I just saw a Zeitmayer brass lens with an interesting sort of globe shaped front element. Can anybody tell me what it is and what its supposed to do? Thanks!
The only optical firm I can think of that comes close to this name is LEITMEYER, Munich, which was mainly known for their Sytar ( double anastigmat) lenses.
If you are referring to the one on ebay its missing some elements. There should be 2 additional elements to use the lens as a convertible. The lens is highly saught after by collectors of American made optics.