EOS Bodies - For Stills / Re: *UPDATED* 5D Mark III Issue with EF 200 f/2L IS Official Canon Response« on: March 30, 2012, 06:08:16 AM »
Does anybody has any idea why these strange sound appear? Is there any new algorithm of IS drive implemented? I thought lenses have their own processors taking care for optimal IS operating. If camera itself has such an influence on IS operation then it can occur, that IS effectiveness depends on what camera lenses are mounted on. That's something new for me.I can't speak to the algorithm but keep in mind that this issue is only happening at with AI Servo where there is constant or near constant communication between the body and the lens. When you press the shutter (or AF-ON) on a body it sends the signal to start IS and obtain focus, in my experience it shuts off in five or six seconds with no shutter release or if your finger is removed from the shutter. With AI Servo that is constant so that communication way different, it verges on chatter so any tweak to the algorithm could make a particular lens design totally wonky.