ChromaKey bleed-through after render

[Mark Suszko]

Is this really keying off the jacket color, or moire’ effect from a pattern on the jacket?

You could add a mask layer in the key in the are of the problem in the jacket.

if you have FCP7, you should have the Primatte RT keyer available: it is superior to the Apple keyer.

[Michael Moser]

Both good ideas…Thanks.
I also reduced the background video level. I’ll keep futzing with it.

What I’m concerned with is that each change seems to work fine before the render, but then the problem reappears after the render and is slightly worse when I output it as a Quicktime .mov to be used as an element. I try to play it close to the edge level-wise to achieve a realistic key, but it seems the black and video levels change during render and output thereby exacerbating any little problems.

I’ll try both solutions to see where I get.

I’ve got Keylight, also, which I can play with, but I’m trying to see how these levels change and interact with each other as I make the incremental changes.
Mike

[Jerry Wise]

are you trying to chroma key an h264 source?

[Mark Suszko]

If it looks good but then re-appears after rendering-out, maybe it’s not the key but that you are transcoding to a wrong codec setting?

[Michael Moser]

I’m starting with XDCam MPEG 4:2:2 (a Sony F55) and transcoding to ProRes HQ on the render. Green screen evenly lit, so it has to do with the key settings, I think.

[Michael Moser]

I’ll try that…
Never has been a problem in the past and I had been working with material from the PMW-350 and the F3 which are 4:2:0.
I originally was double recording to a KiPro for that reason, but since I was able to pull a good key before, I stopped using it.

[Michael Moser]

That’s right. The KiPro records 4:2:2 from the SDI port as ProRes.
What I’ve ended up doing, in this case is matte-ing out the background behind the subject using the 8 pt garbage matte inverted…That seems to have solved the problem for the moment, though I still need to QC it on a larger monitor.
I’m going to try the other solutions though to see where the problem lies…
Michael Moser

[Michael Moser]

By the way- There was no problem with moire on the jacket…but totally independent of the chroma-key issue–the tie did cause a problem; and it wasn’t because of the pattern, but the weave of the tie which was very reflective and moire-ing like crazy…not visible, by the way, on the production monitor at the shoot.

It was particularly bad on the knot of the tie. I layered a little square over the knot with a touch of gaussian blur which hid the moire.

….All this to make it look like a guy was sitting in front of a window.
It’s amazing the hoops we jump through to make it look like no hoops were jumped.