motion tracking trouble in 24p
by Alex Beachum
on
Mar 14, 2008 at 2:07:48 am
I'm trying to track the motion of some standard def, 24p, NTSC video shot on a Canon XL2 using After Effects 6.5. Even though my track point follows the footage extremely closely, applying its motion to a null object causes the object to jump around more than the track point ever did. Does anyone know if this is a result of working with 24p footage, non-HD footage, or a little bit of each? I tried to attach a null object to some 30fps footage and that seemed a bit smoother. I'd really appreciate any and all help.
Re: motion tracking trouble in 24p by steve Roberts on Mar 14, 2008 at 12:30:35 pm
In case you didn't know, 24p video footage, out of the camera, is actually 29.97. That is, pulldown has been added, creating interlaced video. You should consider removing pulldown (file>interpret footage>main) before doing the tracking, so you'll be working with full frames at 23.976 fps in a 23.976 fps comp.
Re: motion tracking trouble in 24p by Dave LaRonde on Mar 14, 2008 at 4:13:05 pm
[Alex Beachum]"...I've already applied pulldown and am working in a true 24fps workspace."
I hope you actually mean 23.976 and not 24. The footage is NOT 24fps, it's 23.976 fps, which is the NTSC film frame rate. So if you're working in a 24fps comp, change it in the comp settings and do the track over.
If it really IS 23.976, check the clip's Interpret Footage settings. If the field order is still set to Lower Field First, try changing it to none and do the track over.
Still no joy? Make sure your track point stays within the limits of its inner box from frame to frame. You can change the size of a track point's two boxes.
