I was recently given a Durst F60 Enlarger. I set it up and everything is working very well! However, it did not come with a lens. I do already have an Emitar/S 4,5/80 lens. The thread screw on this lens is to big, and does not fit! What do I need to mount onto the enlarger so I can use this lens? Or is it easier to just get a lens that has the required M 30 thread screw?