slightly OT - strobbing on some assets

This is a little off-topic but I'm getting strobbing on action (wrong field dominance?) in some clips (only visible on an NTSC monitor) though I've used the same work flow to export a Qt from an Avid, then use the same setting in Compressor.

10 out of 12 clips look great. As a work around, I have the problem clips on anther dvd (prepared in Toast) that I extracted as separate Elementary Stream files using Cinematize. Substituting this it worked with on one problem clip but not the other. Again I think I'm using the same work flow and get this different results, probably should take a break and revisit tomorrow.

Thanks for any suggestions,

PAul

Thanks. In Compressor I had been working with my custom preset that interpreted source video (Avid Qt exports) as bottom field and everything worked fine. (except for the problem two)

At the risk of turning this into voodoo I'll mention that the one thing the problem assets have in common is that I think they were originally sourced from a dvd. Now they all looked fine playing within the Avid so one would think the same workflow to Compressor would suit everything, it's a puzzle.

Yes, monitoring Avid on an NTSC monitor.

I'm thinking I was too quick to call my strobing problem one of field dominance. On closer inspection one sees that there is a band pattern to the weirdness. The attached sample shows a freeze during a fade-up, a pan across straight vertical lines would show horizontally displacement in 6 bands. I think of field dominance being manifest on every other scan line not as big bands. Again, was I too quick to call my strobing problem one of field dominance, if so what is it?