60D and backfocus on Sigma 17-50

Hi guys first time dealing with backfocus issues, I bought a pair of Sigma 17-50 F2.8 OS, and both lenses at 17~35 mm have back focus, one copy is worst than the other but both have back focus and also both at 50mm are spot on.

I must say that with my other lenses Sigma 10-20 F4-5.6, 100mm F2.8L and 40mm F2.8 I don't see any focus problems.

So this could be a camera problem or both lenses need to be sent to Sigma for calibration?

Unfortunately I don't know somebody here or have other body to test them.

Thanks.

I've never had a canon camera with focus issues -- and I've owned a couple dozen beginning with the original dRebel -- but the tales of sigma lens focus woes are legion and well-documented. And sigma does the "the dock" for a reason. I'd bet money it's your lenses, and I would never send my canon camera to sigma

Ignore the canon fanboy. he will offer you no help
Some lenses will have some issues. Happens with ALL of them from every manufacture. I have had multiple Canon 85 1.8 that all needed alot of Microadjusting as well as a few copies of the 70-200 F4 that needed its fair share of Microadjusting as well these are on 1D bodies and my 7DII. it seems these days since there are options in almost all cameras to do some fine tuning companies may have a little looser of a spec tolerance for lenses since we can adjust them a little at home to get them pretty close to perfect with the body we own. Since every body will have a little bit of variation from another. None are the same. but unfortunately your 60D does not have MA to try and adjust the lens a little to get it in. I would send the lens in for calibration. This is a lens I dont hear having this issue mush. my copy has been perfect out of the box. My Sigma 50 1.4 was having issue when i got it. MA couldnt get it in spec and it was very inconsistent. I sent it in and a week later had it back and now its AF is very good as it is very consistent in its focus and it just needed a tiny bit of MA when i got it back.

no one is talking about MA. we're talking about about backfocus, a common complaint from anyone who has ever played sigma lens roulette

yes and you would use MA to fix some back or front focusing. Just go back to your canon hut

never had to MA any Canon lens. Never had a canon lens backfocus or frontfocus. Sigma sells "the dock" for a reason.

well then move on since you are no help to him or really anybody

move on? I've got as much right as you to post here and you are the one that is provoking me. and it's not the first time. maybe if you used less problematic equipment you would be less uptight. photography should be fun. just saying :^)

sorry for the derail OP..but from my original reply to you. best bet send the lens to Sigma for a calibration since your body does not have Microadjust. best to put Ed on ignore since he will offer you no help

OP, why did you feel the need to buy 2 identical lenses?

ed rader wrote in post #18320811
I've never had a canon camera with focus issues -- and I've owned a couple dozen beginning with the original dRebel -- but the tales of sigma lens focus woes are legion and well-documented. And sigma does the "the dock" for a reason. I'd bet money it's your lenses, and I would never send my canon camera to sigma

Yeah I have read a lot of sigma back/front focus out of the box, I wouldn't have a problem buying the dock, but it's not compatible with the lenses i own

05Xrunner wrote in post #18320949
Ignore the canon fanboy. he will offer you no help
Some lenses will have some issues. Happens with ALL of them from every manufacture. I have had multiple Canon 85 1.8 that all needed alot of Microadjusting as well as a few copies of the 70-200 F4 that needed its fair share of Microadjusting as well these are on 1D bodies and my 7DII. it seems these days since there are options in almost all cameras to do some fine tuning companies may have a little looser of a spec tolerance for lenses since we can adjust them a little at home to get them pretty close to perfect with the body we own. Since every body will have a little bit of variation from another. None are the same. but unfortunately your 60D does not have MA to try and adjust the lens a little to get it in. I would send the lens in for calibration. This is a lens I dont hear having this issue mush. my copy has been perfect out of the box. My Sigma 50 1.4 was having issue when i got it. MA couldnt get it in spec and it was very inconsistent. I sent it in and a week later had it back and now its AF is very good as it is very consistent in its focus and it just needed a tiny bit of MA when i got it back.

Yeah I'm pretty sure that if the 60D had micro focus adjustment that will solve it...

And only the lenses need to be sent or the body also ?
And you did the process online or how was done the arrangement to send you lens?

Thanks.

Inspeqtor wrote in post #18321310
OP, why did you feel the need to buy 2 identical lenses?

An awesome deal, one is for me and the other for resale.

ed rader wrote in post #18321119
no one is talking about MA. we're talking about about backfocus, a common complaint from anyone who has ever played sigma lens roulette

I've played the roulette game (with that exact lens BTW) and I guess I won because I haven't encountered any issues. It's a wonderful piece of glass.

I see the OP is from "So Cal" and at least one authorized service facility is in San Diego. I recommend he give them a call, nothing lost and much to gain. See https://www.sigmaphoto​.com/service-support for contact details.

CyberManiaK wrote in post #18321417
And only the lenses need to be sent or the body also ?
And you did the process online or how was done the arrangement to send you lens?

Thanks.

I only sent the lens in

ed rader wrote in post #18321150
never had to MA any Canon lens. Never had a canon lens backfocus or frontfocus. Sigma sells "the dock" for a reason.

I'd bet you would benefit from some AFMA on at least one of your lenses if you ran Focal software on them all. FWIW, I need AFMA on my Canon 70-200/4 IS and 60/2.8 and I would bet some others would see benefit if I bought the Focal software but I am just not that fussy about to make it worth my time and money. My older Sigma glass including the 17-50 OS needsno adjustment.