Join Mark Christiansen for an in-depth discussion in this video Begin a color key with a g-matte, part of After Effects Compositing: 4 Color Keying.
- Most green screen foreground scenes don't…make use of the entire frame…and so it can be helpful to start with what…is most commonly called a garbage mat or G Mat for short.…The process is also known as Rig Removal.…The basic idea here is to mask out the areas…of the background that are useless to the foreground…because the subject never crosses them.…So in this scene we can see that although we've…got some movement by our talent…it's all covered by this popup green screen,…and so at the very least we want to get rid…of all of the scenery that was behind him.…
Now we're gonna be able to take care of a lot of it.…Just using a simple rectangle mask.…So I'll start with that and you can see that I need…to make some additions and subtractions to it.…So I can just do that with the pen tool.…By adding a point down here I can pull the corner in…but I'm gonna do it right where his elbow crosses.…How bout right there!…And I'm just gonna be careful to both add and drag it.…A little tricky to do so if I just add it and then drag it…
Author
Mark Christiansen
Released
12/7/2014Beginning with a brief explanation of the keying process, Mark takes you through the steps involved in creating a perfect green-screen key: generating a rough matte, eliminating color spill and matte lines, and refining problematic edges. He shows how to work with Keylight and Primatte—two indispensable keying tools in After Effects—and explains when to use one over the other. And for times when green screen won't work, he shows how to generate high-contrast mattes, or luma keys, based on the luminance data in your footage. Last, learn about compression and how to prep a shot for keying.
- What is color keying?
- Using garbage mattes
- Getting started with Keylight
- Understanding the Screen Color, Clip Black, and Clip White adjustments
- Eliminating spill with Advanced Spill Suppressor
- Using Key Cleaner to refine edges automatically
- Dividing a matte with holdout mattes
- Breaking down a complex color key
- Creating a luma key with Extract
- Setting up sky replacement
- Using Refine Soft Matte to improve edge detail
- Feathering edges with Channel Blur
- Knowing when to avoid green screen
- Prepping a shot for keying
Skill Level Intermediate
Duration
Views
Q: How do I locate the exercise files for chapter 5, 6, and 7 of this course?
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Introduction
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Welcome1m 50s
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Using the exercise files2m 23s
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1. Work with Keylight
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2. Manage Edges and Spill
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3. Divide a Matte for Best Results When Keying
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Add a holdout matte1m 38s
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4. Solve Problematic Edges
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5. Complex Color Keys and Primatte
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6. High-Contrast Mattes (When There Is No Green Screen)
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7. Prep for Success When Color Keying
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Prep a shot for keying3m 4s
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Video: Begin a color key with a g-matte