Steve,
I was using a Sony PMW EX3. The reason props stop or look odd is because the frame rate and shutter speed are not synced properly. Normally the frame rate will be half the shutter speed. If you are shooting at 24 frame per second shutter speed should be 1/48, 30 should be 1/60, etc. If you are using a video camera and set it to automatic then that will cause the prop image problems as rates are no longer synchronized properly. You need a camera with full manual controls. In the movie world this cannot be varied as fast moving objects will never look right to the eye.
I see a lot of otherwise great airplane videos ruined by this problem.
I strongly recommend the Canon 60D DSLR as it will do a fantastic job on HD video and is low in cost. You can use any Canon EOS lens with this as well as older Canon film camera lenses. A viewfinder adapter will also help with video work while using a DSLR. I sold my Sony EX3 and now use only the Canon 60D. You can also get excellent depth field with this camera which cannot be done with most conventional video cameras (including the EX3). Hope this was a help to you.
