# EF-S 17-55 f/2.8 : possible issue?



## Maglor (Jun 16, 2014)

Hello folks. First post here. Hopefully you guys can solve my issue (or guide me towards a solution).

I've got the above mentioned lens for sale and a couple of days ago someone passed by to test it (and maybe buy it). Eventually she didn't buy it (for now), because she pointed out a rather strange phenomenon. Something that has never really occurred to me in the 3.5 years that I've used this lens.

When you focus on a subject the IS obviously kicks in. Apparently with this lens, the IS can generate quite some noise, but that seems to be quite 'normal'.

http://www.canonrumors.com/forum/index.php?topic=413.0

https://www.flickr.com/groups/canon_...7619031700221/

http://photography-on-the.net/forum/...d.php?t=807930

The thing that worries her (and myself as well now) more is that the AF seems to hunt a bit (somewhat as described here: http://www.dpreview.com/forums/thread/2975199). We took a bunch of pictures (in good light conditions) and almost always you can clearly see on the distance scale on the lens that it has to hunt a little bit. It looks like it focuses a tad too far and then jumps back, all very quickly. This generates a (small) shock effect. 

There is no difference if all focus points are activated or just the center one. We only tested it with her camera (450D). Mine is already sold so I can't test it myself anymore. . I believe that the camera was set up in "One Shot" mode (no AI Servo). 

We tested other lenses (EF-S 10-22, EF 70-300)as well to rule out a possible camera problem. They didn't have this issue.

Focussing itself goes quickly and never fails. The contact points of the lens are clean.

I was wondering if this kind of behavior is normal? Are there any tests that we can do to check if there's something wrong with the AF (or even IS)? Again, the lens always focuses correctly, but it seems to hunt a bit.

The lens is obviously out of warranty and I don't want to sell someone a pig in a poke. If there's really something wrong with it, I'd rather not sell it.

Thanks!


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## neuroanatomist (Jun 16, 2014)

*Re: EF-S 17-55 f/2.8*

I've noticed that faster lenses seem to do this on non-1-series bodies (5DII, 7D). Your comparator lenses were both slower than f/2.8.


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## Maglor (Jun 17, 2014)

So, you think I shouldn't be worried about this?

Anybody else experiencing the same issue?


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## tomscott (Jun 17, 2014)

I have owned the 17-55mm for 4 years. The IS is pretty loud but the AF is perfect snaps on very quickly. Ive used it on a 350, 450, 40, 50 and 7D and had no issues.

The only issues I've had have been dust and the zoom ring is a little rough, probably from too much use over the years.

Where were you focusing? was it somewhere with good contrast not some dark indoor situation with no light?


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## Maglor (Jun 17, 2014)

No, it was a mix of inside and outside shots, both in good light conditions.


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## sagittariansrock (Jun 17, 2014)

I have never seen this behavior on my 7D. Always snapped into focus first time.
I would test it on another camera- it might have something to do with the Rebel's AF system and faster lenses, as Neuro pointed out.


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## barracuda (Jun 17, 2014)

I tested my 17-55 on a 100D, 650D, and 60D. It always snapped into focus, at varying distances, on each of the cameras. No problems to report here.


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## Maglor (Jun 18, 2014)

OK. I'll try to find someone with a different camera and try it on that one, just to be sure. If I have the same behavior on a different camera I guess I'll have to send it in for repairs.

Thanks!


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## Maglor (Jun 19, 2014)

Update: I went to a camera shop today with the lens and was able to test it on a 650D. No issue whatsoever. The lens focused fast and perfectly. No 'overshooting' or 'hunting' issue, even though it was pretty dark inside the shop. Nothing wrong with the lens 

So I believe it must indeed have been a set up (or other) issue with the initial camera body.

thx everyone.


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