Canon EOS 700D autofocus issues

[gezamile]

Hello Everyone,

I have a 700D camera with a Sigma Canon 18-200/3.5-6.3 DC OS HSM II lens. Since some months during photoshooting the autofocus stops working. I have to power off then on the camera (without removing the battery) and it is working again fine for a while. It is very annoying because I can easily miss a good moment during an event. Do you have any idea what could be the issue? The firmware is up to date (1.1.4)

Thank you,

Regards,

Geza

[RobertTheFat]

Sigma and Canon are two separate and distinct companies, and your lens sounds like a Sigma. Sigma has to reverse engineer Canon's communication protocols between the camera and the lens, and sometimes they get it wrong. In order to rule out that possibility, you might want to try your lens on another Canon camera, preferably one of the same model. If it still doesn't work, you'll probably have to seek help from Sigma.

[kvbarkley]

Or contrariwise, check your camera with a Canon lens.

You might also wipe the lens contacts with a microfiber cloth.

[kvbarkley]

You might also check to see if *Sigma* has a firmware update avaialble. If you are lucky, this is one with the USB dock, if not you have to send it back to Sigma.

[TTMartin]

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@RobertTheFat wrote:

Sigma and Canon are two separate and distinct companies, and your lens sounds like a Sigma. Sigma has to reverse engineer Canon's communication protocols between the camera and the lens, and sometimes they get it wrong. In order to rule out that possibility, you might want to try your lens on another Canon camera, preferably one of the same model. If it still doesn't work, you'll probably have to seek help from Sigma.

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As far as I know Sigma does have a 4 year warranty on their lenses. So if you bought the lens new from a Sigma authorized dealer it should be covered under warranty. 

[ebiggs1]

"Sigma Canon 18-200/3.5-6.3 DC OS HSM II lens"

This is not one of Sigma's best offerings in a super zoom lens.  It or any lens that has a 11 to 1 zoom ratio is going to have problems from time to time.  It may be that you are asking it to focus in situations where it simply can't.

I only played with one for a short time and saw some problems getting it to AF at times. A f-ratio of f6.3 requires good light and contrast. If either is missing it may appear that the lens is not working when it is.  It just can;t achieve AF.

Good advice to try a real Canon ef-s lens on your camera to verify it is working properly.  Cleaning the contacts rarely to never works unless you have reason to believe they got contaminated.

Sigma customer service is better than it used to be so contact may be in order. As I recall this lens is not firmware upgradable at all.  Maybe Sigma can do it but you can't. When you confirm the T5i is working correctly, get in touch with Sigma.

[gezamile]

Thanks for your suggestions. What I experienced over the weekend that I don't have to switch off then on the camera to get the autofocus work, it is enough to switch to live view mode then back and the autofocus is working again. It is strange...

Could it be still the lens? The good news is that I have 2 more weeks before the warranty expires, but the bad news is that I need it back not later than next Friday because I will be travelling to Italy. Unfortunately Sigma needs the 700D body to test it, because they don't know what could be the issue. I'm not sure if they can send it back to me within less then two weeks...

[RobertTheFat]

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@gezamile wrote:

Thanks for your suggestions. What I experienced over the weekend that I don't have to switch off then on the camera to get the autofocus work, it is enough to switch to live view mode then back and the autofocus is working again. It is strange...

Could it be still the lens? The good news is that I have 2 more weeks before the warranty expires, but the bad news is that I need it back not later than next Friday because I will be travelling to Italy. Unfortunately Sigma needs the 700D body to test it, because they don't know what could be the issue. I'm not sure if they can send it back to me within less then two weeks...

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What you're saying, in effect, is that you don't have time to help Sigma debug their product. Return it and buy a Canon lens.

Alternatively, rent a (Canon) lens for your trip and deal with the problem when you get back. Of course that will require Sigma to show their appreciation for your assistance by stopping the clock on your warranty.

[ebiggs1]

" I'm not sure if they can send it back to me within less then two weeks..."

I would almost guarantee you that will not happen.  But a malfunctioning lens is no good.  Especially for a big trip.  Drop the dime on a real deal Canon lens and deal with Sigma after you get back.  Look what is at stake here.  Is it worth the risk?  It would not be to me. IMHO, I would not rent a lens to take out of the country. Get the extra insurance if you do. But that will increase the cost so buying a Canon lens is more attractive, IMHO, of course.

Folks seem to like the Canon EF-S 55-250mm f/4-5.6 IS STM Lens a lot. I don't own one and have never really used one besides at the store so I am not a real authority. I would much rather see you buy this lens, though.

If you contact Sigma right now, it should save your warranty.  Even if it is past the time limit when you actually use it.

[Waddizzle]

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@gezamile wrote:

Hello Everyone,

I have a 700D camera with a Sigma Canon 18-200/3.5-6.3 DC OS HSM II lens. Since some months during photoshooting the autofocus stops working. I have to power off then on the camera (without removing the battery) and it is working again fine for a while. It is very annoying because I can easily miss a good moment during an event. Do you have any idea what could be the issue? The firmware is up to date (1.1.4)

Thank you,

Regards,

Geza

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Make sure that you have sufficient light for the camera to focus, most especially when you zoom out to 200mm.  Also, if you have not done so already, set up your camera to use just the center AF point for focusing.  Ignore the rest of them.  The other points may not allow the camera to focus properly when you're zoomed out to 200mm [f/6.3].