EF-S Autofocus Problem

Hi Everyone,

I'm hoping someone can confirm what I'm suspecting - I should send this lens in for repair.

I have a Canon branded EF-S 17-85mm lens that's having a hard time locking the autofocus. It gets close and then just jumps between two points. I believe the lens is the problem, because it exhibits the same symptom on both bodies I have (Rebel XTi and XS.) Additonally, my other lenses don't have the same problem on either body. Manual focus on the problem lens works fine.

Can anyone speculate what might be wrong with it? Is it worth repairing? Should I send this directly to Canon for repair, or is there (in Canada) a best third party repair shop I should consider?

Thanks in advance,

I have actually seen another one of these do this. At the time I let the person borrow my 18-135, which worked perfectly. Any repair of a lens I would personally have done by Canon. That said, I am not sure it is worth the repair. The lens is discontinued and quite old. I would consider putting your money towards a newer lens with likely better image quality and performance.

Are you getting "Error 01" or "Error 99" messages?

I was getting error 99 messages during the summer, which is around the time the problem started. The mirror on the body was making odd noises at that time as well, but that seems to have since cleared up. I attributed the errors to the horrendous east coast humidity (probably not, but it made me feel better at the time )

Use it for a paperweight. Put the money toward a 15-85. I think you'll like the upgrade.

The EF-S 17-85 is notorious for it's aperture ribbon to fail over time. It was my first lens and the same happened to mine, it was intermittent. Sometimes I would have to turn the camera off several times to get the lens to function normally, then it would be fine for about a week or two. It only gets worse, it became a daily issue. Then the lens would not focus from ~50-85mm, finally it just quit focusing.

Some people managed to do the repairs on their own for less than $30 in parts. You should be able to find some DIYs on the boards if you do a little bit of searching.

About $130 for Canon to fix it. I'm thinking about a 18-135 STM for a replacement.