Strobing or Stuttering motion

[SF Geek]

I have a composite of single med shots of People in front of a white cyc. I tracked them along at the bottom of the screen like a conveyer belt with keyframes on horizontal positioning. No matter what speed I track them at, they seem to stutter and strobe. When I do a RAM preview they don't have that problem, but when I render them to quicktime the strobing is distractingly apparent. I've tried motion blur and no motion blur and it strobes both ways. Anyone have experience with this and know how to do a workaround?

Footage is 1080p 23.98 and is rendered as the same.

[Arson]

It sounds like your export interlace settings are doing it. Maybe reversing the original field order.
Is your source footage a mix of different framerates?
Try exporting as an image sequence (png, tga, tiff) or with a different field order.

[grahamdunn]

In the past I've rendered a credit sequence at 60fps because the extra frames caused the motion to smooth out. Not sure if that helps, but 23.976 can cause that strobing due to the somewhat low framerate. You can see this in movies when they pan or dolly, etc.