Wierd Thing Happens When Working With Greenscreen

[Shane Ross]

DVCPRO HD and keylight in AE don’t mix. Trust me…I’ve tried it. The issue is that Keylight doesn’t quite keep the footage “solid.” It is slightly transparent…or SOMETHING…because I got heavy artifacting when I used it. I liked how keylight kept the motion blur, but it just brought out big compression issues. Go to my blog and see what I was dealing with. You will have to go down a bit: http://www.LFHD.net. I posted examples of what I was running into.

ANWAY…my solution? Shake. This allowed be to create a HOLD OUT MATTE that made the center of the men rather solid, I then used keylight for the edging so that I could get the blur out.

If you can make a hold out matte in AE, then that is what you need to do. I couldn’t figure it out, and since a buddy of mine is a Shake master and knew, I bought it.

Shane

Littlefrog Post
http://www.lfhd.net

[Nick Toth]

Did you try changing the alpha channel interpretation in FCP? Livetype renders always have to be changed to
“black” from “straight” or they don’t key right. It’s worth a shot

[Peter Mcauley]

I think Nick is onto something. I had the same problem once. Get info on the the clip and select format. Under alpha you can right click the different alphas.

Good luck

Peter McAuley
Axyz Edit
Toronto
G5 dual 2.0
4 gigs ram
10.4.3
FCP 5.04
QT 7.03
Kona 2 v1.1.4 with K Box
4 X 250 gig external F800 Lacie firewire drive
2 X 23″ Apple cinema display

[Rick Diamond]

Why not just build the whole comp in AE and forget about exporting with alpha channel?

Rick

[Jeremy Garchow]

I would definitely take the advice of switching the alpha from straight to premultiplied (can be done the browser), and I would also double check what your BG color was when rendering out of AE, it should be black. Sometimes AE will pick up a little of the color in the alpha channel and display it in FCP. Changing the alpha type should remedy this problem, though.

Jeremy