I've been supplied with some animated astons by a graphics house, with the intention of resizing and using a screen composite to overlay them with the footage. Normally easy (although the first time I've done this in MC/Symphony rather than in FCP, Premiere or a DS).
When I just do a straight screen using either Avid FX or BCC Composite the pure black background overlays as if it were gray, so repositioning and rescaling the astons aren't possible that way. You can't even adjust the levels/brightness and contrast because it alters the area underneath too.
But I found that using Avid FX I could put the aston graphic in a 3d container, adjust the brightness and contrast of the graphic layer and set the 3D container to composite in a screen mode and get the desired look. A bit long winded but once set up presumably I can just drag and drop the effect on, so no big problem.
However, when I come out of Avid FX and back in to Symphony the whole image gets a slightly lifted, blue tone added to it. Weird as it looks great in Avid FX AND the blue shift isn't isolated to just underneath the area of the aston which seems to be the way these things normally happen in Avid.
I'll admit to being a bit of an Avid novice, I certainly don't know it as well as I know FCP, Premiere or the DS but this seems like a silly problem that must have a sensible answer. I've found other mentions of this problem online, but no answers.