, I am just going to click right there on Black to add that in. You see there that it just over saturates those Black areas and really extenuates those color values. They have not really changed from the previous colors as you are seeing there. They just look different because we have darkened in those black areas and really brought up the shadow values of this image as well.

So like I said, this is a great color mode to work in when you are going for a print output device. This is great for commercial printing things like that, probably not a good idea when you are going out to an inkjet printer or something like that because inkjet printers usually think in terms of RGB and then they convert them out for the CMYK output. So not a good mode to go out to your regular Desktop printer. But if you are going to have a photograph commercially printed or if you are working for a magazine or things like that, this is a great mode to be in and also viewing these channels in color. It's going to give you a little bit better understanding of exactly where all your colors lie and exactly how they are going to interact with one another to create this composite image that you see here on your screen.