Originally posted by Rondec In a general sense, lens design is a known quantity and lens designs for a specific focal length probably look similar. That doesn't mean that there is any specific "borrowing" going on. Where there is rebadging going on, it is known. If a company actually "borrows" from another company, they will get a patent infringement lawsuit pretty quickly. Pentax can't just take, say a Zeiss Milvus design and backward engineer it and release their own version. In fact, when they are designing their own 50mm lens, they need to be careful that it doesn't look too much like existing 50mm lenses that are under patent protection or they will have to pay a licensing fee.
blabla... actually they did and they do.. there are contracts between those companies and those companies have agreements of consent and write contracts about what they will do and with which partner they will exchange technology, knowledge, etc.. conditions in such an agreement often include countertrades (or counter-deals if you wish so) or ... as you mentioned already ... license fees are paid.
For sure it is not very likely they would just take it.
And the backwards engineering, and modifiying to a certain point from where no patent takes effect is also possible ...
Talking about Zeiss, again: I am pretty sure Zeiss didn't dump the SMC recipe they got in exchange for taking lens design-knowledge over to PENTAX.
its now called "T*"...
There is one R&D relationship between Pentax an Zeiss, that is known to the public... that was in the 70ies.
(if they had something going on now or SIGMA has a relationship with "PENTAX-RICOH Imaging" who do you actually think, would tell you these days?)
Companies did exchange technology in the past and they do now.
And no most of the time you will not now, because companies don't want the consumers to know about "industrial arrangements".
And since most likely: neither you, me or any other forum addict on PF is actually named Ethan Hunt, Dark Dante, Astra or Kevin Mitnick... we will never know what is going on behind the curtains.
BUT KNOWING ALL THIS, THERE IS STILL ONE QUESTION LEFT: Who cares ? ? ?