A very similar issue with a used lens I purchased. Luckily Adorama was great and let me return it since it's rating didn't match the performance. Knowing others have have experienced the same symptoms makes me a little more cautious about purchasing one in the future. In the end I'll still buy one, no lens beats it for low light performance on a 1.6x body. For the less than a week I had it it was amazing. The price was the only hard thing to swallow.


Its an amazing lens.