Auto Focus Issues 28-135mm IS USM on a 7D

[Iggythetiggy]

I understand that this topic has been rehashed to death but my issue is a bit different. Camera is a Cannon 7D. I picked up a lens from a good friend fellow photographer that other than the camera body all my current lenses were his first lenses. Right now I just picked up a EF 28-135mm f/3.5-5.6 IS USM from him, to give me a decent mid range lens for my bag. At first I thought it was just an issue past 70 mm where it would just continue to hunt for focus. Even in One Shot, Center spot focus it will just sit there and twitch between infinity and 50 feet on the dial. At full zoom it will sit and bounce in the infinity range never actually locking on to focus. If I touch the focus ring and move it, or nudge it it will sometime lock but it will be far from focused.

I set up my big tripod, white sheet backdrop and a solid object (Clay Frog) non reflective about 10 feet away. I lit it with a lamp. I set the lens on it's minimum zoom, camera is in P mode. I turn on live view and using the zoom on live view get as close to the object as I can get zoom wise via the live view. Lens is still at 28mm. I hit the shutter half way and zip zip beep. About a 1/8 of a turn out of focus. I swap to my 18-55 and zip zip in focus. So it's definitely a lens issue, even my Tamron 70-300 focused sharp at all points. Swap back to the 28-135 and it won't focus. I can put it in manual and get a super sharp image and a beautiful picture.

I have reset the camera a few times as originally something I changed left the stabilizer on all the time. So the camera other than my custom settings for the C Modes have been reset.
I have carefully blown out the inside the best I can of the lens with a bulb, and have verified the front lens is not crooked.

Friend has offered me a full refund for the lens but it's a 2 hour plus round trip again to get it back to him. Am I missing something or unbeknownst to him since the lens sat a few years sadly without a rear cover on did something happen internal and it's not worth the hassle to have it fixed? I paid $80 for the lens which I thought was fair as most are going $100-120 on eBay right now. I have a gig Saturday I guess I'll be shooting in manual focus now. Be taking 1000+ photos and auto would be really nice.

[Stephen]

Hi Iggythetiggy,

You absolutely qualify for the Upgrade program! Give them a call to get details before sending your lens in, just so you have the best info to make a decision.

Also, a clean and check (Canon Maintenance Service) here at Canon is super cheap - they'll make sure your camera is nice and clean, inside & out, and all the buttons work like they should. It's not an outright repair, but it's maintenance that we recommend for all cameras periodically.

When you go to the link above for repair, it'll give you the details for clean and check too! The site will lay everything out for you in advance, BUT, if you have questions, our people are super friendly, and are happy to help! 

[Iggythetiggy]

Honestly it's why I bought it it already looks brand new. Just had a bit of dust inside the body from the previous owner. But it's been something even the tech at Shutterbug recommended. Amazing where dust can find it's way into even with proper care. My old FSLR got dust into the eyepiece and I had always been super careful. It's on my list to get done now. I picked up the body for a great price well under the recommended msrp used. $300+ less than B&H wanted.

[RobertTheFat]

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@Iggythetiggy wrote:
Honestly it's why I bought it it already looks brand new. Just had a bit of dust inside the body from the previous owner. But it's been something even the tech at Shutterbug recommended. Amazing where dust can find it's way into even with proper care. My old FSLR got dust into the eyepiece and I had always been super careful. It's on my list to get done now. I picked up the body for a great price well under the recommended msrp used. $300+ less than B&H wanted.

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The fact that you got a 7D at a great price is all the more reason to keep it in top condition. The one downside of interchangeable lenses is that dirt can get into a lot of obscure places, and getting it out has to be done very carefully. I have a couple of 7D's and a few other Canon cameras (including a couple that belong to my wife), and we try to have each one and its lenses cleaned at least every couple of years. If you live in the eastern half of the U.S., I recommend the Canon repair shop at Jamesburg, New Jersey (about five miles from Exit 8 of the NJT). They do a good job and do it very quickly; I've dropped off cameras there around noon and had them arrive at my house the next day.

