Patent: EF/EF-S Adaptor For Canon Full Frame Mirrorless

[Khufu]

I enjoy looking at these diagrammes regardless of accompanying text/interpretations and seeing what comes to me

When I look at this, whether correct or way off I'm inclined to conclude I'm looking at:

1) A MIRROR, right? That trapezoid block in the middle, with the hinge looking bits at the top? Maybe?

2) M4/3 and APS-C MASKS with MOTOR: far right, for motor. One mask in light path, other to the right towards motor. Relative to apparent "mirror" size these appear to be approx M4/3 and APS-C, if not APS-C and APS-H, though relative sizing implies the former to me.

Keith et al; yeah, I was thinking we're in "Mirrorless Focal Multiplying" territory, hey, that's a teleconverter!... alas, the prototype you've acquired may require space-sharing by lens and adapter elements and photon teleportation to hit everything in the right order ...your conclusion seems fairly sound though, re: teleconverting EF-S!

I'm inclined to believe Canon are covering bases before third parties attempt the same thing - this all seems like unlikely to make it to market (more lens elements to diffuse little light sparingly? Meh) but we could spend days debating potential uses...

Okay, having said all that, I'm going to actually read some of the patent info now, then I'll be back to apologise for my earlier, silly assumptions once I know what's really going on here

rrcphoto: thank you for the link, much appreciated! Do you keep on top of these things, generally know where you're looking to find patent info etc? Just curious - I don't know if it's easily done or not but thanks!

Neuro: Aye, unfortunately for interested minorities it's often the case that the big players aren't too interested in mildly-profitable yet exciting endeavours... and it's fair to say they'll shy away from will:won't it bets, like shipping M2 and M3s globally - but maaaybe Japan & (East?) Asia's enthusiasm towards the M and A7 series (serieses? English brainfail from Englishman..) can be enough to prompt at least an importable FF Eos M, daft EF-S adapters and all

 

[Khufu]

...and I'm back, fork and alls, to eat my words

Okay, so it's an elaborate EF & EF-S to FF adapter, with no optical/focal multiplying elements, incorporating a mask when EF-S lenses are attached; I can only imagine this is to preserve intended representation of the EF-S lenses' capabilities, without Canon being accused of making EF-S lenses with rubbish Full Frame qualities!

What I thought was maybe a mirror may simply be a door/cap, entirely covering the sensor during lens changes - either that, there's a third mask ooor there's only one mechanical mask which moves over to the shown STM to be adjusted or closed.

I don't love this excessive bit of hypothetical kit - if it's the only model Canon offer the simplistic third party sales should be healthy!

 

[BRunner]

It looks too big for use with consumer mirrorless FF camera... Maybe for coming FF EOS Cinema camera? FF C500 mark II?

 

[stefang]

It looks like the diagram displays a lens too.
Wouldn't it make sense that the adapter simply tells the camera whether a EF or EF-S lens is attached, forcing the camera into crop-mode in case of an EF-S lens?

 

[e17paul]

In general, what would be the approximate time frame for something like this to come to market?

Just curious.

I'm sure that it could be immediate if Canon wanted, but will surely wait until the full frame Eos M comes along. That will only be when EVF technology has improved to Canon's satisfaction, and they have successfully developed it for their cameras. Electronic technology changes fast, but Im expecting Canon to take a little longer.

The Eos M mount is larger than the (full frame) Leica M and Sony FE mounts, so therefore allows for future full frame mirrorless cameras.

 

[9VIII]

Yeah... I haven't really seen any lenses exploit the fact that APS-C sensors are smaller and they could make the lenses faster by a stop.

For example... instead of the full frame 50mm F1.8 STM, they could make a APS-C 50mm F1.2 STM (one stop faster) - for the same $125 price - this is key!
40mm F2.8 full frame pancake? make it a F2.0 for APS-C for the same price.
Same thing goes for various other lenses.

However, it seems that Sigma have finally brought something to the table with the:
Sigma 18-35mm f/1.8 DC HSM Art Lens for Canon... a fixed F1.8 through the whole focal length.
However, at $800 it is wildly expensive.

Unfortunately it's not quite that simple. Remember you're adding a focal length reducer, so to get your 50mmf1.2 you would have to start with an 80mm lens, it's going to be big to begin with but then you're also adding complexity to the formula. Look at the Zeiss Otis line for an example of the size of an unusually complex lens. I have no idea if a focal length reducer could be incorporated into the formula without adding elements. If it can, great, if not, you're adding another few hundred grams to an already large lens. The Canon 50mmf1.2 is 590 grams and the 85mmf1.8 is 425 grams, so you're probably pushing that above the weight of the 50f1.2 just to accomplish the same level of light gathering with a smaller sensor.
But remember the added complexity of the speed booster is probably going to reduce image quality, and that compounded by the reduced IQ from using a smaller sensor.
Which is not to say that it shouldn't be done, but it sounds like a challenge and there are big trade offs.

