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Quick Tip: Quick Keying in After Effects


Need to quickly key out your green screen work? Just follow these easy steps.

Great green screen work is more about lighting than anything else. While you may have the world’s best keying software at your disposal, if your footage was sloppily shot, there’s only so much that After Effects can do.

Let’s take a look at how to quickly color key footage in After Effects. This post is meant to be just a quick tip… there’s a lot more that goes into get great color keys, but if you need a quick color key, this technique will work.

1. Place Your Green Screen Footage Over Your Background

Quick Tip: Quick Keying in After Effects - Step 1

Place your green screen footage over your background footage in an After Effects composition. Some people prefer to use a bright background, as it’s easier to spot key imperfections on a solid background like red, but it all depends on your own preference. For the purposes of our tutorial, we’re just going to place the footage directly on top of the background.

2. Mask Out Garbage Areas

Quick Tip: Quick Keying in After Effects - Step 2

With your footage selected, select the pen tool (G) and cut out any extra areas that aren’t keyable in your footage. Simply draw a shape around your subject and close the mask by selecting the first mask point.

3. Apply the Keylight Effect to Your Footage

Quick Tip: Quick Keying in After Effects - Step 3

In the effects browser, search for the Keylight effect. Simply drag the effect to your footage in the composition timeline.

4. Use the Eye Dropper to Select Your Color

Quick Tip: Quick Keying in After Effects - Step 4

Select the eyedropper button in the Keylight effect and select a green portion of your green screen.

5. Change the Dropdown Menu to Combine Matte

Quick Tip: Quick Keying in After Effects - Step 5

In the dropdown menu next to the word View in the Keylight effect, change the setting from Final Result to Combine Matte. This will allow you to better see your color key. Keyed-out pixels will be black. Visible pixels will be white.

6. Adjust Settings Under Screen Matte

Quick Tip: Quick Keying in After Effects - Step 6

Now it’s time to start refining your color key. In the dropdown menu titled Screen Matte, you will see a few adjustable settings. Here are a few tips for adjusting them:

  • Bump up ‘Clip Black’ to help get rid of shadow noise, but don’t push it much further than 15.
  • Decrease ‘Clip White’, by a few points, not much less than 85.
  • Adjust ‘Screen Shrink/Grow’ only if necessary.
  • Bring ‘Screen Despot White’ up just a little, 0 – 5 should be great. Just keep an eye on your subjects edges.

We could get really deep into what each of these settings do, but for the purposes of this quick tip, we’ll skip an explanation for now. If you want to learn more about color keying, I recommend checking out Keying Fundamentals in Adobe After Effects over at PremiumBeat.

7. Change The ‘View’ Menu to ‘Final Result’

Quick Tip: Quick Keying in After Effects - Step 7

Once your subject is solid white with no grey noise, change the View Menu from Combine Matte to Final Result.

8. Adjust Transform Properties and Stylize

Quick Tip: Quick Keying in After Effects - Step 8

Now you can begin to focus on compositing your subject into the background. Because After Effects renders the effects in order, you can still apply color correction adjustments to your subject without the affecting your key.

One of my favorite methods for compositing green screen subjects is using the RGB channel compositing method outlined in this tutorial from Sean Frangella.