I was wondering if there are years of production that are generally consider "prime" years that are sought after, specifically for portraiture. If so, feel free to elaborate.
36cm and/or 42cm focal lengths. Not necessarily the Universal, but your answers may encompass those as well, although I understand that the Universals did come out later.
I understand that this is a very subjective question (some prefer coated, others don't etc.). I am curious, though, of individual preferences and thoughts.