I see that in Video Pilot's Tutorial about Keylight that he uses a .mov file. Is there any advantage to using that file over using a .AVI file? I am using "keylight plugin" works pretty good.
I am getting pretty good Keys but am looking to get a bit better and would like to explore the formating options that may give me better results.
any experience is welcome... Does and Do Nots thanks.
Re: Best For keying Footage? by Darby Edelen on Mar 18, 2008 at 8:39:56 pm
[Christopher Loehrer]"I see that in Video Pilot's Tutorial about Keylight that he uses a .mov file. Is there any advantage to using that file over using a .AVI file?"
Depends entirely on what codec is contained in the MOV or AVI. Some codecs have chroma subsampling that limits the resolution of the chroma channels (the color in the footage, which is what you're using to key with) to 1/2 or even 1/4 that of the luma channels.
Other than that and the standard compression artifacts there shouldn't be too many codec related issues with keying. You'll likely run into far more trouble if the footage was not lit and shot correctly.
Darby Edelen Designer Left Coast Digital Santa Cruz, CA
Re: Best For keying Footage? by Christopher Loehrer on Mar 18, 2008 at 8:53:14 pm
in the case of AVI which settings would you suggest to acheive best results. Codecs? MIcrosoft uncompressed AVI 10-bit YUV (4:2:2), DV AVI, or just AVI?
Re: Best For keying Footage? by Dave LaRonde on Mar 18, 2008 at 9:19:47 pm
To elaborate on what Darby said, it's all in how the footage ORIGINATED. How you shot it.
If you shot DV and then bumped it up to Quicktime's Animation codec at best quality (it's losssless), it's not going to make DV footage look any better.
There a great, not-very technical podcast floating around the net that explains the difference between 4-4-4, 4-2-2 and 4-1-1 color sampling. It's part of the MacBreak series of podcasts, and it's called "The Road To 1080P Part 2". VERY instructive. Well worth the fifteen minutes it takes to watch, and it doesn't matter if you're a Mac or Windows guy -- the principles still apply. It's just a google away, and I highly recommend it.
But just as important as the type of footage is the lighting. If it's poorly lit, you could shoot with George Lucas' personal HD camera and the key would still look lousy. Again, you can google "lighting for chroma key", "lighting for green screen", "lighting for blue screen", etc. to learn just how important it is.
Re: Best For keying Footage? by Darby Edelen on Mar 18, 2008 at 9:38:09 pm
[Christopher Loehrer]"in the case of AVI which settings would you suggest to acheive best results. Codecs? MIcrosoft uncompressed AVI 10-bit YUV (4:2:2), DV AVI, or just AVI? "
This will often be determined by the media you use to shoot the green/blue screen footage... miniDV, for example, is 4:1:1 and there's nothing you can do about it. You can use various techniques to smooth the chroma channels so that they will not be as blocky, but you can't run 4:1:1 footage into a 4:2:2 codec and expect amazingly improved results. So I guess the question boils down to: how are you getting your green/blue screen footage?
Darby Edelen Designer Left Coast Digital Santa Cruz, CA
