I am very interested in adopting former East German Zeiss Lenses (lenses made for Pentacon) for my Hasselblad 201F. Does anyone know which of them are useable for Hasselblad. Someone offer me an 180mm/F2.8 Zeiss Jena. Does anyone know the quality of this lens, how does it compare to the Carl Zeiss CF 180mm/F4 offer by Hasselblad? How about other Zeiss Jena lenses then?