Opinion: Canon is causing its own problems with the RF mount

[Dradis]

"It is impossible for this mount to be adapted to the new RF full frame mount"
Why would you want a EF-M lens that only fills up an APS-C area on a full frame mount? EF-S also can't be used on EF and nobody batted an eye yet.
The new mount tho, lets you use EF, EF-S and probably also FD soon.

I think the issue here is that if canon ever makes an APS sensor ILC with an RF mount, older EF-M lenses will not be usable. Unlike current EF users, if this happens EF-M users would not be able to keep using their lenses.

I see 3 possibilities, none of which are good for EF-M users.
1) canon keeps using EF-M for APS cameras. EF-M users will no longer have the choice of using new full frame lenses (once EF fades out)
2) canon ditches EF-M in favor of RF. EF-M users can’t bring their old lenses to the new cameras.
3) canon makes a new “RF-S” to replace EF-M similar to EF-S. Same down sides as 2.

I think the EOS-M line was a kind of experimental attempt at mirrorless. I think the R line will stick and and it’s just too bad for M users.

 

[Josh Leavitt]

Respectfully, perhaps you should consider the difference in aspect ratio in calculation, too. If I'm right, Canon APS-C sensor is 22.2(w)x14.8(h) mm and Super 35 is 24.6(w)x13.8(h) mm, that is, Super 35 sensor is a bit larger in width. Therefore APS-C image circle may not fully cover the Super 35 sensor, unless M lenses are built with larger image circle, which is quite likely. However, lens makers don't publish the image circle info so we won't be sure about that. Since Super 35mm is slightly larger than APS-C, in principle, using an APS-C lens while shooting in Super 35mm mode does not seem to be practical, without further tweaks.

I would imagine the wider focal lengths of current EF-M lenses would struggle. The EF-M 11-22mm for example, suffers up to -3 stops of light in the corners wide open at 11mm. Normal and short/mid telephoto lenses don't seem prone to the same amount of vignetting, so it's possible that most of the EF-M glass would perform well enough. Although Canon would almost certainly create a higher quality line of lenses for an EF-M super35 video platform if they pursued that route, since a dedicated video camera would likely be much higher-end in terms of electronic components than standard EOS M stills cameras (hence demanding more proprietary lenses for video work). Probably similar to what they did with the tilt-shift lenses for the EF line; only EF-M video lenses wouldn't just have a larger image circle, they would also likely include a t-stop ring as well as a separate textured focus ring.

 

[traveller]

Well, I dont own EF-M lenses and noone can be bought in EF-M by an amount that it would really matter to him financially. If you had every EF-M lens that there is (all for crop and you knew that when you bought them), then you lived with the knowledge you would have to buy full frame lenses.
You cant use EF-S on FF DSLRs. You can‘t use EF-M on FF MILCs. Ok.
So crop will be an opportunity for EF-M, or it is just a mount for the more consumer end of MILCs that Canon offers...

Whilst there is truth in what you are saying, the point of having full frame lenses that mount onto APS-C bodies is to capture and lock in future full frame users before they have even purchased their first full frame body. If the user knows they need to sell all their lenses (and that their current APS-C body is of no further use), they are much more free to consider competitors systems. Perhaps that is good for Canon EOS-R system users, as Canon will have to make damned sure that they win any future spec sheet war!

 

[Tangent]

Canon ef-s body can use EF lenses without an adapter
Canon ef-m body can use EF and EF-S lenses with a Canon adapter
Canon RF body can use EF and EF-s lenses with a Canon adapter

That looks like pretty good compatibility to me.

ef-m lenses can not be used on RF. Well, ef-s lenses can not be used on EF FF. I don't think getting crop lenses to work (in some sort of crop mode) on FF bodies has ever been a priority for Canon. The RF body will take ef-s lenses via an the adapter because there is room for it, so why not toss in compatibility? For my needs, using a crop lens on a FF body is something I would not want to do much anyway.

