57 Channels and nothing on

Unlike cable television, we have only three channels to view - Red, Green, and Blue - and they each contain useful information. I said before that you really don’t need to know the whys of channels, but knowing how to use them will increase your creative potential. And you do need to memorize three simple concepts:

Red / Cyan

Green / Magenta

Blue / Yellow

That’s pretty much all you need to grasp in order to use channels effectively. Repeat the combinations in your mind, over and over, like a mantra. As anyone familiar with composite editing knows, things are never as simple as my first tutorial would suggest. I did a lot of work on those two photos beforehand, just to ease you into a complex subject (sorry, folks, but it got your attention, didn’t it?). So let’s start with some basics.

Basic color correction
Open the Portrait Man.jpg and immediately make a duplicate (Ctrl+D). Then File>Save As (Ctrl+Shft+S) as Portrait Man Dup.ufo. Make sure both pictures are at 100% magnification (Ctrl+1), because anything less or more will not be the true picture. It’s a temporary resampling done behind the scenes by PI. Under the Window menu choose Tile Vertically. Now we can compare and choose. To open the Tone Map dialog box choose Format>Tone Map, or better yet, learn the keyboard shortcut, Ctrl+Shft+T (you may end up using the Tone Map a lot). Keeping in mind the three concepts above, let’s put them to work.

Make sure the Real Time Preview box is checked in the bottom left corner of the box. In the Channel drop-down menu click on Red. You have two choices of action here. You can add more Red to the picture, or you can remove Red, and by doing so you add Cyan. To demonstrate this, move the Midtone slider far to the right of zero, then move it far to the left of zero. Reset the slider to zero and choose the Green channel from the drop-down. If you memorized the three color combos above, you already know your choices here - add Green or remove Green, therefore adding Magenta. And in the Blue channel, what happens if you remove Blue. Correct. Play around for awhile, then hit the Cancel button.

Let’s analyze this photo for a minute. Computer monitors can vary some, but everyone should see that there is a slight blue color cast. This is common to pictures taken outdoors on a sunless winter day (and it doesn’t help that he’s wearing a blue pullover!) I remember that his beard was more reddish than it appears, and his skin tone didn’t look like the blood had been sucked out of him. It’s an easy fix with channels.

First we need to add some pop to the contrast, and we’ll use the Master channel sliders with which you are probably already familiar. The settings I used were Highlight:20, Midtone:15, and Shadow:-5. You may need to adjust the settings a small amount, but, in any case, it’s an immediate improvement. Click on Red from the Channel drop-down. Move the Midtone slider to the right to 15 (or enter 15 in the numeric box). Hey, he’s alive! Again, monitors vary, as do preferences in flesh tones, but I also went to the Blue channel and moved the Midtone slider to the left at -5. Do you sense the control you have? When you have the overall color as you like it, hit OK.

This wasn’t a photo that needed serious correction, but I’m sure you see the point. If it lacks Red, add it. Too much Blue, take it away. If you want to make someone look like a green man from Mars, feel free to do so. If you are a wizard with your Selection Tools, you can use Channel manipulations on just one part of the image. (A word of warning here: Any color correction used on a selection turns the selection into an object. Why? Another one of Ulead’s merry little pranks, I suppose. It drove me batty till I found out what was going on.)

For my final picture above I used the Lasso tool to make a selection around the pupils of his eyes, softened it 2 pixels, then used the Hue and Saturation dialog with the Colorize radio button selected. You don’t have to do that. Save the picture (Ctrl+S). We’ll use it again. Time to move on to something more challenging.

Go to Part2