I get the impression that this sort of idea hasn't been tried before just because no-one thought that people would put up with having a 2lb 50mm lens before the Otis was announced. Zeiss actually used a retrofocusing design for a lens that's longer than the flange distance (retrofocus an optical trick that moves the focal plane and allows lenses to use a focal length shorter than the flange distance, on an SLR that's everything below 40mm [note that retrofocus has nothing to do with focal length reduction we're talking about]). The Otis design is totally redundant, but they managed to use the extra elements to their advantage. I'm assuming this sort of thing wouldn't be possible without computers.
The question for Canon would be something like "will crop shooters pay $1,500 or more for a 50mm lens?" But looking at what Sigma is doing, I have to wonder if they couldn't make something happen for under a grand.
I know I would pay $1,000 for a 2lb 50mmf1.2 equivalent crop sensor lens, but how many other people would is a good question.

Thus far companies like Fuji have opted to use larger normal apertures for their lenses, e.g. the 56mmf1.2.
The reason you don't see f1.0 lenses is that the circuitry on current sensors doesn't allow light gathering past a certain angle, so f1.0 is useless on digital bodies (http://www.dxomark.com/Reviews/F-stop-blues)
Fortunately we're on the brink of introducing Back Side Illumination, moving the circuitry to the other side of the sensor, which has the potential to improve things drastically.
(Yes, right now a large percentage of the sensor you look at when you take your lens off is circuitry and not light gathering pixels.)

 

[DRR]

My theory, which I have floated around here multiple times -

EF-M is Canon's mount of the future for APS-C. Eventually all consumer level APS-C (rebels included) will go EF-M mount. There will be a "large" variant (Rebel Mirrorless) and a "compact" variant (current EOS-M). There will no longer be mirror box consumer cameras. There is already an existing EF/EF-S adapter for EF-M.

New FF Mirrorless mount in the future (EF-X for argument's sake). FF will eventually move to the new mount but with 100million EF lenses out there, Canon knows they need an adapter. So as native EF-X lenses are introduced, existing users are "kept in the Canon family" with a EF/EFS to EF-X adapter. This adapter basically adds the space back in, that Canon has taken out, by removing the mirror box. Of course EF-S lenses will produce an image circle that won't cover the whole sensor but that problem is pretty academic, and one that Nikon has already solved - in camera crop mode.

 

[pedroesteban]

Since many people here don't have a background in technical drawings, let me help:

- The "100" label shows the mirrorless camera
- The "102" label shows the adaptor
- The "101" label shows a lens mounted on the adaptor

As someone pointed out before, the adaptor comes with a housing for the EF/EF-S converter / mask. However, the adaptor length is about the same as the camera length.

Looks like a Canon FF mirrorles is coming. It wouldn't surprise me if Canon developed a satisfactory EVF and decided that the upcoming 1dx mk II, 5d mkIV or 6d mk II will be mirrorless. I'd bet on a mirrorless 6d mk II.

 

[mb66energy]

(1) It looks like the diagram displays a lens too.

(2) Wouldn't it make sense that the adapter simply tells the camera whether a EF or EF-S lens is attached, forcing the camera into crop-mode in case of an EF-S lens?

Ad (2): It would be easier to read the data stored in the lens which identifies the lens - if EF-S is part of it's name the camera knows it is an EF-S lens. So no adapter needed for this.

like pedroesteban written while I worte my post:
Ad (1): I quess you are right. I think the curly brackets on the left designate the body (100), the lens (101) and the adaptor itself (102). This explains the complex arrangement of lens groups with ~15 lenses which are supported by a complex mechanics.
The adaptor itself has two functions: To increase the flange distance between mirrorless body and EF/EF-S lens AND provides the option to choose between two diaphragms to cut out flare/vagbounding light depending on the image circle the lens has.
ADD: The lens might be the EF-S 55-250 mark i version - see the lens arrangement drawing under
http://cweb.canon.jp/ef/lineup/ef-s/ef-s55-250-f4-56is-stm/spec.html

So: no speed booster or anything like that. Just a clumsy device that helps to reduce non-wanted light of EF-S lenses on a FF sensor. I would solve the problem by a "baffle diaphragm" consisting of several blades which were adjusted to EF and EF-S lenses to keep the thing compact.

 

[Andyx01]

Yeah... I haven't really seen any lenses exploit the fact that APS-C sensors are smaller and they could make the lenses faster by a stop.

For example... instead of the full frame 50mm F1.8 STM, they could make a APS-C 50mm F1.2 STM (one stop faster) - for the same $125 price - this is key!
40mm F2.8 full frame pancake? make it a F2.0 for APS-C for the same price.
Same thing goes for various other lenses.

However, it seems that Sigma have finally brought something to the table with the:
Sigma 18-35mm f/1.8 DC HSM Art Lens for Canon... a fixed F1.8 through the whole focal length.
However, at $800 it is wildly expensive.

When you compress an EF image circle to an EF-S size, you also effectively reduce the Focal length.
e.g. a 50mm 1.8 with a 0.625X TC would result in: 31mm f/1.1

An 85 f/1.8 on the other hand would be closer to what you are after: 53mm f/1.1

As far as adapting EF-S lenses to FF sensors, a 1.4TC is just 0.2x shy of doing just that - (however there is the obvious compatability issue with the shape of the mount.)