It has been a trend to slow down on ef-s lens introductions for a long time already. Long lenses will continue to be EF lenses for the indefinite future, as evidenced by the new BWL's. No EF lens -- or EF-s lens, for that matter -- will ever be orphaned -- they will work with all future ef-m and RF bodies (via adapters). Again, pretty good compatibility.

The problem in the midrange is that ef-m lenses so far are designed to be small as possible. What we need for an enthusiast M body is something like a 15-70 f4 ef-m lens of high optical quality. The 15-70 f4 ef-m quasi-L would be big for an ef_m lens, but still more compact than a 24-105 EF or RF lens: just the thing to kit with a future M5mk II or M7 (a mirrorless 7d series). ...Actually, that 15-70 f4 IS quasi-L EF-M lens sounds pretty darn good! Canon, please steal my idea! (And DON'T go 3.5-5.6 on us). This is one EF-M lens that should be designed for performance first, compactness as a secondary consideration. (To go small just use the existing EF-M 15-45 3.5-6.3 IS.)

Only Canon knows what future dslr bodies they will make. I suppose they will make more dslr bodies as long as demand is sufficient. But the end game is to wind up with new ef-m bodies and new RF bodies only. Maybe a decade or more from now the last new dslr will be announced, and it will be a poignant day, as it was when film bodies died. New EF lenses will probably be made for an even longer time, because if the shorter throw of the RF format is not needed it still makes sense to make lenses that can be used by both ef-m and RF camera bodies, as well as the EF and EF-S legacy cameras which will still be out there.

I think all the hand-wringing on this issue is a little bit too melodramatic, but ymmv.

 

[neuroanatomist]

As an example, Nikon terminated the "Nikon 1" just before the Z System went on sale. Canon's M system has been arguably more successful...

Nikon may have 'officially' discontinued the 1 series in July, but the last camera in the series came out in 2015.

As for the EOS M being 'arguably more successful', the Nikon one was a commercial flop, the EOS M line is the best-selling MILC line globally. To claim the EOS M is 'arguably more successful' is disingenuous at best, but arguably just an asinine statement.

 

[traveller]

Nikon may have 'officially' discontinued the 1 series in July, but the last camera in the series came out in 2015.

As for the EOS M being 'arguably more successful', the Nikon one was a commercial flop, the EOS M line is the best-selling MILC line globally. To claim the EOS M is 'arguably more successful' is disingenuous at best, but arguably just an asinine statement.

But the irony is that Nikon 1 being a flop has given Nikon the opportunity to start with a clean sheet and a better mount without alienating a large slice of their user base. Whether they follow through on this is a different matter.

 

[efmshark]

The short answer is that if the EF-M mount was capable of using RF lenses with an adaptor then there would have been precisely zero benefit in using the RF mount over using FF EF-M mount to begin with. Ie it may be possible assuming you're a genius with enginering to physically adapt the lenses assuming the rear elements fit, but it'd vignette like crazy.

Despite the claims in the original article, EF-M mount is capable of using RF lenses with an adaptor. Even though the flange distance difference is only 2mm, a significant part of the adapter can go inside the EF-M camera and around the RF lens, so it is possible the design some kind of an adaptor. This adaptor would only need pass through electrical signals, and the pins being at different radial distance may actually help the wiring.

Of course, there is always possibility for adaptors with built in optics. In this particular case, a speed booster adaptor that would keep the original angle of view of the RF lens but provide a 1 f-stop boost would be particularly interesting.

However, such an adapter would only be useful for supporting a APS-C size sensor.

The reason Canon designed the RF mount is to support a full frame sensor.

 

[riker]

Two thoughts.
1) Maybe on the long run EF-M will be for APS-C and RF for full frame and that's it. And the whole world will be MILC, DSLR is the past.

