canon says it should not be done. but it doesn't say what happens if one unmounts the lens with IS on "1". does anybody know what happens. one may forget to switch IS off before unmounting. or the IS might get switched ON before mounting and unknowingly on might mount the lens with IS ON. will either case affect the functioning of IS or lens or the camera.

thanks

-- sajeev (chack74@yahoo.co.in), February 21, 2002

Answers

I know I've done it (inadvertantly) with my 28-138 without any it showing any ill effects. I may have been lucky. I also try to always turn the camera off when changing lenses so that may have a bearing also.

Dick

-- Richard Tope (RTope@yahoo.com), February 21, 2002.

I just checked the manuals of the 28-135 and 100-400 IS lenses. No warnings are given about changing the lenses with IS on "1", the latter manual warns against removing the lens when IS is activated. This may happen inadvertendly when you press the shutter button when changing lenses. Normally I think the time to handle the camera and to get the other lens is long enough to stop IS working. IS stops working when the exposure information dissapears from the display(s).

-- Jos van Eekelen (jos@compuserve.com), February 21, 2002.

yes. what Eekelen said is true. i didn't realised this. one should not unmount the lens when the IS is ACTIVE. there is no problem in unmounting the lens with IS on "1" as far as you are assured that the IS is not active. thanks Eekelen and Tope for your useful bit of information.

-- sajeev (chack74@yahoo.co.in), February 22, 2002.