Excerpt: I mainly do portrait photography, so I wanted to upgrade from the 50 mm 1.8 to this lens for a sharper, more accurate focus. Out of the box, this lens was not calibrated correctly to my DSLR and was front-focusing (making all of my photos slightly out of focus) so I had to take it to a camera shop for microadjustment. Now that it's calibrated correctly, it's great.
Excerpt: I'm a hobbyist and amateur photographer who just started taking photos. I've read good things about this lens and also read lots of good reviews. One thing I've had trouble with and have also read about was trying to shoot at f/1.4 in low-light situations (dimmed lit rooms). It seems to have trouble focusing on a subject at that aperature. But again, I'm an amateur. I may be doing something wrong or not doing something right.