This was on http://stans-photography.info/
Bill Peifer - (...) One thing to watch for on these (70-210) is looseness in the zoom/focus collar. The collar on some lenses will slip, thus causing the focal length to change, when the lens is pointing straight up or straight down. It's easy enough to fix -- simply roll back the rubber sleeve on the collar and tighten the screw. (...)
And was colected from the Pentax Discuss discussion group. Is there someone called Bill Peifer on this list?
