Join Mark Christiansen for an in-depth discussion in this video Using the exercise files, part of After Effects Compositing 04: Color Keying.
- Here's a quick overview of the file formats that we're using in this course and how to work with them. All of the examples are going to start with a pre made project that you can open up that will match the example file that you see me going through on screen. These are all of the source files that we're using and I'll just drag them in to talk a little bit about them. With the project panel highlighted if I hit the tilde key it opens up all the information about these files. If I go down the list you'll see that a lot of the source files are in trillions of colors up here at the top.
So to accommodate these higher bit depth source files I've boosted my project to 16 bits per channel and that's what you'll see for the most part in all of these examples. If you don't see 16 you could always change the bit depth by holding option on a Mac or alt on Windows and just clicking to change the bit depth. So 16 is suitable when you're working with a trillions of colors file. In certain cases we have lower bit depth source and that's usually to prove a point.
So here are some eight bit files, it's a single image that's been converted different ways to show how the different ones key. And here we have a comparison between the source that is in trillions of colors with no appreciable compression, and this version that looks the same but actually has h264 compression on it. We'll get into much more detail about that later in the course. So to follow along with the projects just grab the folder containing the project files along with the source folder and move them all to a location on your local drive and they all should link up.
If they don't just right click on a missing file and say "Replace footage" locate the source file, in this case it's already linked but I'll just relink it anyway. And it will be relinked along with any adjacent files that are found in that same folder. There's one third party tool that we're going to use in this course and that's Primatte Keyer from REDGIANT software. Now if you don't own Primatte you can download the trial version and use it for the purposes of the course and if you like it you can invest in it either as a stand alone tool or as part of the keying suite.
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