28-70 f2.8L Manual focusing ring does not rotate smoothly. Can anyone advise what, if anything can be done. I generally use autofocus but I'd like the manual ring to operate silkily if poss. Hope you can help. John Michael

-- John Michael (surfjma@btinternet.com), February 20, 2002

Answers

I have not used this lens, but I have heard of this problem before. There isn't a lot you can do, because it's due to the design of the lens. The problem stems from the fact that during the focus movement, one lens group changes direction of movement, and the leverage of the cams used to do this changes through the focus movement, which causes the movement to be stiffer at some focus positions.

-- Isaac Sibson (isibson@hotmail.com), February 20, 2002.

My 28-70 rotates smoothly, if not with a deliberate motion on my part. That is, it has enough tension to prevent the accidental rotation of it. It is a bit of a heavier touch than my primes.

-- Chris Gillis (chris@photogenica.net), February 20, 2002.