Hi all, I've come across a whole range of old Tamron lenses and wondering where is the best place to get an adaptor ring for a Nikon mount (D5000); if it all possible and play around with them. Partial history - these are older Tamron lenses (circa early 80s, late 70's) which originally were used on a Konica SLR. Most of these lenses are attached to an adaptor for the Konica mount which I presume back in there day they were universal lenses which one just used the appropriate adaptor for your camera. Anyway, the glass are in great shape and I am curious to try them on my Nikon. There is a 500mm lens in the collection which I am really eager to try. Any ideas and pointers in the right direction is greatly appreciated.