For a camera in motion , it doesnt take much motion blur to blur neighbouring pixels of HD resolution into SD resolution, in other words given that motion blur is in the scene an SD shot resized to HD format would look pretty much the same as if the scene was shot in native HD.

I wonder what people's thoughts on this are and whether there is an optimal camera resolution/format for stabiliser work?

John:

I think this may be overthinking things. I don't believe that once an HD image starts to move it suddenly looks like an SD image. My limited tests with HDV did not produce this effect. Have you experienced something to the contrary?

Yep

We've been doing some work for an Architectural/ Property Development company which involves a mix of fly-through animation and HD video.

While rendering with full textures we decided to do some test renders without motion blur until the speed of the fly through can be signed off by the customer. After applying motion blur [180 shutter] through an application which computes motion vectors we were astonished to see all the finest texture details vanish in the motion blur. Through hindsight we probably could have saved two weeks of render time by rendering at PAL SD resolution and resizing to HD

Thinking about it motion blur has a low pass filter effect, thus proportionately HD has more to lose than SD for the same level of motion blur , which in our case amounted to about 2 foot/sec