DVX100 and Chroma Key

W

Wildebeast

New member
I just bought a DVX 100A and have done a little composite work with a Green Screen. So far I have used the Boris plugins with Final Cut Pro and have been fairly pleased with the results, but I'm looking to improve on what I've been able to do so far. My main struggle is with the detail on the edges of my subjects, and I know this is a limitation with the Mini DV tape format because DV compresses chroma information so heavily (4:1:1). I have heard that some people, when they are doing chroma key work with DV cameras, will sometimes record video off of the analog outputs instead of capturing video to the DV tape.

1) Does anyone have any experience doing this?

2) What should I use to record the analog signal?
- A normal VCR would be too much of a sacrifice in video quality.
- I could buy a capture card, but of course I couldn't lug around my G5 to all my shoots.

3) Would some sort of Hard Disk recorder work?? They mostly seem to record in the DV format so I wouldn't be able to avoid that 4:1:1 compression.

Any help or advice about this issue would be greatly appreciated.
 
imho the analog out has absolutely nothing to gain over the digital output, its not uncompressed.. the signal has already been compressed before it gets to the analog outs. so all your doing ia trading a pristine digital signal for a lower quality analog one. imho you should just use good software like ultimatte or keylight to retain maximum video quality and get good keying as well.
 
The analog outputs blend the chroma signal together (i.e., from Y/Cr/Cb, the Cr and CB get blended together, so on S-video output it's Y/C). It's an irretrievable quality loss.

You can blend the chroma yourself in post, and sometimes it does lead to quite superior results for chroma keying. I can't tell you how to do it in FCP, but in Vegas 5.0 there's a filter called "Chroma Blur", which does a gaussian-style blur on just the chroma information. It can make for much, much smoother edge keys, at the expense of a little sharpness in the picture. Very useful. Perhaps FCP offers something similar?

If not, go to adamwilt.com, I believe Adam wrote up a plug-in filter that does a similar thing.
 
You must log in or register to reply here.
Back
Top