Sigma 85mm lens
I just picked up this lens, and I have to say I'm impressed. I hear quality control is a problem, so I may have been lucky, but my lens seems to be awesome: no focus problems, almost no distortion, very sharp (even wide open), not soft in the corners, etc. It's amazing, really!
Only one problem: purple fringing. I was shooting on a sunny day, and when I took pictures of people in the sun in white shirts against dark backgrounds ... wow, was there purple fringing! I've never seen that much on any lens. Shocking really. No hope of removing in with the Lightroom 4 chromatic aberration checkbox. It disappears somewhat as you reduce the aperture, but not nearly as quickly as I hoped. And it's not noticeable except in extremely contrasty situations. But when it's there, it's horrid! (I'm at work, so I don't have a picture to post. Sorry.)
Given that everything else about the lens seems perfect, I have to think it's normal for this lens. But I wonder if anyone else has this lens and can comment on it.
I guess I shouldn't care too much, since I plan to use this lens mostly for studio portraiture. But I'm just curious.