Luma shift problem

Hi all,

I've got a moving background I'm using in various sections of a video... it's something I rendered out in FCP, exported as a QT, then reimported.

Trouble is, whenever I put something on top of it -- moving video in a box, title, anything -- and render it out, I get a "pop" in the brightness right at the point the overlay clip on the higher video level begins and ends (even though the overlay clip opacity is 0 at those points as I'm fading it in). The background gets about 10 - 15 IRE brighter. For some reason, I don't see the shift on the FCP waveform monitor.

I've tried re-rendering the sequence using "white" instead of "superwhite", but it was no help; also I don't have the RGB render box checked. I'm on OSX so I don't think the RAD DV extension others have mentioned applies to me.

I have a Kona card and originally offlined this sequence in DV (the source material is Beta), and had the same problem then. I had hoped that when I created a new project and redigitized at 8 bit, the problem would go away, but it hasn't.

Any ideas? Thanks in advance.

Mike


Michael Rothenberg
Peak Productions
617-924-0550