View Full Version : Field order help


Eric Gan
October 17th, 2007, 05:42 PM
Hey guys, I'm really stumped here.

Just finished a project in FCP5, exported to 16:9 anamorphic NTSC SD, imported into iDVD and burned. I've done this many many times and this is the first time I've seen this horrible jittering effect. Especially bad on pans and any sort of camera movements, but still obvious when camera is stationary and subject is moving. It's really bad.

Everything I know points to a reversed field order. I've double checked my FCP timeline (lower field), re-exported and burned. Still the same. I"ve even used a PC app called DGIndex to check field order on the resulting DVD and it says lower field. I've even gone back to iDVD6 from iDVD '08 just to make sure nothing in the program has changed. Still the same.

I'm not sure what else I can do. Should I try upper field? That doesn't make any sense to me. Video looks fine on computers. Jittering on both set-top dvd players.

Any help is appreciated. Thanks.

Andy Mees
October 17th, 2007, 10:15 PM
your timeline may be set to lower field but is the source footage lower field? if its not, did you remember to add the shift field filter? if it is, did you (or FCP) add the shift field filter in error? where did the source footage come from? when you play this footage in the timeline and view on your external reference monitor (eg firewire --> camera/deck --> tv) do you see the jitter? my guess is you do. you won;t see interlace issue on the computer monitor, it is not an interlaced display ... that, amongst other reasons, is why you're expected to always view on a reference monitor

either apply the shift fields filter (or remove the shift fields filter if aleady applied) the reexport and burn, or take the existing export and run it through JES Deinterlacer to reverse the current field order

Eric Gan
October 18th, 2007, 01:07 AM
Andy, thanks for that. I did figure out that I needed to use the Shift Fields filter. The weird thing was that it only affected certain clips, so it was not a simple task of applying the filter to the whole timeline.

The source was downconverted NTSC HDV (through camera), so in effect, it is anamorphic NTSC DV. It has always been lower field first on all the projects I have done this way.

A few factors changed in this project which must have contributed to this problem. I have not narrowed it down, and unfortunately, I don't have time right now to sit down and isolate the problem. I use Magic Bullet editors extensively. I recently switched from PowerPC to Intel Mac version. There is one segment where the only filter applied is a Magic Bullet look, and the Shift Fields filter had to be used to fix the strobing. In other parts of the project, the Nattress film filter may also have done something to change the field order.

Well, it was a whole day wasted chasing this ghost. Although I have fixed the problem by selectively applying the Shift Fields filter, I still can't narrow down the source of the problem. I will update this thread when I have more time to look into this. For now, I have to move on to the next project.

Cheers,