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dwindholz
12-17-2003, 04:29 PM
any advice on setting up a green screen. We've tried it and are getting OK results. Nothing I'd like to put out to tape.
Can someone help?

Jim_C
12-17-2003, 04:38 PM
If you are using a DV camera use the svideo out not DV, as long as it is before compression.
Use opposite color (red, magenta) for back light and lots of it.

http://www.digitalproducer.com/2003/11_nov/tutorials/11_03/gogreen.htm

http://www.videotoasternt.com/forums/read.cgi?11559

http://www.videotoasternt.com/forums/read.cgi?13738

couple threads and an article to help.


Jim

djlithium
12-18-2003, 12:20 AM
One of the things I still see today even with pro DPs and gaffers is they overcrank the screen with light. This is a big time no no, but telling some of these guys will get you fired. Of course in my job that is what I am supposed to do. :)

You should not try and turn your green screen into a massive light bounce. Working with a DP here in Vancouver who has done a lot of VFX shots over the years (and after building our own 24ft wide 16ft tall 3ft to vertical transition, coved digicomp screen), we found the best thing to do is to light the screen so that its even, but keep it at least half a stop under from the rest of your scene. This way you don't over blow it, starting to turn that digicomp green into a yellow, or worse, creating a massive amount of spill on your subject.

The other thing to do if possible, is to pull your subject and camera as far away from the screen that you can. This will help to reduce spill and eliminate the camera from picking up variations or imperfections in the screen like seams or touch up splotches.

And another thing, dont use DV. DV does not have enough information per pixel (4:1:1) to pull a clean key from it anyway. Go DigiBeta or BetaCam SP component. Hell, a tripple CCD Hi-8 Camera using the Svideo out will probably give you better key then consumer and even prosumer/ENG cameras.

Also, always record uncompressed into your T3.

ted
12-18-2003, 11:03 PM
In brief, Make sure the background is evenly lit.
Make sure and separate the talent from the background so there is no color bleed on the talent.
Give plenty of backlight to your subject for better separation.
Possibly add a slight peach or warm color gel on the backlight.

If possible, use SDI or Component feed. Composite or DV isn't the best for Chromakey.

If still not happy, there are plenty of key programs available. I recently heard that Ultra Key works pretty good even with composite or DV.

There is a lot more to learn, but without knowing more about what you are specifically trying to do, this is a good start.
I wish you luck.

Some has been greatly covered above, but here is my quick list.