Tamron/Tokina/Sigma reverse engineering??

[stringphysics]

Obligatory Justification:

This must have been discussed in some thread somewhere but after ten minutes of searching I didn't find anything useful so here goes:

I have noticed (or maybe there are just a lot more customers) that Sigma gets a huge number of complaints on the forums regarding incompatibility with new bodies (and rechipping) versus Tamron or Tokina. I have read (somewhere) on more than one occassion that Tamron and Tokina license the EOS/EF mount from Canon while Sigma reverse engineers it and therefore runs into troubles down the road and so needs rechipping. I almost never hear anything about Tamron/Tokina problems along those lines. Is this "licensing" a myth or is it true? I ask because all three companies make some great glass and I'd like to avoid building a system around lenses that might stop working after I upgrade my body in the future. Can someone point to a credible resource (such as an official announcement from the manufacturers) that can shed light on all this? Thanks.

 

[p5freak]

Canon has never licensed the EF protocol to anyone. Chuck Westfall from Canon USA said that himself in the RobGalbraith forum. The link i have doesnt work anymore, so you have to login there, and search for it.
Tamron and Tokina simply did a better job of reverse engineering than Sigma.

--
Stupid is as stupid does - Forrest Gump

 

[hbx2004]

I'm sorry, I don't recall where I've read, but less than year ago, it was a interview with one of the Canon's high representative...

On direct question about (rumours) licensing lenses, he answered, that Canon doesn't license lenses to ANY manufacturer.

Btw. you can be sure that, if some manufacturer would have licence, they would make a big hype out of it. After all, that would guarantee, that lenses are not only within specs, but are also future compatible.

Greetings,
Bogdan
--
My pictures are my memories
http://freeweb.siol.net/hrastni3/

 

[stringphysics]

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