Lens Repair

Shakey

Well not so much a repair but a tune up.

Situation: My 35-105 Canon EF lens is a nice lens with sharper optics than the 18-55 Kit lens.
However when on auto focus it is slow and sporatically works,it fails 10-15% of the time and stopped working alltogeter when I was shooting outside at a warmer temperature. I am wondering if it is in need of a cleaning perhaps something impeads the motor mechanism?

Looking at it , I see screws to go look inside of it. I was wondering have any of you opened up your lenses and cleaned /lubricated them?

Any hints tips or cautions?


Tim

Shakey

Hmm no replies? I guess I am going were no man/woman has gone before...

Tim

pathfinder

Shakey wrote:

Well not so much a repair but a tune up.

Situation: My 35-105 Canon EF lens is a nice lens with sharper optics than the 18-55 Kit lens.
However when on auto focus it is slow and sporatically works,it fails 10-15% of the time and stopped working alltogeter when I was shooting outside at a warmer temperature. I am wondering if it is in need of a cleaning perhaps something impeads the motor mechanism?

Looking at it , I see screws to go look inside of it. I was wondering have any of you opened up your lenses and cleaned /lubricated them?

Any hints tips or cautions?


Tim

Tim - sorry for not responding sooner - the Canon EF lenses are fly-by-wire - by that I mean they depend entirely on good electrical contact with the little pins inside the lens bayonet- sometimes if they get oil or dirt on them, the lenses may not focus correctly or the camera maye even lock up and go on strike. It happened to me yesterday - I just dismounted the lens and remounted it and all was well. Sometimes carefully cleaning the little electrical contacts on the lens will help.

But if cleaning the contacts does not resolve the problem, I would send the lens to Canon for service especially if the lens were still under warranty. I would not let anyone else begin removing screws from my lenses but a trained Canon service person. But that is just me.

Shakey

The lens is 10+ years old . I took the screws out today and got a small peek inside . I put it all back and it still works the same so I might dive in further on my next foray.

pathfinder

Shakey wrote:

The lens is 10+ years old . I took the screws out today and got a small peek inside . I put it all back and it still works the same so I might dive in further on my next foray.

I gather your repair did not change the focusing problem then? Sounds like you are having fun tho.....

wxwax

Shakey wrote:

The lens is 10+ years old . I took the screws out today and got a small peek inside . I put it all back and it still works the same so I might dive in further on my next foray.

Yikes, you're a braver man than I. I would worry tons about letting dust into the lens. I've read some about focus problems with the 70-200 L IS, and the first responses were the same as Pathfinder's - clean the contacts. For quite a few users, that seemed to do the trick. I would assume they cleaned the contacts on both the lens and the camera. Maybe after all these years, the contacts are worn down?