Tips for Chroma Key

by Dyske Suematsu  •  April 21, 2004

These are things I have learned through working on various green screen projects. This paper assumes that you have a basic understanding of what chroma key is. If not, there are many resources on the Web for it. Here is one of them:
The Blue Screen Page

If you have better solutions to some of our problems, or if you disagree with any of the tips provided here, please contact me.
1. The Ideal Green — How to achieve the best possible green for your background.
2. Deceptive Colors — Some colors in the foregound elements may not look green, but they may be.
3. Separating Among Foreground Elements — You are so concerned about separating foreground from background that you forget separating the foreground elements from one another.
4. Problems with Dark Edges — You want the edges of the foreground subject to have as much contrast as possible. If not, here is what happens.
5. Hard Shadows — Although it is possible for sophisticated keyers to retain shadows, you do not want any hard shadows. Here is what happens to them.
6. DV versus DVC Pro — Some keyers can reverse the compression algorithm of DV footage. Here is a comparison between DV and DVC Pro.
7. Shutter Speed — Motion blur could be problematic in keying. You can avoid it by using a higher shutter speed.
8. Interlacing — Interlacing isn’t a problem for keying, but it is for many other reasons.
9. Unnecessary Overlap — Reducing the amount of manual clean up by detecting unnecessary moves.
10. The Importance of “Clean Plate” — Understanding the significance of the accuracy of clean plate.