Originally posted by Seafood Example, daughter's birthday party yesterday. 5 or 6 kids sitting around while opening presents....most of their faces in focus, except the one all the way on the left side. Now that I think of it...seems like a left side thing predominately...but not always.
Post pictures of it. I can recognize it by now
Just want to make sure you're not hitting DOF issues.
You're basically looking for a photo where something on the left and right are equidistant from you and if one side is ultra fuzzy at that point, you have something called a "decentering issue". I had to send my lens back twice and my third copy is in good shape...
What was annoying was I couldn't see this all the time. I had to go on vacations where I shot a lot more before I'd notice it. Then send example photos on a CD to Sigma as proof.
No idea if their warranties are to the original owner or not, but I had to send the original receipt as proof of purchase...