Sigma 30mm 1.4 & 550D Focusing Problem?

First off sorry if this is in the wrong section.

I recently purchased a Sigma 30mm 1.4 for my 550D and have noticed a problem with the AF while using the viewfinder and liveview for focusing.
For some reason using the viewfinder i will chose my focus point, focus, camera beeps, take the photo, and it will come out soft and oof. If i switch to liveview and do exactly the same the picture comes out much better and in focus where i wanted it to be. Here are 2 examples both on tripod taken earlier today;

Viewfinder:

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Do you have links to full/original files with EXIF? Are they both @ F/1.4?

Based on those images it certainly looks to be front-focusing. LiveView wont have the problem because it just adjusts until max contrast is reached. Sorry to hear. You'll probably have to send it to Sigma to get that fixed. Personally I wouldn't buy a lens that fast without a body with MA.

Thanks for the reply, both were shot at 1.4. Both are on flickr, ive made them public so you can view the exif data and large versions;

http://www.flickr.com …6885889339/in/p​hotostream

http://www.flickr.com …6885894341/in/p​hotostream

If you want i can post direct links to the original size.

I spoke with Sigma Tech Support about a focusing issue I was having with a Sigma 10-20 on a 60D and was told Sigma lenses have a more difficult time with focusing on Canon bodies and if you want the sharpest shots you will need to get the lens calibrated to your body by sending the pair into Sigma New York.

Thanks for the replies, i purchased the lens from Amazon i think im going to return it and ask for a replacment and just hope the next one i get doesnt have this issue.

I would send to sigma for calibration. Another lens doesn't mean it will focus well. Or buy from local person where you can check the lens before hand.

DaveKosiba wrote in post #13907305
I spoke with Sigma Tech Support about a focusing issue I was having with a Sigma 10-20 on a 60D and was told Sigma lenses have a more difficult time with focusing on Canon bodies and if you want the sharpest shots you will need to get the lens calibrated to your body by sending the pair into Sigma New York.

That's interesting I did not know that. Why would they market a lens made for Canon and then admit they have a difficult time focusing?

Hawky wrote in post #13907442
Thanks for the replies, i purchased the lens from Amazon i think im going to return it and ask for a replacment and just hope the next one i get doesnt have this issue.

It may be better for you to calibrate the one you have. Or return your lens, get a refund, and buy a used copy from a member here. It is likely that your next copy will have the same focus issue. There are quite a few threads that revolve around this particular subject. Some members have gone through as many as 4 copies before ultimately giving up and calibrating their lens or just getting the Canon equivalent. I say all this to hopefully save you time and grief from playing the Sigma "lottery".

I do believe that Sigma makes great lenses, it's just difficult to get a good copy.

I may as well post here too. I'm going through this same issue and have posted about it in a few other threads too.

I think I'm going to just send mine in to Sigma.

I have called Sigma three times, asking whether or not I need to send the body in as well. It's difficult to get a solid answer from them, but it sounds like they can calibrate the lens either way, but will probably get better results if you send in the body.

One person did ask me if I was only going to use it on one body. If using more than one body, it's probably better to just send in the lens alone. Since my wife may use it on her camera at some point, and because I don't like the idea of sending in my 50D, I am planning to just send in the lens alone.

Also - each person I spoke with highly recommended sending it by FedEx or UPS. They said they generally don't have very good luck with the post office.

Jason

Again thanks for the replies, ive actually spoken on the phone to Amazon and they said they are happy for it to be returned and send a replacement, so im going to try that once. If the new lens that comes has the same issue then i will have to find somewhere that sells it locally so i can test it on my body before purchasing it.

Such a shame as i really do love the low aperture and focal legnth. Hope i dont have the same problem with the next lens!

Hawky wrote in post #13908272
Again thanks for the replies, ive actually spoken on the phone to Amazon and they said they are happy for it to be returned and send a replacement, so im going to try that once. If the new lens that comes has the same issue then i will have to find somewhere that sells it locally so i can test it on my body before purchasing it.

Such a shame as i really do love the low aperture and focal legnth. Hope i dont have the same problem with the next lens!

That's what I loved from amazon.excellent customer service. I suggest you buy used if still can't get good copy to avoid picking bad apples.
Good luck!

Does anyone know what the repair success rate is if you send it in to Sigma? How many people have sent it in and was unable to have Sigma properly calibrate the lens? I already tried one copy of the 30 that front focused and have another one on the way, but if it doesn't work I'll probably send it in to Sigma. I'm afraid Sigma will be unable to calibrate it properly and I won't be able to return it to the retailer.

I sent mine in and it came back fine.

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nu8reed wrote in post #13908968
Does anyone know what the repair success rate is if you send it in to Sigma? How many people have sent it in and was unable to have Sigma properly calibrate the lens? I already tried one copy of the 30 that front focused and have another one on the way, but if it doesn't work I'll probably send it in to Sigma. I'm afraid Sigma will be unable to calibrate it properly and I won't be able to return it to the retailer.

This is what prompted me to send my lens back to Adorama in exchange for the Canon 50 f/1.4. For every success story in calibration, there was a counter story about how calibration didn't really fix much, if at all. To me that was enough to exchange it.

Maybe the success stories don't post as much(too busy enjoying their lens! ), but when you average all the reviews from all the threads about this subject and the results are 50/50, compounded that it's riskier for cropped cameras, I'd rather go with the older technology on this one.

I will say that I sent my 17-50 OS lens to Sigma for calibration and I had it back in less than a week. More importantly, the lens went from awesome to simply amazing. I wasn't having any major focusing issues as described here but I figured for the money it cost me to ship it, it was worth having them calibrate. I was right.

But yes, you have to send your body in with it.