Sigma 30mm backfocusing

Yesterday I received my new Sigma 30mm from Unique Photo, it replaced my 35mm f/2 that I sold a day earlier. Regular free shipping took just overnight. Very impressive!

However, I did a lot of testing today, in bright daylight, and it is distinctly backfocusing, particularly at 1.4 and 2.0. It is very sharp starting with 2.8. Those who had an issue with a Sigma - is it better to just send it back for a replacement, or to send it to Sigma for calibration? What is your experience with Sigma service? I tried to call Unique Photo, but while they work on weekends, these guys have customer service working only on weekdays.

Send it in to Sigma.

I'd have Unique arrange for it to be sent to Sigma for calibration.

Send it.

Send back to sigma. It's very hard to find a good new copy IMO lol.

skywalkee wrote in post #13491065
Send back to sigma. It's very hard to find a good new copy IMO lol.

very true..

Sigma will take care of it.

I decided to give it another try. Unique Photo was every good, I sent a request for replacement yesterday, today I had the return shipping label in mail mail. The customer service guy there told me the same what most of you do, that I would be better off to send the lens to Sigma for calibration. If the second copy is not sharp as I expect it to be, this is what I am going to do.

The only problem that they ran out of stock, and it willbe some time next week before they get re-supply!