This is not intended to be a this vs that post....... The "pre-asph" 50 Summilux (version II and III) is a lens that's been seducing me for a long while, but I've yet to pick one up. I've shot a lot with the V4 35 Summicron, but have never had an M 50 that satisfied me. Not to say that the current 50 'cron isn't phenominal, I just need the extra speed of an ~f/1.4 lens , and have so far screwed around with less costly fast 50's (like the 50/1.5 Serenar, and the 50/1.5 Nokton-which is nice). I really have one question though, and that is how is this lens (the 50 pre-asph M Summilux) for central sharpness, wide open? My favorite 50 ever is the Pentax 50/1.4 (any multi-coated version will do!), and aside from barrel distortion, that is one fine lens. So, I am left to wonder, simply as a point of reference, is the M 50 Summilux sharper, wide open, than a very good SLR 50/1.4? Again, I'm not looking for which is the better lens: I think I can assume the Summilux will have higher overall contrast, and perhaps my Pentax 50/1.4, or a Canon EF 50/1.4, will be similar in overall sharpness, but does the 50 'lux offer more visual impact, wide open?