Incromprehensible jitter on sl | Forum

I've tested with 2 cameras, one on tripod, one sort of PTZ. Slow panning creates some random jitter/slide. I’ve got the same results on my motorized jib from edelkrone. It's not much but enough to make these type of large & slow beauty shots not usable and it’s very frustrating.

Please look at the result : https://youtu.be/79pKtf2b-Ow

Any idea on how to improve that, either through Vive or Axi ? I’ve spent a ton of time to perfect the results of my tracking and I need to understand now if it’s a level of precision that is reachable with Vive Mars Camtrack, or if I should just accept that it can’t be done and just move on.

Context :

> 4 base stations on a large and steady structure, no shaking possible

> Very far from CPU/GPU overload on Aximmetry

> Calibration of lens/offset done with both Aximmetry Camera Calibrator and Mars Calibration Tool, same result

> Vive tracker was not under a strong light

> The 2 first tests have been recorded with Tracking Stabilization at the middle value, the last one I shut it down totally (on the video I set it at low but actually I shot it down)

> Genlocked workflow, Delay has been correctly found and set

> Everything up to date : rovers, stations, mars camtrack, axi, ...

Thanks a lot for your lights !

whoozben

Stefan Reck

For Aximmetry Calibrator the accuracy of the lens calibration is actually impressive. The movement of the set relative to the real objects you see around the 2 minute mark is due to the remaining imperfections of the lens calibration data. You could improve on this by using an external lens calibration tool like EZtracks EZProfile. They also offer that as an on-site service if you do not have their hardware, and they are based in France. One thing that might improve the s/n ratio of the tracking data while panning is mounting the tracker not directly on top of the camera but about 10-15 cm above and in front of if. You'll probably need a cage for the camera to make this mechanically solid, but it worked well for us. It gives the tracker a mechanical advantage over its own noise that can then be clamped out with either the filter in Mars or the dejittering option in Axi. With your setup it might also be worth looking into a different tracking technology. ReTracker Bliss for example offers much lower jitter at the expense of greatly reduced range (which you might not even need in this case...)

Incromprehensible jitter on slow camera moves w/ Vive Mars

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