I see.
According to iPi Soft, higher framerate is actually more important for accuracy than resolution but I imagine resolution becomes important if you want to increase the size of the capture area. Is this what you're wanting to do?
(FYI, framerate is important because you want to capture as much motion data as possible for fast motions while minimizing motion blur. And while higher resolution should result in higher res volume but I don't think the extra volume detail necessarily translates as more accurate motion. However, higher resolution can certainly mean better accuracy for actors that are far away from a camera.)
Anyway, as mentioned above, you can assemble footage from different cameras using a compositing program like After Effects. I recall 1k0 did this a few years ago to conform footage shot with two different Panasonic DSLR cameras and a single PS3 Eye camera. You can see the results here:
Danse Kabyle - Making of, part 1. Synchronizing the footage should be easy in a compositing program or video editor and I think the framerate may need be the same for each camera view. I suspect stretching lower framerate footage to match higher framerate footage may not be as successful as reducing high framerate footage to match lower.
You mentioned iPod and mobile phone cameras. With these devices, I think you may run into into 'rolling shutter' issues when shooting at high resolution that could affect accuracy. Also, mounting these devices on a tripod may pose a small challenge.
For these and other reasons, I think if you're going to go with an alternative device, it's probably best to use matching cameras.
It's been a while since I've seen the topic of mixed video sources discussed but I believe if you do a search in these forums, you'll find other threads on this topic.
Hope this info helps. Good luck! I'm very curious to hear how this goes. :)
G.
