Archived posting to the Leica Users Group, 2000/02/16
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]By the way, 1952 US Patent number 2,618,201 is far more interesting. That is an invention by August Brohl and Ludwig Leitz of an improvement to the bayonet mount, used subsequently for the M camera, wherein the invention is the addition of alignment indicators on the body and the lens. In other words, this is a patent on the red dots on the lens and body to help align the bayonet lugs. As disclosed, the bayonet mount itself was known and thus already in the public domain by 1951. [Austin] My 1949 Hasselblad has a red dot on the body, and a red dot on the lense, to aid in mounting alignment. Perhaps there is more to the patent than the red dots? - ---------------------