Originally posted by Nicolas06 zoolander what you put here are hypothesis you craft in your own brain. It could be right, could be wrong. In the end it is of no importance anyway.
For something to be pattented come the constraint to actually publish the pattent and the ability for anybody to reuse the idea for themselve. That core to the idea of pattent as a way to not halt but promote innovation and sharing of ideas. But of course the pattent owner is bound to have the right to ask for some compensation in exchange.
As for factories, don't think that a factory can only produce a few things, always the same. The batch for lenses are very small anyway and once a batch has been produced you continue to pay the workers etc. What make sense is to have your factory doing as many things it can provided you can sell them.
Also don't think that everybody is going to do the same. Digitalis explained that many outsourced the lenses themselves but you can see a sigma factory video where they indeed buy the raw glass from a manufacturer but create the lens out of it themselves in factory.
So basically without an actual source to check what is really happening, we have no clue and a guess is just that a guess and is not more likely than any other option.
In the late 80's early 90's, Fiat, Volvo and Ford co-developed a 5 cylinder engine. At the same time Fiat, Saab and another (I forget) co-developed a car chassis - Saab 900, Alpha Romeo 164 etc etc.
Fords Fiesta uses engines manufactured by Peugeot. Mercedes uses engines manufactured by Renault and Nissan etc etc etc.
This is soooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo commonplace in manufacturing that its not funny.
I've been into cars for years, read 100's of auto magazines, and they speak of this all the time.
I am stunned, that all these photographers on here think that Pentax makes all their own lenses. I am stunned, that folks here think that Tokina and Pentax would duplicate manufacturing factories, for the manufacture of shared lens design.
I bet in years to come, that this new 24-70mm Tamron/Pentax lens, which is manufactured (in my brain) at Tamron, will somehow be magically manufactured at Pentax (in someone else's brain), You watch !
I've got the 10-17 fisheye, 12-24, 16-50, 50-135, and I believe that they were almost certainly made at Tokina, under the watchful eye of Pentax, and to the stringent specification of Pentax. I don't mind that, they're fantastic lenses. Perhaps they WERE'NT made at Tokina, but common sense shows that Pentax and Tokina had a joint venture, and to save manufacturing costs they would manufacture them at one plant.
Here's the example of the 18-270. Folks believe the Pentax version is made by Tamron, and it would be safe to assume that Tamron manufactures this lens for Pentax. Now take a look at how they test:
Pentax version
https://www.ephotozine.com/article/pentax-smc-da-18-270mm-f-3-5-6-3-sdm-lens-review-21305
Tamron version
https://www.ephotozine.com/article/tamron-af-18-270mm-f-3-5-6-3-di-ii-vc-pzd...s-review-15448
Both with a different outcome. Someone might suggest that perhaps Pentax pays a licence fee to Tamron to make the lens and manufactures the lens at Pentax. But common sense dictates that a company will not duplicate an entire factory line - its cheaper to make them at one plant.