I've had a run of bad luck trying to find a really good (and budget priced) portrait/long lens. Three Leica R 90 2.8 Elmarits had to go back to the sellers due to haze and fungus. Focal Point wants a fortune to clean these things (although I'm sure it's worth it, as John knows what he's doing). I then tried the Canon FD S.C. 135 2.5 and an R 100 2. Both are outstanding, and the 135 is truly a great lens for so little money, but I really don't like FD mount cameras. The F-1 is too big and heavy, and the A series cameras feel and are cheesy. The two AE-1 P cameras I bought were squealers too. Having a top shutter speed of only 1/1000 is also an issue, and the F-1's 1/2000 alleged speed is mitigated by age, as it really tests out at 1/1000. No shooting wide open in the sun w/ my Tri-X. The last lens I tried was a Nikon non A.I. (ai'd) 85 1.8 lens. Oh, it's sharp and the build quality is superb, but it's pretty soft at 1.8. That's no big deal as it's fine at 2.8, but I am not impressed w/ the bokeh and IQ. There were shots that had some very unattractive hexagonal highlights. I guess many years of shooting Leica R glass has spoiled me. I want smooth, and no weird stuff in the background. Having lost a bundle on ship back fees on the Leicas, I'm done w/ them. I'm currently thinking of one of those Rokinon/Bower/Vivitar 85 1.4 lenses, or a Pentax 135 2.5 in m42 mount, which will fit my Nikon w/ a cheap adapter (stop down mode). The Nikon is the smarter way to go. $20 got me a N8008s w/ spot metering and 1/8000 top shutter speed. Deal of the year if you ask me. So, is there a LOT of difference between the various versions of the Pentax 135 2.5 lenses? Everyone says to get the SMC version, but the prices are considerably different.