See how to produce high-quality keys that fit well within their new scenes, while retaining the subtle details that make the results believable, in After Effects.
- Hi, I'm Mark Christiansen. You can't see me right now because advanced green-screen technology has made me completely invisible. Color keying is the most common way to create basic movie magic. By shooting actors against a particular shade of green or blue, you can place them into any scene, real or fabricated. You probably associate this technique with big-budget affects movies, but in reality, it's just as accessible as the equipment you use to make your own movies. (grunts) Color keying is computer automated, but the best shots require more than just a one button solution.
It needs knowledge and a little bit of finesse and that's what I offer you in this course. We'll focus on the most common issues that can leave your shot looking like this. There are a number of words that we've come up with over the years to describe this type of edge: clumpy, chewy, sizzly. Whatever word you use, the edges around the hair are completely destroyed and even smooth surfaces like the arm look really horrible. Or this. Matte lines. These nasty, dark borders around the edges of the foreground that are the classic giveaway of a keyed shot.
When they could look like this: Soft, natural edges, so full of detail that you believe this foreground belongs with this background even if the lighting match could use a little work. Or you can transform this, not only messy, green spill, but heavy background noise. Or this: heavy foreground noise, as well as matte holes that are often the result of trying to preserve delicate edges. Into this: a matte that appears natural and believable, even in a stylized shot like this.
So now, let's get started making movie magic.
Beginning 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