I have been using Motion (and, specifically, the DV Matte Blast Plugin) to chromakey green screen backgrounds, and roundtripping with Final Cut Pro. When I play the clip on the FCP timeline it flickers quite badly when there is even the slightest bit of movement. If deinterlace in Motion I see some improvement, but it's still pretty bad. If I deinterlace the clip in FCP the flicker disappears completely.
I am reluctant to resort to simply deinterlacing in FCP because I do not want to lose resolution. My understanding is that deinterlacing in Motion is more effective.
The footage was shot in HDV Pal using a Sony Z1, and downconverted to SD in camera. I know that HDV Pal is upper field dominant, and SD pal is lower field dominant, so I'm not sure if this is causing a fields issue. I am working on the understanding that when you downconvert to SD the footage changes from upper to lower field dominant, and my timeline is set to lower field dominant.
If anyone could shed any light on how to solve this flicker problem it would be most appreciated.