One of the most popular special effects currently used in video production is the green screen: shooting on-camera talent against an evenly lit background and replacing the background in post with something that wasn’t ever there.
Green screen is almost essential for visual effects shots, but even a simple interview or spokesperson stand-up can be livened up with a green screen. Political agencies have gotten very good at shooting green screen. Their turnaround has to be quick, so they have no time to waste fixing problems in post.
I can calculate the amount of green screen footage I’ve keyed in months, not minutes, and have developed some tips for producers looking venture into the verde painlessly.
1. Don-t scrimp on money for the shoot – Use a shooter and/or lighting person who has done green screen before. The dollars you save trying to DIY or hire the inexperienced will be burned in the post production process trying to get the key to work.
2. Shoot either in full resolution or at a higher resolution than the final product – Many of today’s formats work solely on compressing the video – cheating on the amount of little dots in the TV frame in order to get more information on a drive or disk. This compression can kill a perfectly usable green screen. So if your final product will be standard def, shoot Dbeta. If you’re finishing with standard def, shoot DVCPro at high definition 720p. Or if you’re finishing on 720 HD, then shoot 1080i. And if you’re going for 1080i shoot full resolution like HDCam or Red Camera.
3. Never, ever shoot DV or DVCam for green screen – The video compression from camera to deck makes it neigh impossible.
4. Oh, and it doesn’t have to be green – Today’s devices just want a color. For example, in one project there was a need to literally paint an image on. A blue “canvas” was used and the talent used a real brush to paint red paint onto the board. In post the blue was replaced with one shot, the red replaced the incoming shot. Clever, eh?
