Sigma 30mm focus testing

I just bought a sigma 30mm and want to test it since there were so many people saying there are issues.

Does anyone have experience in these tests??
I am following these instructions,
http://focustestchart.​com/chart.html


After testing a couple of times it seems the left side is ok but the right side is front focusing.

Is that possible that one side is fine and the other off? Or am I doing this wrong?
What is an acceptable range of front focus that is within lens tolerance?

Lexar wrote in post #14988452
I just bought a sigma 30mm and want to test it since there were so many people saying there are issues.

Does anyone have experience in these tests??
I am following these instructions,
http://focustestchart.​com/chart.html

After testing a couple of times it seems the left side is ok but the right side is front focusing.

Is that possible that one side is fine and the other off? Or am I doing this wrong?
What is an acceptable range of front focus that is within lens tolerance?

Yes, it's possible.

What do real world shots look like?

I don't test or measure lenses. I find it a waste of time and it just drives people crazy. If I notice a problem when actually used then off to the vendor or manufacturer it goes.

-F

Sounds like a decentering issue and I would return the lens for another copy if so. Post the examples so people here can back your thoughts up.

Here are some example..

I only have 15 days to return it so during the week I did not have time for "real word" examples. That is why I am doing all these test charts.
However this weekend I will take it out and really use it.

However based on the test charts the right side seems to be focusing more forward then the left side.

That's not right at all. I'd return it and ask for another copy.

I would try to take a close photo of a person, with AF on the eyes. Use center point AF.
If you shoot a brick wall from a distance of a couple of feet, and the camera is lined up properly on a tripod, both sides should be equally sharp. If not, the lens could be decentered and needs to be returned.
This is what the photo above suggests. Both sides should be sharp with the sharpest point on the letters reading "focus here."

Rather than trying multiple copies. paying for shipping back and forth, wasting time- just send it to Sigma for calibration and be done with it.

Almost all users that have done this report getting back a stellar performing lens.

adamo99 wrote in post #14991125
Rather than trying multiple copies. paying for shipping back and forth, wasting time- just send it to Sigma for calibration and be done with it.

Almost all users that have done this report getting back a stellar performing lens.

This isn't a calibration issue though, its a decentering. I would think that would be a more difficult repair that may have to go back to Sigma in Japan, but I am not sure. Plus depending on where he bought it from, he may not have to pay shipping costs. I didn't have to pay for a replacement when I bough through Adorama for instance.

Thanks for the advice!

To return it to the store I need to pay shipping and then have them send me a new one and gamble that its better. Or I can pay the same shipping to Sigma to have it fixed or they might not be able to?

Which is a better idea?

If it were me, I'd return it to the store for another copy.
I was concerned about the problem you are having, and that is why I got the Canon 35F2.
If the next 30F1.4 isn't quite right, you still have the option of sending it off to Sigma, or asking for a refund.
Centering problems are not so easy to fix.
Sigma will often be able to fix problems when stuff is off. Years ago, I got a Sigma 50f2.8 macro lens (Minolta MD mount) that overexposed so much that there were no images on the film. This was a long time ago. They fixed it properly - it came back fine.
My current Sigma 50f2.8 macro lens works great on my crop bodies.

FEChariot wrote in post #14991467
This isn't a calibration issue though, its a decentering. I would think that would be a more difficult repair that may have to go back to Sigma in Japan, but I am not sure. Plus depending on where he bought it from, he may not have to pay shipping costs. I didn't have to pay for a replacement when I bough through Adorama for instance.

Perhaps, but it's still something that Sigma can, and will, fix. Who's to say the next lens he gets from the retailer isn't another dud. Send it Sigma once, and get it fixed properly, and live happily ever after.

adamo99 wrote in post #14993651
Perhaps, but it's still something that Sigma can, and will, fix. Who's to say the next lens he gets from the retailer isn't another dud. Send it Sigma once, and get it fixed properly, and live happily ever after.

I know what you are saying and if it was a simple calibration issue, I am sure they would fix it locally (not sure where the OP is from so I'll just say locally). With a more complicated repair like decentering, I fear that Sigma will ship it off to Japan (again assuming that's not local for the OP) and the OP is without a lens for several weeks if not months. It would be really good info if someone who actually sent off a 30/1.4 with a decentering issue would chime in and lets us all know what the turn around time was.

I'm in Canada so shipping to Japan and waiting for repairs is not going to be that fast!

I took the lens out yesterday to Tennis at the Davis cup and it produced amazingly sharp pictures. Stopped down to f2 they were very sharp. At 2.8 amazing! I even got some sharp ones at 1.4 as well. However the distance was a couple of feet so it would not see the issues from the focusing above since the DOF would be much bigger.

However I really bought this lens for low light and closer distances.. so I would need f1.4 and close proximity so I think I should still send it back.

These were taken at f2.8

Here is one that was about 6 feet away from me at f1.4

^^. If you're in Canada, even better- Gentec does a great job of turning these around really quickly. If they can't repair it, they'll replace it with a good one. They're in the Markham area (GTA).