[D1N0]

24-70 F2.8 I presume.

[kenspo]

24-70 F2.8 I presume.

Yes

[Rorschach]

That's great news !!! I guess the 24-70mm f/2.8 from sigma (Macro or HSM version) was the only alternative in K mount for this range and aperture, even if Sigma seems to boycott the K mount nowadays (no 150-600mm and no 24mm f/1.4 Art....)

That's all right..I have boycotted Sigma ever since realizing that they are backward engineering their stuff and not paying royalties to the rightful companies. I sold the only Sigma product I had, a 1.4 TC and have never looked back. Screw them.

[ChristianRock]

That's all right..I have boycotted Sigma ever since realizing that they are backward engineering their stuff and not paying royalties to the rightful companies. I sold the only Sigma product I had, a 1.4 TC and have never looked back. Screw them.

What lenses are they backward engineering?

I mean, how is that different from all the double gauss lenses out there? Isn't everybody copying Zeiss with their primes? And didn't Angenieux invent the retrofocus wide angle lens in 1950, and isn't every SLR wide angle lens now derived from that concept?

Or am I understanding it incorrectly and is Sigma actually infringing copyrighted designs?

[Kunzite]

They're reverse engineering the mount protocols, not the optical designs (and apparently that's legal)

[normhead]

What lenses are they backward engineering?

I mean, how is that different from all the double gauss lenses out there? Isn't everybody copying Zeiss with their primes? And didn't Angenieux invent the retrofocus wide angle lens in 1950, and isn't every SLR wide angle lens now derived from that concept?

Or am I understanding it incorrectly and is Sigma actually infringing copyrighted designs?

The difference is, licensing pays for the mount and new development, backwards engineering pays your own engineering department, but not the creator of the mount. Reverse engineering is a way of avoiding copyright infringement. And in theory saving money by not contributing to the the developers of the mount.

Whether or not Sigma does this I don't know, but I suspect they do on everything. Why.. white dots aligning with red dots when mounting a lens, theres no reason to do this, except to avoid copyright restrictions. I have no idea how far this goes in the lens design etc.

[Rorschach]

They're reverse engineering the mount protocols, not the optical designs (and apparently that's legal)

I am not claiming that it is illegal it is just something that I will not support.

It is part of a larger thing actually: every time you buy something, you essentially cast a vote, support some approach, agenda, philosophy, business ethic etc.

I guess this sort of thinking comes naturally if one makes the active choice of trying to live supporting sustainability...we buy our house electricity from wind power companies even though it is more expensive than regular electricity, buy local and organic food items always when possible and so on...

[Stavri]

I am not claiming that it is illegal it is just something that I will not support.

It is part of a larger thing actually: every time you buy something, you essentially cast a vote, support some approach, agenda, philosophy, business ethic etc.

I guess this sort of thinking comes naturally if one makes the active choice of trying to live supporting sustainability...we buy our house electricity from wind power companies even though it is more expensive than regular electricity, buy local and organic food items always when possible and so on...

+1, Well said...

[Rorschach]

What lenses are they backward engineering?

I mean, how is that different from all the double gauss lenses out there? Isn't everybody copying Zeiss with their primes? And didn't Angenieux invent the retrofocus wide angle lens in 1950, and isn't every SLR wide angle lens now derived from that concept?

Or am I understanding it incorrectly and is Sigma actually infringing copyrighted designs?

I guess you got your answer in the messages above. Henri Cartier-Bresson is a favorite of mine too, by the way :-)

[Kunzite]

I am not claiming that it is illegal it is just something that I will not support.

I understood this, and IMO it's perfectly reasonable - you get the right to decide how to spend your money.
My comment was related to Christian Rock's "infringing copyrighted designs" - which if true would get a company sued. Perhaps "illegal" was not the best word.

[JimmyDranox]

Every patent has an expire date. I don't know exactly, but if I remember well, was 20 years. So, I don't wonder that Sigma or Tamron don't pay licence fees for a mount that's older than this..

[D1N0]

The mount is 40 years old but the AF protocol can be updated with every camera.

[ChristianRock]

Every patent has an expire date. I don't know exactly, but if I remember well, was 20 years. So, I don't wonder that Sigma or Tamron don't pay licence fees for a mount that's older than this..

This might also explain why Canon especially, makes changes to the mount to stop older 3rd party lenses from working in their newer cameras...

And I'd have to read more about this issue of "supporting the mount" to see if it's something worthy of being concerned about. As far as I know, just the fact that they make lenses in a certain mount, is a form of support of that mount and that system, and might get people to buy cameras from the original manufacturer. But what do I know... I haven't researched this issue enough.

[Rondec]

This might also explain why Canon especially, makes changes to the mount to stop older 3rd party lenses from working in their newer cameras...

And I'd have to read more about this issue of "supporting the mount" to see if it's something worthy of being concerned about. As far as I know, just the fact that they make lenses in a certain mount, is a form of support of that mount and that system, and might get people to buy cameras from the original manufacturer. But what do I know... I haven't researched this issue enough.

I think it is a difference between Tamron and Sigma. Tamron actually pays a licensing fee to make certain that their lenses will work on a given mount, while Sigma just does their best to reverse engineer things. Sigma lenses still usually work decently, but not always.

[Winder]

I understood this, and IMO it's perfectly reasonable - you get the right to decide how to spend your money.
My comment was related to Christian Rock's "infringing copyrighted designs" - which if true would get a company sued. Perhaps "illegal" was not the best word.

The reason there are 60+ different K-mount branded lenses is because there was no patent on it and like screw drive, SDM is a dumb technology which simply moves the AF elements forward or backwards. Might be as simple as reversing polarity. SDM uses the old Power Zoom contacts to power the AF motor. It was't designed from the ground up to have an in-lens AF motor like Canon. All the companies that evolved from screw drive had very simple AF systems and that maybe why they trailed Canon. Sigma didn't have near the trouble with the other mounts who evolved from screw drive (Nikon, Pentax, Sony) as they did with Canon or Olympus 4/3.

I guess this sort of thinking comes naturally if one makes the active choice of trying to live supporting sustainability...we buy our house electricity from wind power companies even though it is more expensive than regular electricity, buy local and organic food items always when possible and so on...

Does the company you buy power from pay a royalty to General Electric since GE was formed by Bush Electric (and others) and Bush Electric invented the wind turbine. There are no telling how many technologies that Ricoh/Pentax use that were designed by other companies. Everyone building a Sonnar, Planar, or Distagon lens is copying work done by Zeiss to some degree or another. Hoya/Pentax would be one of the companies that settled with Kodak over not paying to license technology that Kodak patented..... Along with everyone one else in the industry. There is no camera brand you can use that isn't reverse engineering technology. Even PDAF technology itself was reverse engineered by Japanese camera companies. Honeywell sued a dozen different camera makers over the AF technology with Minolta shelling out $120 million dollars and ultimately going under.

---------- Post added 04-14-15 at 02:48 PM ----------

I think it is a difference between Tamron and Sigma. Tamron actually pays a licensing fee to make certain that their lenses will work on a given mount, while Sigma just does their best to reverse engineer things. Sigma lenses still usually work decently, but not always.

Do you have a link on Tamron licensing AF technology from different manufacturers? Sony owns a large chunk of Tamron, so I'm sure there is a lot of sharing, but what about other brands?