DV Artifacts Keylight
by Dale Paquette on Jul 9, 2011 at 10:38:01 am
I Know, don't use HDV for keying. That said, I do and have some decent results when green keying with Keylight. Several authorities (Chris and Trish Meyers, Mark Christiansen) recommend preping the footage by converting to YUV, blurring the G and B channels and converting back to RGB. The AE CS5 preset version specifically utilizes horizontal blur. Since HDV uses 4:2:0, which averages the G and B pixels in 2 X 2 blocks vs 4:1:1 which averages G and B in rows of 4, I'm thinking the channel blur should be horizontal and vertical, not just horizontal. The effect is very hard to see even at 800%, though I do believe I see benefits in the final composite. So, this is more a question for technical understanding of DV compression rather than an artistic issue. Am I right? Thanks
What can I say- you started with the obvious...
I did (forced by many factors) work with HDV and even DV for chroma and I got the best results using plugins like Ultimatte Advant Edge and Red Giant Key Correct Pro.