Sigma to announce 5 new lenses shortly, including a new 70-200mm f/2.8 OS Sport & 60-600mm f/4.5-6.3 OS Sport


CR Pro
Sep 17, 2010
Give me an R mount camera, I hook it up to one of the signal analyzers, and in ten minutes I will have a record of all the signals being exchanged between lens and body.... Then, you decode the signals... it is a very easy task with the right equipment, and it is almost inconceivable that Sigma, Tamron, and the others can not do this

I saw this go by awhile ago. It amazed me how simple the system really was.

I would be very surprised if Sigma/Tamron/etc cannot reverse engineer the codes. But, it is something I am watching. Even with the existing EF electronics, my general understanding is that they essentially mimic an existing lens. And there are still problems here and there. We will see if the problems get worse as Canon moved to RF mount.


Jul 20, 2017
everybody reverse engineered the EF mount. if canon would licence to anyone you'd have the following:
1) lens would be reported correctly in LR (doesn't happen always, only with some lenses)
2) peripheral illumination correction or whatever it's called would work
3) no issues with newly launched bodies

All this nothing about EOS/EF license.

“Due to international licences, it is not possible at the moment for companies outside Japan to offer AF lenses with EF or F mounts” – the same thing that the Zeiss team told me at the Photo Plus expo.


Dec 18, 2011
The Sigma 1.4 56mm sounds interesting for my M50 because I am in the need for a tele lens - from the front element this is a compact tele construction which will deliver stellar IQ because it is a downscaled 85mm lens which is in the sweet spot for lens designers (in this case downscaling is possible due to mirrorless design).

The only drawback: No flexible use is possible and maybe I will still wait for an EF f/1.4 50 IS lens (and after waiting several years I would be satisfied with a f/1.8 solution if it has stellar IQ wide open and is reasonably compact and costs ~400...450 $/EUR! The only chance to be used on EOS M & EOS R and maybe on EOS 5D is to use EF lenses ...

Hope dies last ...

EDIT: Read your post, noncho: not only the lenses are spot on, your post is too: I would just take a stellar EF-M f/4 10mm IS and a EF-M f/2.8 135 IS without too much hesitation. Seeing myself using the 10-22 usually at 10mm and I would accept f/4 if it is mostly free of ghosting, distortion, has very good contrast, good resolution and moderate CA


Jul 20, 2010
Springfield, IL
I will be interested in what improvements the 60-600 has over the current sports and contemporary lenses. After reading reviews that consistently indicated there was minimal difference in image quality between the sport and contemporary, I bought the contemporary for price and weight savings. Generally, I prefer the 100-400 with a 1.4 extender, but have certainly found the Sigma worth owning and under certain conditions preferable.

For me, the weight is a critical factor. I use both the 100-400 Canon and 150-600 Sigma with a monopod because at my age, hand holding gets difficult after awhile. Lugging heavier lenses around is not something I enjoy, especially at sporting events like track, where I have to race from one event to another. Point being, I would rate sharpness and focusing speed as most important, but weight can make a lens a non-starter for me if alternatives are available.
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