It's the worst lens I every used. I was so unimpressed by my RB lenses (50, 90, 180 all C versions) that I sold my whole kit. I may have just stumbled on some poor samples of these lenses. The RB is a great system camera, but my lenses left me looking for sharper and higher contrast options (just my particular taste in things). On the other hand, I've seen some very wonderful images made with the RB. To each his own . If you prefer really sharp, you'll have to look elsewhere. The RZ lenses, for example, are much sharper generally. I'm not sure if you can use RZ lenses on the RB though.....