I have a 'locating' problem with one of my lenses.

The lens cannot be turned all the way around to "4 O'Clock" on my T-90 body. This means that the the silver buton that normally pop us when the lens is located properly stays depressed.

The camera will still take shots - although the lens will not focus on infinity.

Any help would be much appreciated.

-- Mark Drinkwater (mark_drinkwater@hotmail.com), January 22, 2001

Answers

Hi Mark,

I would say the lens is damaged. (Is it a 28-85 f4 by any chance?) When canon went to the bayonet mount and redesigned the lenses to suit, they became much weaker and more susceptible to impact damage, usually with the lens breaking apart just ahead of the mount.

I would very carefully see if there was any play at all in the lens ahead of the mount and if so see about repairing or replacing the lens. Some parts are still available from Canon and it may be recoverable. Also, some lenses were damaged and just glued back together and were subsequently unloaded.

If the lens it still solid, there may just be junk in the mount. If you are handy with tools, you could the shiny mount ring out and clean it. Just remove the 3 or 4 screws holding it into the black body and see if there's any crud in there. If you fear nothing, you can go further, and take more apart but you may quickly find lots of strange little pieces.

The body isn't in stop down mode during the lens change is it?

Less likely is that the mount on the body is loose and has to be re- tightened. I think I left a procedure to do that on one of the previous postings here.

Cheers,

Duane

-- Duane K (dkucheran@creo.com), January 22, 2001.