ORIGINAL: bjr_93tz

I'd say that was a camera effect, the same as what was happening with the prop.

The ailerons were not moving or being moved significantly (to my eyes at least) but the elevators were moving, so I call the vibration of the elevators was being picked up and smoothed out like the rotation of the prop, they look like they are moving smoothly when in real life they are actually shaking like crazy....

A tip to watch out for is that the elevators stop moving when the prop stops moving, section 45sec - 56sec shows this very clearly.

Very interesting to see just how much shaking is happening back there