18-35 f/1.8 isn't really all that expensive considering:

24-70 f/2.8 ----0.625 TC'd---> 15-46 f/1.8

15-46 f/1.8 = $2000
18-35 f/1.8 = $800

That said, I don't beleive this "EF/EF-S Adaptor" is a converter, I think it's an "Adapter" just like it reads.

 

[Famateur]

Adapting crop lenses to a full frame sensor doesn't make any sense.

I don't pretend to have any clue what Canon is planning, but I often hear people that are heavily invested in EF-S lenses and are ready to try full frame say, "I've got to sell all my lenses anyway, so I might as well consider switching systems." Having an adapter that would allow them to keep using their EF-S lenses might convince them to stay with Canon. That would make sense (at least to those who didn't plan ahead and buy EF lenses for their crop body).

As for full frame mirrorless from Canon, I think it's inevitable (if the competition continues to apply pressure) -- I just don't think it will be any time soon. At least several more years, in my opinion...

 

[Famateur]

...Asia's enthusiasm towards the M and A7 series (serieses? English brainfail from Englishman...

How Gollum would say it.

 

[dak723]

I think folks are way over-complicating things. Nor does it imply any new camera is immanent. I think it is very simply a patent that will let Canon make an adapter IF they ever decide to make a FF mirrorless camera. The adapter will allow folks to use their current EF lenses on the mirrorless camera at full frame and their EF-S lenses at the usual crop size. The camera as well as the adapter will be able to switch from one size to the other. No changes to the focal distance or anything else.

 

[Mt Spokane Photography]

. It wouldn't surprise me if Canon developed a satisfactory EVF and decided that the upcoming 1dx mk II, 5d mkIV or 6d mk II will be mirrorless. I'd bet on a mirrorless 6d mk II.

Canon buys EVF's from Sony, their rear LCD's come from Sony as well, at least the one's I've removed say Sony on them. Canon does Not develop or make EVF's.

although companies in Japan are competitors, they are also business partners and buy pieces and parts from each other. Its a lot different than what we have in Western Companies.

As for a lens mount, perhaps some remember the new lens mount for FF that was in the patent news a few months ago. Canon has already said that the "M" mount is not suitable for FF.

 

[optikus]

Hello,

what I expect to be seen in the near future is a new type of FF-mirrorless camera from Canon, and the patent shown here is for me a fitting element of this to grant continuity with the EF and EF-S-Lineup. Sony has shown that it can make sense to have a crop-mode in combination with high-megapixel-sensors, 5Ds has too. Therefore the compatibility of a VF-mirrorless perhaps as a competitor for A7II necessarily has to handle also APS-C-lenses if Canon will avoid an affront to the APS-C-Users they have. The patent shown seems to contain what Sony-Users know well, adaptor to other company-used standards. A E/EOS-Adapter from Sony is hard to imagine, a cooperation to manufacturers of those adapters is possible, as heard the A7II shall work together with EF-lenses nearly or identical as good as a EOS-body ... It's the proof for me that it is possible when it shall pe possible!

 

[Mt Spokane Photography]

...
As for a lens mount, perhaps some remember the new lens mount for FF that was in the patent news a few months ago. Canon has already said that the "M" mount is not suitable for FF.

In a thread somewhere else, commentators were remarking that Canon's EOS was better because Canon hadn't changed mounts very often. This will be Canon's 6th lens mount and it will mean more lens mounts than any other manufacturer (unless I'm mistaken.)

I suppose you are counting mounts for camcorders too

For Canon SLR/DSLR's, I am aware of three mounts. All Canon SLR bodies had one of the three mounts, DSLR bodies have had only one mount. (Lenses have EF and EF-s, but all the bodies have a EF mount)

Canon started with a version of a Leica R mount for their first DSLR. They then went to the successful FL / FD breach lock mount, and then the EF (Electric Focus) mount which is used on all DSLR's since.

The EOS M is not a DSLR, but has its own mount. EF-s lenses mount to a EF mount but not on FF DSLR's. You can buy some Canon cinema cameras with the cinema industry standard PL mount, but its not a Canon mount.

I can still use the first EF lens made on any current canon DSLR. I believe that only Canon is able to use their first autofocus lens mount with complete compatibility on current models. Nikon can't., Sony/Minolta can't. The reason is that the other camera makers used a screw drive before going to a electronic focus system, so they had to redo their lens mounts to add more contacts. I think you will find multiple versions of their mounts.

I can't begin to count the dozen or so versions of mounts that Pentax used.

Now, with the many mirrorless cameras in circulation, its getting pretty crazy. Buyers run the risk of having lenses that only fit discontinued cameras. This is a reality, because, some manufacturers and or models will drop out.

 

[johnctharp]

I think that the only reason for this patent to exist is that the current EF -> EF-M adapter 'crops' EF lenses to an APS-C image circle.

The EF-M mount, same as Sony's E-mount, has room for a full-frame sensor, and with the proper adapter would allow full usage of EF lenses.