Sigma 30 - buy new or known used good copy?

I'm thinking about buying a Sigma 30 1.4, but am worried that I may get a copy that needs to be sent in for adjustment. Would it be better to buy a used copy from a reputable seller that confirms they are selling a good copy? They come with 10 year warranties, right? Assuming it is just a few years old, I should still be able to send it in and have the labor be covered.

Just to give you perspective - my Sigma 30mm worked fine on my T1i and older 40D perfectly, but needed adjustment (MA) on my 7D and my friend's 5D2. However, it worked fine on another friend's 5D2. Different cameras/lens combo can give different results.

So, to answer your question, buy one with the warranty - just in case you need to send it in for calibration. If buying used, make sure there is a receipt, or test the copy on your camera body first.

Thanks Hieu, that answers my question. I'll probably buy new then.

"Known good" only applies if it's known good on your own body. Best is to try it in person. If you can't, I'd go new (the cost difference is about 20%, not all that much) and make sure you can return it.

In my experience, a given copy of this lens can focus differently on different bodies. I would only buy used if I was getting a copy of the receipt.

I'd definitely get one that has a long warranty left.

I just realised my lens has front focus issues at moderate to far distances after having it for 6 months. I was mainly using it at close distances most of the time so I didn't realise this problem. I'm taking it to the service center today.

Thanks for asking Eaglefan. I had the same question in mind.

Amazon has it new for 10% off through the 16th or 18th (can't recall exactly) I believe, makes it $390 US, which isn't too much more than the used price, so I say might as well get the full warranty out of it.

Get a body that has AF micro adjust.

gasrocks wrote in post #11613268
Get a body that has AF micro adjust.

I would like a 7D but can't justify the cost right now.

Tigerkn wrote in post #11613229
Thanks for asking Eaglefan. I had the same question in mind.

Sure thing man.