EF 75-300mm focusing sticks

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My EF 75-300mm lens won't focus at infinity because it sticks. It can be focused manually but these requires a fair deal of effort, and is too much for the AF. Presumably something needs cleaning - is there anything I can do, or is it a repair job?

-- Jan Witkowski (witkowsk@cshl.org), August 30, 2001

Answers

Jan,

If you've gotten sand or other debris in the crevices of the focusing or zooming rings it can make it difficult to turn the rings. Use of a brush (or very judicious use of compressed air) can be used to blow such debris out. However, it sounds like your situation is more serious, if you actually can't get to infinity. It sounds like the focus mechanisms are damaged & in need of repair. Was the lens dropped/knocked? Is it under warranty? Good luck to you.

-- Hung James Wasson (HJWasson@aol.com), August 30, 2001.


Jan,

I got your direct post. The conditions you complain of still worry me -- but I've had another thought. I had not known that you were in Costa Rica. Being equitorial, I imagine the heat & humidity must be feirce (my wife's been to Costa Rica, Honduras, Guatamala, Oxaca (& other states in Mexico), but I've not had the pleasure. :-)

Enough rambling! My thought is that the environmental conditions of high heat may have caused the lens housing to expand -- increasing the friction. That may not really explain why it only sticks at certain points, and would be totally shot out of the water if the problem persists in air-conditioned environs.

I'm still guessing it's broke!

-- Hung James Wasson (HJWasson@aol.com), August 31, 2001.


I had a similar fault with another lens it turned out to be a loose inside lens, man- repaired f-o-c,

-- steven Maskill (Steven.Maskill@excite.co.uk), October 03, 2001.

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