Doug, I ran into that same anomaly several years ago. I solved it by reverse mounting a 28mm elmarit onto the front of a 180mm f/4 using a male-to-male "macro" ring. I had to use step-up rings to get the 28's filter threads up to 55mm. magnification was about 6.4:1. You leave the prime lens wide open and once you get the reversed lens focussed (HAH) properly, you stop it down for DOF, (about 1~2mm if you're lucky), but if you use an R5, 6, 6.2, RE, 7, 8 or R9, you can use the Nikon SC17, off camera cord and mount a TTL compatible flash on it and get a perfect exposure!! I think that's mighty nice of Nikon to have the same "pin" pattern and location as Leica R's & "M" TTL's. Hope this helps someone. Art Tafil