Herb Chong asked: "have you used any Canon IS equipment, particularly their binoculars? you still haven't said anything that says a pendulum isn't an accelerometer. it measures acceleration and does something. the gyros inside Olympus equipment for IS also measure acceleration and does something. all Canon has done is have it do the detection mechanically. however, since having IS enabled uses a lot of power from the camera body, that something is power actuated, even if it is mechanically controlled."
My SO has a Canon IS lens for her D60. I haven't really messed with it much but I did read the Canon literature that explains how their IS works. A pendulum by itself doesn't do anything. By definition it's a suspended mass. It can be used to observe acceleration but additional equipment must be added to measure that acceleration. In my world, that doesn't make it an accelerometer. Again, the context of my reply was to the statement: "You'd need to measure the movement of the camera, which could be done using a sensor of some sort in the body, or could conceivably be done by measuring the movement of the image on the CCD. This could mean that IS could be added to the *istD by a firmware upgrade." It is still my opinion that placing little accelerometers in the camera body to measure the amount and direction of movement and then operating other devices to counter that movement would be a kludge. The movement would have to be calculated and predictions made on future movement to make the adjustments in real time. IMO making adjustments for movement that already occured would result in the sensor alignment always being slightly behind. Use of gyroscopes to provide a steadying lens element is a far more elegant solution to the problem. I'm not familiar with the Olympus IS methods so I can't comment on how they work. Tom Reese
