Patents, I would have thought.
Hi
Sort of but only part of story, Cosina are frequently a 2nd tier company, because they can do short runs for less cost that the 1st tier companies, and both Cosina and 1st tier company make more profit thereby. To do this both companies sign a detailed contract with loads of 'weasel' words, like not reproducing the design in any recognizable form for ten years etc. The wont be able to clone a RD/1 for their contract with Epson, they may not be able to do a digital M mount rfdr camera either.
The probable reason Zeiss selected Cosina is that the Japanese camera industry has pooled all its patents, so that any Ja company can use any Ja patent freely. So the Cosina 'ikon' is really a Ja ikon and Zeiss get a cheaper camera then they could have made themselves cause Cosina are good and both all the Zeiss and Ja patents are/were free. If Cosina were contractually free to make a clone they would need to pay Zeiss for the Zeiss patents, the resulting package wold have Cosinas 1st tier mark up and the Zeiss patent premium, probable only a little dearer then a Bessa M (say x1.2-1.5).
It is interesting to look forward to what Cosina will do next, all their kit is guite reasonable for the price, but second guessing is petty impossible without a detailed knowledge of the 'weasel' word constraints.
Cosina bought rights to use the Voightlander name to allow 1st tier sales, all my CV lenses have been are excellent performers, I sold 2x Lux 3x Elmarits, and a Super Angulon, cause there was not a detectable difference, apart from glow (sic flare) from a lux. I'm sure I'm going to be told that is just wrong, but my Leica lenses are just history, I had them all from new as well... my CV are beaten up used shooters...
Noel