It looks like Canon is developing its own speedbooster for EF lenses on the EF-M mount.
Canon News uncovered a patent last week that showed Canon was looking at a new EOS M adapter, and again this week, a new patent showing the concept in more detail has emerged.
Japan Patent Application 2018-189864:
This patent application is for a converter that takes EF lenses and reduces the focal length and decreases the aperture all at once.
The example in this patent applications shows a 50mm f/1.4 lens (full frame) with a back focus of 39.80 (EF full frame) and converts the lens to a 40mm f/1.2 with an image height of 13.66 and an 18mm back focus, which would work for EOS M cameras.
If Canon is indeed going to keep the EOS M line around, developing a speedbooster for the system would be quite a nice addition to the lineup.
lol. you guys don't give up ... but .. Canon APS-C = EOS M. I don't see an "if" here.
I would likely buy an original Canon speedbooster for EF lenses on EF-M. :-)
Mathematically, say you have a 50 f/2 lens. If you were to shorten the focal length, optically through the adapter, you could have, say, a 25 mm f/1 lens. Why? An f/2 50 mm lens has a 25 mm aperture diameter (focal length/2). That same 25 mm aperture on a 25 mm focal length lens would become an f/1.
Now, I'm sure that a 2:1 lens adaptation would be kind of extreme, but something like a 1.25:1 or 1.4:1 shortening ratio would be less prone to problems.
Quirks and all. :)
well, in case you are not aware, "speedbooster adapters" exist as real products for a number of years already.
Only interesting question is, why neither Metabones nor Canon have not already launched an EF / EF-M speedbooster long ago.
And if Canon also charges €/$ 649 like Metabones, then I'll pass. My idea is €/$ 199 max. But Canon being Canon, they may well bring a white-paint EOS "L" speedbooster at 999 :p:D
well, the issue i see is Metabones pricing: 649 per click will for sure seriously curb demand. :-)
I started a thread about the Viltrox speed booster EF on EOS M. It's even less than €199 and the first impressions are not bad. Unfortunately, i didn't had the time to shoot some real photos but i will post some in a few days.
Now it is clear to me, why all of a sudden Canon/Metabones also want to get in on it. "Innovative" Canon always needs somebody else doing it first, before they also become "innovative" ... in due course ... :-)
Off topic, I really wish that Canon would drop the price of the EF-M adapter by about 2/3. It's just an extension tube and costs twice as much as the EF-RF basic adapter, which almost certainly includes electronics.
:) i love the idea of finding more light that a lens previously had possible.
Speed boosters have lenses in the optical path, so it is possible to deal with this situation.
Except that Canon originally filed the patent application back in 2017.