This is Part 2 of Things I Learned: Green Screen. These are things I learned from my first time working with green screen. If you missed it, check out Part 1 which covered the setup and the shoot.
Before I started to talking about the post production stuff, it might be nice to show you the final product from my first green screen shoot. So here you go.
My post workflow for this project was definitely unique. Introducing the keying element complicated things a little more than normal. For most projects, I do 95% in Final Cut Pro: importing footage, cutting, audio, and basic grading. If it is needed, I’ll occasionally cleanup or adjust audio with Soundtrack Pro and add titles with After Effects.
At first, I tried to do my keying in FCP. I used the plugin Primatte RT. It did a decent job, but lacked controls for fine tweaking. If quick is what you need, then this might be a good path for you. I ended up waiting to key the footage until I sent my edit to After Effects because I had no Idea how to export a sequnce from FCP with an alpha channel.
The only option out there that I found was either trying some crazy code converting or buying an awesome and expensive plugin called Pro Import AE 5.0 by Automatic Duck. Unfortunately, I’m not going to spend $500 on that. I’d rather buy the new AE CS5 (neither of which I can afford).
Anyway, this meant that I had to export my completed edit from Final Cut Pro as a .MOV file and then use that file to key. Two major downsides: any significant changes meant that I had to edit & re-export from FCP and it meant I had to keyframe a lot more instead of just applying effects to a specific clip.
LESSON #2: The Keylight plugin in After Effects is great! It provides a lot of control over pretty much all the elements of the keying process. This is especially helpful when you have made some mistakes in when shooting the piece (see Part 1 for more details). Below are a couple resources for keying using After Effects that I found helpful.
- Keying with Keylight plugin | Adobe CS3 Video Workshop
- Keying Overview & Tips | Adobe Help Center
- Basic Training: Keying & Transparency | VideoCopilot.com
- Basic Color Keying | VideoCopilot.com
LESSON #3: The order of effects make a huge difference. One thing that I struggle with on this project was getting a clean deep black on the t-shirt. It was rather noisy and not super solid. So, I tried adding the Levels and Brightness & Contrast effects and played with them. I would get it looking good in the preview, but the final export never was quite what I wanted.
One thing that I forgot to consider is the rendering order. When rendering, AE compiles the effects in order from top to bottom. That means that depending on what order you place the effects, it can change your final output. Once I change the order of the effects, I got a much more pleasing black on the t-shirt once it was exported.
Okay, I know that I only wrote about 3 lessons but it’s hard to remember these things when you write an article 3 weeks after you do the project. Next time, I’ll make sure to at least write a few thoughts down as I’m doing the project.
Working with green screen is a lot of fun, however, it can be a bit of work to get things right. I’m sure the next time I do a green screen piece, I’ll learn a few more things too. If you have worked with green screen and have a few tips or resources, I’d love to hear from you!