Talking of the Nikon S-series rangefinder telephoto. The longest which was coupled to the rangefinder. It comes relatively cheap for a collector--$200 to 350 depending on the finish. It's extremely slim (Ø43mm thread) and has its own tripod screw mount, to help balance it with the S/SP's. The iris shows over a dozen blades. It's supposed to be pretty soft/low contrast wide open but had a good reputation if stopped down to f/5.6. Anyone tried it on :43:?