Patent: Canon Wide Angle Zoom for Full Frame Mirrorless Camera

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EOS 6D MK II
Apr 23, 2018
1,088
153
jolyonralph said:
ahsanford said:
[Adds "Is EF-M big enough to cover FF sensors" to the endless/unresolved debate queue, alongside the choice to use UV/clear filters or not.]
When the mount size and electrical contact positioning of the EF-M mount is almost *identical* to the Sony FE mount I can't see why we still have doubters. Well, I suppose in a world of Flat Earthers etc I shouldn't be that surprised. But the evidence is right there in front of your eyes. EF-M is full-frame capable. It was designed to be so, just as the Sony E/FE mount was.
Canon EF-M was definitely NOT designed to be FF-capable. There was an interview with a Canon exec who stated it. Can prob dig it out if really necessary. EF-M might possibly be "forced into FF service", just like the Sony E-mount. With all known downsides: lenses way longer, more complex, heavier and more expensive than need be = Sony FE. From how the chronology of events I am also quite certain that Sony did not design E-mount to be FF capable from the start. E-mount parameters are well chosen for APS-C but borderline for FF. Had Sony really wanted to also use it for FF, they would have made the throat width a few mm wider and things would have been much easier going forward.

Only due to the amount of discussion in the internets re. "the many mounts Sony has and how terribly confusing that is, OMG" and with all the angst by some vocal old A-mount farts, did Sony decide to NOT introduce a wisely chosen mirrorless FF mount (in addition to APS-C E mount). Poor results of that poor decision are evident.
 

jolyonralph

Kodak Brownie
Aug 25, 2015
1,094
310
50
London, UK
www.everyothershot.com
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Canon EF-M was definitely NOT designed to be FF-capable. There was an interview with a Canon exec who stated it. Can prob dig it out if really necessary. EF-M might possibly be "forced into FF service", just like the Sony E-mount. With all known downsides: lenses way longer, more complex, heavier and more expensive than need be = Sony FE. From how the chronology of events I am also quite certain that Sony did not design E-mount to be FF capable from the start. E-mount parameters are well chosen for APS-C but borderline for FF. Had Sony really wanted to also use it for FF, they would have made the throat width a few mm wider and things would have been much easier going forward.

Only due to the amount of discussion in the internets re. "the many mounts Sony has and how terribly confusing that is, OMG" and with all the angst by some vocal old A-mount farts, did Sony decide to NOT introduce a wisely chosen mirrorless FF mount (in addition to APS-C E mount). Poor results of that poor decision are evident.
I don't agree. If they had designed EF-M to be APS-C only then why waste valuable space making it bigger? It's not about being "forced into FF service", it's simply that both Sony and Canon were wise enough to plan ahead and make their mounts FF capable.

Why would the throat width need to be wider? What are these "poor results" you speak of? You do realise the throat width is the same as the Nikon F mount?

And oh yes, does that mean that you won't be able to use autofocus lenses faster than f/1.4? NO it doesn't. Because it turns out that having a smaller flange distance allows you to have a smaller throat width. And I can prove it. I have just put the EF 85mm f/1.2L on the Sony A7RII with a metabones adaptor. Autofocus is working fine, there's no clipping of the image, and vignetting is no different to how it is on the Canon.

Oh of course, we also get unclipped bokeh too, which is why I prefer this combination to any Canon DSLR for using the 85mm.

So. I hear a lot of internet experts proudly proclaiming there are so many problems with using the EF-M mount for full frame, or that the Sony FE mount somehow has problems with quality. But no-one has provided any real proof.


Let's talk about lens mount confusion.

Right now Canon has three mounts that are only partly compatible.

EF mount takes only EF lenses (plus a few special case TS, MP-E)
EF-S mount takes all of the above plus EF-S lenses.
EF-M takes only EF-M lenses (or others with an adaptor)

It doesn't take a genius to realise the EF-S mount is going to wither and die, Canon are surely aiming to replace the Rebel line with the EOS-M line. Their big push on the M50 is part of this. They'll produce cameras and lenses for as long as people want to buy them, but I doubt it has more than another five years in it.

It would be utterly stupid for them commercially to add a fourth mount type at the moment when it's not needed. The only viable options are to keep EF mount for the mirrorless (and then Canon has the problem that older lenses were not designed for mirrorless focusing and may not perform as well on this camera as they do on a DSLR), or to use EF-M (which ensures a new line of modern lenses that Canon can ensure are matched to the requirements and capabilities of the body).

And, unlike EF-S, the APS-C lenses will fit and work perfectly fine (albeit in crop mode) on the new camera. Some of them may even be useable almost to full-frame (I'd predict the EF-M 11-22 from about 15mm upwards could well do that) - which may not be of the same quality as a dedicated FF wide-angle, but would be handy for those who already own the lens.

And, of course, EF-M ff lenses will work fine on the crop cameras. Which would be great for the stalwarts like the inevitable 50mm f/1.8 or 85mm f/1.8.
 

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EOS 6D MK II
Apr 23, 2018
1,088
153
you don't have to guess or believe. The responsible Canon execs said it publicly in the interview i linked to. Unless you believe, they were not telling the truth.

Sony E-mount and Canon EF-M mount are very well chosen for APS-C. Sony mount was forced into FF service. Canon head designer for EF-M hints in the interview, that EF-M could possibly also be forced into FF servcie, but goes on to state that Canpon has no intention whatsoever and that it would be a very borderline ["crazy" in google translation of interview in Japanese :) ] and heavily compromised thing to do.

Already with EF mount Canon consciously chose a much wider throat width (open diameter) than what would be required "as minimum" for FF image circle. I think, they did just the same again for EF-M relative to APS-C image circle (1.6x crop). I have not seen a similar interview/answers from Sony execs, but BELIEVE, their E-Mount was designed for very compact APS-C cameras [NEX back then, later on A#### models] and was really put into "forced FF labor" as an afterthought and under marketing pressure/internet howling re. Sony introducing "all sorts of new lens mounts and abandoning good ole A-mount".

Based on these observations I also EXPECT/THINK/GUESS/BELIEVE/SPECULATE/CONJECTURE :) that Canon will bring a new FF mirrorless mount that will be very generously sized - relative to minimum for FF image circle and perfectly matched to the FFD they choose.

Mount and lens design is one thing Canon has repeatedly demonstrated that they really know how to get things "really right". :)