Help with lens

cinor · March 11, 2009

I purchased a used Canon 28-135 F3.5-5.6 IS USM lens to use with my Canon Rebel XT. I can't seem to get the auto focus to work on the lens. I read in the manual how to override the auto focus, but it doesn't mention how to return it to auto focus mode.

Any advise would be very much appreciated.

TIA

ziggy53 · March 11, 2009

cinor wrote:

I purchased a used Canon 28-135 F3.5-5.6 IS USM lens to use with my Canon Rebel XT. I can't seem to get the auto focus to work on the lens. I read in the manual how to override the auto focus, but it doesn't mention how to return it to auto focus mode.

Any advise would be very much appreciated.

TIA

Cinor, welcome to the Digital Grin.

There should be a switch on the side of the lens which allows or defeats autofocus. It should look like:

http://www.bristolcameras.co.uk/images/canon-lens-28-135-f3.5-5.6-is-usm-lrg.jpg

The switch in this image is on the left and towards the base of the lens.

ziggy53 · March 11, 2009

P.S. If you did not get a user manual with the lens you can download the PDF version of the manual from Canon here:

http://www.usa.canon.com/consumer/controller?act=ModelInfoAct&fcategoryid=149&modelid=7337#DownloadDetailAct

... under the "Drivers and Downloads" tab.

cinor · March 11, 2009

Yes, even though the switch is set to AF, it seems to either be overriding that setting or the lens is broken. :cry

I read in the manual that you can set it to 'Full-time manual focus' even when AF is set, so I'm hoping that's the case. I would like to set it back to the normal lens operating mode, where I chose the focus method using the AF/MF switch.

Thanks

Tee Why · March 11, 2009

In AF mode, you can always just rotate the MF ring and adjust the focus. If you switch the lens AF/MF switch to MF, no AF is available. This is what FTM (full time manual) is referring to, that even in AF mode, you can manually adjust the focus.

If you are having problems getting the camera to focus on the part of the image you specifically want, I'd recommend using the center AF point and focusing and recomposing. If you use all point AF and let the camera decide where to focus on, that may be the issue.

Good luck.

cinor · March 12, 2009

Thanks I'll try that

medinaphoto1 · March 12, 2009

cinor wrote:

Thanks I'll try that

Try cleaning the contacts on the lens itself and maybe also on the body. Sometimes they may get a residue on them and cause it not to work.

cinor · March 12, 2009

Thanks for the suggestions. Still not having any luck with it. I think it's time for a trip to my local camera shop.

Help with lens

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