I understand that some Zeiss lenses are marked "Carl Zeiss Jena," others, "Jena," "ausJena," "C. Z. Jena," or something else that deletes the "Zeiss." This is, of course, due to a legal settlement concerning the division of Germany: only East-German lenses ended up allowed to use the name, "Zeiss." My question is, has anyone noticed a difference in quality -- of materials/workmanship or of results delivered by optics -- between like lenses of the two sorts. For example, has anyone noticed a consistent (not just between two random pieces) difference between West- and East-German 2/50 Pancolars? Thanks.