When I buy a lens, I usually do the research and know what I'm getting. I have expectations. Most of the time the lens will pretty much meet my expectations. Sometimes I'm surprised though when I get a lens and find it is better than I though or more useful than I thought.
That lens for me is the Sigma 70 f/2.8 Macro.
I've been impressed with it's AF accuracy (I wasn't expecting much). I am impressed with it's sharpness (I expected a lot). I'm impressed with how useful it is as a general purpose lens. Oh, yea, and it is a great little macro lens too 
What's your story? Which lens has pleasantly surprised you?

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