Published in Spring 1993 Zeiss Historica Journal
Author: Robert Pins
See Page 16 – 17.
The author amplifies an earlier article on the Magnars for the Rolleiflex TLR camera beginning in 1939 and adds additional information on the Zeiss Duonar from 1952. The later introduction in 1961 of the Tele-Rolleiflex with a dedicated F/4 Sonnar 135 mm lens would make these products less desirable.
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