Vegas chromakey with webcam/whitescreen - tips?

ken c wrote on 8/10/2015, 3:21 PM
In addition to always using keylight/greenscreen in AE w/properly lit studio as I've done for years....any tips on sony chromakey w/hi-def webcam white background?

I'd like to quickly produce youtube lower-res (480/720) chromakeyed videos, podcast style, any tips?

it looks like impossible to key off white background; unless I'm missing something..

related: https://forums.creativecow.net/thread/2/977083

thx,

ken

Comments

Former user wrote on 8/10/2015, 4:06 PM
You normally can't chromakey off of white because of the nature of chromakeying. It normally requires a color, and white is reflecting all colors.
You can sometimes do luminance keys though.
OldSmoke wrote on 8/10/2015, 5:29 PM
@DonaldT

Not true. In the digital world white is a color, 255,255,255 would be white therefore you can key it.

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Former user wrote on 8/10/2015, 5:48 PM
Have you successfully chroma keyed off a 255 255 255 white?
You don't normally get this kind of white in a studio camera shoot.

I did create a graphic with 255 white and was able to use the chroma key to make the white transparent. Curious though if this would work with white shot in a studio.
TheHappyFriar wrote on 8/10/2015, 7:36 PM
Using the mask generator might be better suited for really dark/bright shades of white & black.
larry-peter wrote on 8/11/2015, 9:50 AM
The philosophy behind chroma keying is to select a background that has the least chroma/luma in common with the foreground. If you have a pure 255,255,255 background you may be able to get something workable with it. But if it's not lit to pure white, you've got a gray background and that will be trouble in keying a lit human subject. Highlights, shadows, eye whites, teeth are all potential problems.

Vegas' keyer only has tolerance controls for luminance of the selected color. Getting a clean edge without affecting the grays present in the foreground won't be easy. As very least, you may have to generate a separate (choked) matte to hold the majority of the subject, and another layer+matte to attempt to get a clean edge.