Originally posted by v5planet The sensor is positioned magnetically even when the camera isn't attempting to eliminate vibrations?
Yup, all turning off shake reduction does is tell the camera to position the sensor in the start position and keep it there.
That's why when you turn the camera off, you can here the sensor flopping around inside the camera if you rotate it.
Originally posted by Laurentiu Cristofor But what is the difference with the K20D? Is the SR mechanism different in cameras post K20D?
The principle is the same, and for the purpose of this particular discussion, there isn't any difference.