Posted: Sun Dec 22, 2013 9:51 am Post subject: |
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konicamera wrote:
Pontus wrote: |
Buhla.de writes that the 57/1.2 suffers from yellowing. I had two of these lenses, and the slightly older lens was a bit yellow but this one was perfectly clear and neutral. I wonder if Konica switched glass very late in the production run? |
Only the very early lenses seem to suffer from the yellowing. In my experience, all of them are lenses with the aluminum ring made from 1966 to 1970. They were followed by the all-black/all-metal version (1970-1974) and I have not seen any of those with yellow glass. Your lens is of the last version and that one was made from 1972 to, apparently, the end of 1979 (yours seems to be from October 1978). I've never seen yellow glass on the last version.
Based on observation, it would seem that the change in glass took place at the time when Konica introduced its new Color Dynamic Coating, the one with the deep blue color. Before that the color of the coating was amber. This took place sometime during the production of the first version. I have seen many aluminum ring Hexanons with either coating. Perhaps this took place in 1968, with the introduction of the first Autoreflex T.
As a curiosity, this also seems to have coincided with the switch from large capital letters on the front ring to a smaller, more discreet font. An aluminum ring lens with large capital letters on the front most likely has the old coatings and vice versa. |