Question: What Japanese brand-name lens was used between 1940 and 1980 by the German camera company founded by Ernst Leitz?
Sentence (from "Rokkor"): The name was derived from the name of Rokkō (六甲山), a 932 m high mountain, which could be seen from the company's glass-making and optics factory at Mukogawa near Osaka, Japan.
Relevant evidence: No