Hi Marcus, I've a few Pentax 50mm lenses here - K55/1.8, K50/1.4, M50/1.4, M50/1.7, A50/1.4 - and I like them all. The M50/1.4 can be pretty sharp and quite good wide open, but the A is better, and so is the K, by a small margin, at least wrt light fall-off, contrast, and sharpness. However, these differences don't manifest themselves clearly until a large sized print is made - say about 16X magnification. In some cases processing choices can obscure the differences in sharpness and contrast, IOW's, they are quite close and can almost be used interchangeably.
There are some slight differences in fingerprints, but really, not enough to make a big deal about with normal sized prints. The K55/1.8 is, in many ways, the worst of these lenses, but sometimes I prefer it over all the others because of it's somewhat lower contrast and finer resolving of small details. If I were to recommend only one of these lenses, I'd have to go with either the A or the K, and would suggest the A as it can be used to its fullest potential with a greater number of cameras. If, however, use with newer cameras is not a consideration, the K would probably be my choice for general photography. Shel > [Original Message] > From: Marcus Murray <[EMAIL PROTECTED]> > To: <pentax-discuss@pdml.net> > Date: 4/16/2006 10:10:24 AM > Subject: K 50mm f1.4: My first post in 5 years! > > I have just picked up a nice MX and need to put a 50 on it. My old kit was a Spotmatic and an SMC 50/1.4, now stolen. I use this mostly to supplement my Leica M outfit, filling in the gaps between it's shortcomings, and as a backup. I'm interested in the early "K" 50/1.4 because it appears to be the nearest replacement to the lens I've been used to. > > The lens spends most of it's time wide open, close up, occasionally with a short extension tube. Ultimate sharpness is not my main concern. > > I'm interested to know what people think of the differances between the K lens and the M version, especially regarding overall wide open rendition. I remember some discussion in the past about this, but the archives don't seem to offer much help. I recall many people regarding these lenses as virtually identical, but a look at the cross sections would seem to tell a different story. > > Any thoughts?
