Chroma Keying Problems

Question

Chroma Keying Problems

Hi. I am having some trouble with chroma keying on FCPX. Not the exact type of keying you might think. In different occasions, I've taken an image that was not created with a camera (i.e. a scan) and imported it into Final Cut (also done with motion). I have one subject in the image and the image has a different, solid background color. After I import, I use the "Keyer" effect and select my sample color. After doing that, my background is keyed out, however, a thin line appears around the edge of the original picture. I've played with the tweeks in Inspector but I cannot seem to completely remove the thin border lines.

This is a video that I have made that includes this pesky problem at 18 seconds:

http://www.youtube.com/watch?v=QNM71QWhgdQ

Thanks for your help!

**Note: In the video, I say I use a PC and a different software for keying but I still used FCPX on my Macbook for the part that is troubling me.

Final Cut Pro X, OS X Mountain Lion (10.8.2), 15"

Posted on Feb 17, 2013 7:05 AM

Reply

Answer 1

Feb 17, 2013 11:51 AM in response to Ironnarwhal180

1) The lighting of your green screen is not very good. For optimum results you need to evenly light it. So that the entire screen has as much of an identical green as possible

2) Judging by your camera you are probably using a 4:2:0 Codec which is very very far from optimum when using green screen.

Still your lighting is the most important thing. Yours has so many shades of green -- ranging from 0.29 to 0.56. An evenly lit screen should have MUCH less shades of green. And possible NO RED and NO BLUE. Yours has lots of red and lots of blue.

I'd start there and perhaps wait with the tutorials until I got it right. No point in teaching others how to do it wrong ;-)

Reply