Green Screen Jaggies

[Mike Clasby]

Did you try a little pre-Blur?

https://av.adobe.com/tips/aft6ttgreenscreen_580_456.mov

Maye a super tight junk matte would help, see Aharon’s tut. It uses Auto Trace to make a tight matte and the hair on the talent is better. Bad Hair Day be gone:

https://forums.creativecow.net/articles/rabinowitz_aharon/junk_mattes/index.htm

Also search for “DV Key” footage, lots of stuff on that. Like this:

https://forums.creativecow.net/readpost/2/913090

[Matthew Mccarter (macattack)]

I know that a Take 5 segment on Digital Juice covered Green Screen Jaggies by telling us to reduce the sharpness when filming. I know that doesn’t help now, but in the future it might come in handy.

Make sure you try the pre-blur option. And use Keylight instead of AE’s built in keyer, its not that great.

[Brendan Coots]

In professional compositing situations artists commonly duplicate the footage layer and use masks to break their greenscreen plate up into individual elements, so that they can use fine-tuned settings for specific needs. In this case, the head should probably get different Keylight settings since hair is much different than the edges created by clothing etc. It requires more work, but here’s the idea:

1. On your base footage layer, create a mask that separates the head. The mask will probably need to be animated to follow the character, but it should just be a loose “garbage” mask

2. Put the mask in “invert” mode, so that it only shows the body

3. Duplicate the layer. Uncheck “invert” on the mask for this layer so that it only shows the head of the actor. The two layers stacked should show the entire actor without mask seams

4. Tweak your Keylight settings on the head layer to taste

5. If you need to radically adjust the head’s key settings, the seam between the two layers may become obvious. You can get around this with a combination of mask feather/expansion settings on both masks so that the two layers softly overlap at the seam.

Most of the jaggies you’re seeing are probably a result of the inherent limitations in DV video. You can try DVMatte instead of Keylight, may work better since it’s specifically tuned for DV footage.

Brendan Coots
Splitvision Digital
http://www.splitvisiondigital.com