Keylight/HVX noise issue

dougspice

Veteran
Aha, the dreaded HVX noise problem rears its head at last. Currently I've been hired to fix some truly awful greenscreen keys that came from HVX200 footage. I've shot greenscreen on the HVX myself, and it's been more than fine, so obviously there's something wrong with the footage to start. Anyway, after quite a bit of effort, I've been able to get decent keys. The problem is that Keylight (or some part of the process) is noticeably amplifying the image noise! The gray areas after keying are just dancing pixel nightmares. I can't explain this. My mattes are perfectly opaque in foreground elements, and I'm applying no compression to the renders. It appears in RAM previews as well. Any ideas?
 
Have you turned off Keylights spill suppression? I find it usually messes with my edges a lot. It's best if it's turned to intermediate result, instead of final.

Heroic
 
You could just use the matte that is generated from Keylight, and apply it to your original footage. That way you wouldn't be getting any artifacts that Keylight is giving you. Oh wait...I remember a greenscreen project I did with Keylight (using the HVX) and the same thing happened to me...it was fixed easily with a simple setting...let me go into that project and figure out what I did...OK, found it...

This might help...
In Keylight go to the "Screen Matte" section. Choose "Source" for the replace mode (instead of "Soft Colour"). That will probably fix the noise issue that Keylight is giving you (it did for me).
 
I get this a lot too on people and their clothes. What I normally do is crush the blacks. Sometimes I'll duplicate the video keyed layer, and on the top one I set the blending mode to "overlay", gaussian blur it to about 5. Then I make the opacity on that layer about 20-50%. Gives sorta a cool look too.

~John G.
 
Hey, I was away on vacation after wrapping this project, and I didn't see the reply in time, but MrPolarBare was more or less right about what needed to be done. On a few of the shots I also had to just go and throw out Keylight and build my own key.
 
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