[Iggythetiggy]

Thanks for the tip. I'm on the west coast north of Seattle. Cannons main repair facility in California is actually the closest center. I fiddled with it a bit more. Cleaned the contacts with a bit of contact cleaner and I got it to quit hunting as bad and now it locks focus at any zoom level but it's still far from being sharply in focus. So I'm now to the point of believing it's out of calibration or maybe the lens got dropped at one point. Will get thru this weekend using my old EFS 18-55mm that came with the old eos rebel.

[kvbarkley]

You are the first person to indicate that cleaning the contacts made any change whatsoever!

[ebiggs1]

"You are the first person to indicate that cleaning the contacts made any change whatsoever!"

 I can't remember the last time I ever heard cleaning the contacts worked or helped.  Yet people will clean away and sometimes with destructive methods.

 It appears now, it didn't help here either.

[Iggythetiggy]

I just tried a few other things swapping lenses and I think I figured it out. Where both my 18-55 and 70-300 will have a coarse move and a very definite fine adjust in auto the lens in question is only doing rapid coarse adjustments. Sadly the lens went back to hunting in short order. It locked perfect focus 1 time in about 50 tries. Batteries are exhausted now (have a battery grip) so I'm done messing for now.

[Iggythetiggy]

And another thing I discovered and it triggered a lens error on my screen is the F Stop is holding wide open, setting the F/Stop at any level and hitting the side button to view the setting does not trigger the shutters to move. So in the lens will come im sure it's a bad lens now sadly. And my guess is if the Shutter for the F/Stop is not functioning that could be the issue why it's having an issue focusing possibly?

[RobertTheFat]

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@Iggythetiggy wrote:
And another thing I discovered and it triggered a lens error on my screen is the F Stop is holding wide open, setting the F/Stop at any level and hitting the side button to view the setting does not trigger the shutters to move. So in the lens will come im sure it's a bad lens now sadly. And my guess is if the Shutter for the F/Stop is not functioning that could be the issue why it's having an issue focusing possibly?

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Shouldn't be, because focusing is always done with the lens wide open. That's the point of the button beside the lens - to let you see what your actual depth of field will be, because the aperture blades normally stay open for focusing. You wouldn't want it otherwise, because the more light that gets in, the more accurate the focus will be.

But if that button doesn't work - i.e., doesn't stop the lens down - that's a bad sign, because if something is sticking, the camera probably won't get the lens to stop down either. If that's what's happening, most of your pictures should probably be overexposed, because the camera has to assume that the stop-down mechanism will do its job. Is that what you see? If not, you may be looking for the problem in the wrong place.

If the mechanism is sticking, corrosion would have to be the prime suspect, and that re-kindles my suspicion that the lens may once have gotten waterlogged.

[Iggythetiggy]

I will be sending both in together. Did my event Saturday took about 1800 photos and the 7D didn't miss a beat. Being outside taking pics of moving kids and adults I set my iso at 800 speed and the camera in P mode. Ran my old 18-55 with a circular polarizer as we were on the bay park and the sun came out. I was in single pic mode but had the focus on full 19 point AF and after getting home looking at the pics on the screen on the camera all looked good. For home and opened up on my monitor then to my 32" TV and most were a hair out of focus. Was not happy with my initial outing for a huge event like this was. Even with the smaller lens it was wanting to randomly grab focus in frame and usually it would opt for a more distant focus lock then the object in the center. Even switching to spot center it was having a few issues. The other photographer at the event also had a Cannon one of the Costco package deals I think, 500 something with a lot of letters. Tried the lens in question and it was doing the same as my camera. She borrowed my 75-300 for a while as well as my Tulip for her 28-135 that worked flawless in mine. So it's definitely a lens issue but my 7D needs a serious professional inside clean.. thanks for all the input and I'll get a service ticket started. Big question is how does everyone ship it. I figure I want some serious insurance on the package and double or triple boxed wish I still had access to expando foam boxes. I have never shipped this fragile of an item before and I don't want whoever to destroy it getting to California.