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Will Canon allow EF lenses to work on future RF bodies?

Started 1 month ago | Discussions thread
Sittatunga Veteran Member • Posts: 5,406
Re: There's no evidence that Canon will do anything differently

EmotionBlur wrote:

RDKirk wrote:

EmotionBlur wrote:

That's always been the case, but this time it's a matter of not infringing Canon's AF patent. Samyang had to pull its reverse-engineered AF lenses off the market because of that and now it's got manual focus lenses only.

It's always been a case of not infringing on Canon's patents. Canon has never been indulging infringements on its IPs. If Samyang pulled its lenses, it's because Samyang knew they were infringing on Canon's IPs.

So, how did Sigma and Tamron manage to do what they did with EF mount? Is there a chance of buying licenses, or did the EF mount patents expire before they could do anything? (I hope for the first).

Reverse engineering. Certainly Sigma, in the 80s and 90s, prided themselves on their reverse engineering and made a big thing about never applying for licences (not that Canon were likely to sell or grant them then).  This is probably why film era Sigma lenses generally don't work properly on DSLRs.

Japanese and US patents expire after 20 years. 2007 was 20 years after 1987, and Sigma were still having trouble making completely compatible EF mount lenses ten years after that.  (Their infamous concentric circles at full aperture.)

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