Amazingly sharp even wide open: http://www.donsauction.com/pdml/Kitty.htm
Rather poor flare resistance: http://www.donsauction.com/pdml/Flare.htm (At least wide open, haven't tried the other apertures yet) I shoot wide open a lot so the sharpness is a good thing. The low flare resistance surprised me though. The supplied (correct) hood helps but it needs more. Handles very well, a pleasure to use once you get used to the long focus travel. (About 200 degrees) Those who own the SMCP 135/2.5: Is flare resistance in the K version better? Is focus travel as long? Don
