Getting started with Keylight

If we look at our project, you'll notice we have a piece of green screen footage that already has a garbage mask applied and a graphic background that we want this footage to exist on top of. So the next thing we can do is actually generate a green screen key. Now the effect I like to use for this most is Keylight. So let's select Layer 1, go up to Effect > Keying > Keylight 1.2. When you look at Keylight, sometimes the first time it might seem a little overwhelming.

I'm just going to take you through the key areas that I use about 90% of the time to generate successful keys. The first thing I want you to pay attention to is the Screen Colour. If you click on the Eyedropper to the right of the Color Well, you can click in the green area. When I clicked, if you zoom up to a 100 % magnification and use the Spacebar to move around in the scene, you can see I have some noise here. As I key, I will constantly zoom out and zoom in just so I can see exactly what I'm working with at 100% magnification and compare it to the wide version.

Also another thing that we'll toggle a lot is this View option. So let's go up there right now in the Keylight filter at the top, click on the pulldown menu where it says Final Result, let's go to Screen Matte. Now Screen Matte shows me the result of the key that I've generated. After you sample your green color, if you click and drag on the Gain, you can control exactly how much of that green you want to add or how little. So this is looking at the variance from the sample color, so if we crank this up a little bit, here let's do around 104, that's sampling more variable versions of the green.

Now to look at the result, let's look at Final Result. If we scrub the Balance here, you can see here I'm getting the dreaded color bleed where it goes up in the people's skin tone and things like that. So a lot of times, I'll leave the Balance alone until I go through these next steps. Let's go ahead and undo, Command+Z. So let's change the View from Final Result to Screen Matte. The reason I want to look directly at the Screen Matte, that's usually the next area I go to.

So if we go down to the Screen Matte group and open its options, the first two options are probably the most important. The first one, Clip Black. If you move around the scene just by holding the Spacebar and panning around, you might see a little bit of noise. It's probably hard to see, but I can see a little bit here. So I'm going to click and drag on the Clip Black area, and notice if I drag it too far, it starts clipping up into my mask, which is not what I want. Let's set this to a number around 4, just a very small amount of clip.

Now Clipping White will help deal with the white areas in here. So let's click and drag this down, and as I drag down, it's clipping more of the gray pixels until it gets to the black area, so we could set this around 83. Okay, now let's look at the final result. We go up to the View and change Final Result here in the Keylight. Now let's scroll out and look at our scene.

Let's actually load up a RAM Preview. I'm going to press 0 on my keypad to load that up and let's just load up a few seconds and then press the Spacebar so it can roll through. Okay, this is looking relatively okay, but if we stop playback here, notice she looks a little washed out in comparison to this heavily saturated background. So a lot of times I'll end up doing color correction to the footage after it's keyed. If we collapse the Screen Matte area, go down to Foreground Color Correction, expand its options, and scroll here and then enable our Color Correction.

When we enable that, we can make some tweaks to our final results. So here, I'm liking the Saturation, I just want to up the Contrast a little bit. So a lot of times with Keying, I find if you just click and drag on a parameter, you can scrub until you get a result that you like. Now I tend to like my images a little punchy, so I'm going to bring the Contrast up to around 10. Now as I'm doing that, I'm noticing the saturation of her skin tone is getting a little much, a little unrealistic, so I'll bring the Saturation down just a tiny bit.

And like I said, you can drag with these to your individual taste. This is what I like. If we scroll up to 100% magnification and kind of scrub through here in the timeline, you can see I've got this sort of light edge. So it's not uncommon that I go from the Foreground Color Correction to the Edge Color Correction. So let's expand the Edge Color Correction group and enable Edge Color Correction. Now I'm looking at this and this is a light color, so I'm going to start by just adjusting the brightness down.

So if you click on the Brightness and drag it down, as I'm dragging, you may get a downsample of the Adaptive Resolution. That's okay. When you let go of your mouse, it will pop back up in terms of resolution. Now let's toggle the results. If I disable and re-enable, you can see I've definitely cleaned up the edges of my key just by using Edge Color Correction. To recap, if I zoom out in my scene here, you can see I have a pretty decent key.

And that was created by going through a rather simple processing Keylight to get started. First, you sample the color, adjust the Screen Gain, and then jump down into the Screen Matte area where you can click the Black and White levels while looking at the Screen Matte version of the view. Once you're set with that, you can go back to your Final Result and then make your adjustments with your Foreground and Edge Color Correction. It just so happens that I did all of my color correction within Keylight, which is part of the reason why I love using Keylight, but that does not mean you can't go back up to the Effects Controls and look at some of these other options under Key or Matte to make adjustments to your key or the matte we created by pulling the key with Keylight.