If the SR sensor was contributing movement for cases where the camera was still, it would have shown up in the photo below. Here I was meteor hunting, and the photo is a 100% crop of a very small portion of the original, showing a satellite I caught. If the SR was doing things the trails of the stars and the satellite would be wavy or wiggly. This is an extremely sensitive test. The satellite image is barely 2 pixels wide, if that. I bring this up because I made the mistake of leaving SR on for this shot, and I thought, "Oh no, they will all be ruined" but they turned out fine. I could not have improved on the sharpness. This is better than any camera I've owned. Detail: Pentax K-5, 10s exposure by program delay, F/1.4, 50mm using Zeiss Planar T* 50mm F/1.4 ZK lens. Satellite at almost dead center, moving right to left. This image was checked with other sequential images to confirm it is a satellite.