Interlacing

I spent 11 hours on Friday fixing a show, which was cut by an editor outside of Link, the day before air. One of the big problems with the show is that the editor didn't seem to have any concept of interlacing. For example, HDV and DV have different field order--HDV is upper field first, and DV is lower field first. You can't just throw them together in the same timeline without some processing. That processing is namely the "Shift Fields" filter. When editing HDV that's in the viewer into a DV sequence using the overwrite or insert command, FCP will automaticaly apply the Shift Fields filter with the correct setting--it also scales and distorts the video so it looks proper. However, I think if you just drag an HDV clip into a DV timeline, then FCP does not apply the filter, scale, and distort settings to the clip.

If you don't apply the shift field filter when you are mixing footage with different field orders, then you will got stuttery playback. Chris & Trish Meyer have a good write-up on fields along with all the particulars you need to know to handle interlacing in After Effects. Check out this article from ProVideo Coalition:
Field Order - Who’s on First?

I suspect that the show that I fixed was edited on an LCD monitor. FCP makes it easy enough to use a computer LCD to display footage that I think more and more people are doing without a video monitor. Some might even say that interlace is dead because 99% (not actual number) of new TV's are progressive anyway. Well, as long as you are delivering for standard-definition, then I think you have to got to look at your show on a CRT monitor that can properly display interlace (except for those rare cases, when you have a 24p show that is only going to DVD in standard-def.) There will be plenty of CRT TV's around for a long time, and plenty of broadcasters using 480i or DVD video encoded as 30i.