http://www.photozone.de/pentaxq/688-pentaxq85f19?start=1
Well, the distortion is really "extra-ordinary" for a prime! The diffraction comes into play for anything beyond f/4! (This was what I "predicted" long ago!) The most interesting thing on PZ part is that the LW/PH figures are not published anymore, as it is just about 70% as good as the micro-4/3 as briefly and vaguely told but yet it is still marked good to excellent in the "IQ" charts for "better" representation.. >:-[
At the same time, I'm afraid that the quality and reference value of the PZ lens test reports are also degenerating, with the introduction of such an "improved" less-embarrassing resolution rating system (to some manufacturers)! :-o Klaus, what do you think? (Of course, you do have some good reasons of your own to do so, don't you?)