The 85mm lens is a GORGEOUS focal length... I have one in my 'stable'... but its the Ultra-Achromat, the lens with only fluorite and quartz elements, that I have used over the years for UV and IR imaging. I is probably the 'sharpest' lens that Pentax ever produced for imaging... even within the 'visible' wavelengths. Unfortunately, with the demise of EIR film, it does not get used that much any more.

Ken