[smile-123]

The only literature I've seen about the Pentax Image Stabilization feature is (1) that it gains you 2-3 fstops of useability and (2) that in some instances you may want to disable it. Its this last part that I wondering about. You would think that above some shutter speed, the anti-vib would be disabled. Is it? You would also think that the system would decrease the vib sensitivity as shutter speed is increased.

Some of my pics show definite vibration at, what I would think is, sufficiently fast enough shutter that it shouldn't be there, say 1/3000 at 500mm? Yet I see this doubling or tripling effect that sure looks like camera shake.

Does anyone know more about how this works, specifically if it automatically cuts out?

I have always left the anti-vib ON except in a few long-exposure tripod mounted situations. I am thinking that perhaps I should normally leave it off unless I am in a specific situation that needs it. Anyone have a 'best-practice' opinion?