2) I see a whole lot bigger, forgotten debate behind this current situation. The whole question of the APS-C industry and how Canon never got serious about it. I have used EF lenses on APS-C bodies for almost a decade (2001-2009) until I bought 5Dmk2, simply because L lenses only existed with EF mount. It meant carrying the extra weight and size of a full frame lens even though the sensor only used a portion of it. Lots of back pain, airport problems, sweating on Africa's dirty roads and whatever.
Problem still not solved after almost 20 years. Even though we have 7Dmk2 which is kind of a serious camera, we still don't have appropriate EF-S lenses. If you have an EF-S or EF-M body, most likely you will end up using some EF L lenses instead of having their EF-S or EF-M counterparts which would be smaller, cost less and weigh less. They don't exist. OK, there are some decent ones like EF-M 11-22 and 22/2 but compared to the most popular L lenses, they have practically nothing. Which is a HUGE problem and a HUGE question mostly along the lines of WTF.
My bet is that this is all just bussiness. They were protecting full-farme with the EF L lenses. A big part of the world just would have stayed/switch at/to APS-C in case of the existence of EF-S L lenses. Which also means I'm not expecting much on the EF-M line. Very sad.
Writing this mostly because now I see people worry of not being able to use FF lenses on APS-C bodies. Hey people! That is wrong in he first place! It's very wrong that we had to get used to that!

 

[slclick]

Canon still has 47 less mounts than Nikon.

 

[bks54]

I believe Canon has clear design specifications for the EOS M system that they never have and never will stray from. Small, lightweight, mid-price APS-C bodies, small (60.9 mm diameter) lenses. You can adapt EF/EF-S if you wish. That is it. The system is nearly complete; perhaps they’ll release a few more wider aperture primes, and maybe an f4 zoom if they can make one only 60.9mm wide. It’s not meant to be a gateway drug to full- frame. I think an RF to EF-M adapter could be engineered for at least some of the new lenses but I don’t think Canon will bother because most EOS-M buyers won’t care.

 

[miketcool]

The reason Canon designed the RF mount is to support a full frame sensor.

And support future medium format Canon bodies.

 

[LSXPhotog]

That isn't the issue at all. It's the reverse.

Think about at the moment. You get an 80D and you buy some lenses. Let's look at someone who bought an EF-S 18-55, an EF-S 10-18, a 50mm f/1.4 and a 70-300 IS non-L zoom. Maybe your later lens choices were in part driven by knowing the lenses are future-proof if you decide to switch to FF.

Part of the incentive in upgrading from the 80D to full frame is that at least some of your lenses can continue to be used.

Now, if Canon had for example kept to the EF-M mount for full frame, in the future we could have the same situation, low cost 50mm f/1.8 or 1.4 EF-M lenses and a low cost 70-300 that would work with the EF-M but would also provide a full-frame image circle for when you upgraded to a FF camera.

Instead, you're stuck with APS-C only EF-M lenses, and the incentive to upgrade is far less. Suddenly the entry cost to FF is prohibitive.

This doens't affect Nikon because they have no APS-C mirrorless, and it doesn't affect Sony because they share the same mount.


Now, the advantages of the new mount are almost certainly worth the pain, but it is now going to be difficult to justify recommending EOS-M cameras to anyone because they will be stuck in an APS-C forever ecosystem.

Soooo you didn't read my post at all. You just got to that first sentence and began to reply. LOL I basically say the exact same thing and agree with you. Right now the only reason you would buy an EF-M lens is to stay small and know you can't use it on any other camera. If you plan to upgrade, you have to buy EF lenses because those will work on everything...knowing Canon, this is intentional.

 

[CanonFan]

As folks say, we are used to a world where EF-S doesn't work on FF , but APS-C can use both EF and EF-S.

I use an 80D with both EF-S and EF lenses --in fact my gear is close to what @jolyonralph said, only my zoom is a 70-300L series and I use an EF-S 17-55 f/2.8 which is terrific for low light (plus a few others in addition...) I am very happy with a crop sensor --if the 7D is upgraded I may go that way, or I may stay with the 80D which works hard and well for me. Being able to put both EF-S and EF lenses on my body gives me the best of both worlds.

I recently purchased an M50 for a second body, with the kit 18-45 M-series and an EF adapter. Love how small and light it is to be able to drop in a briefcase and leave it. It is like a miniaturized 80D. I have recently used it as my second camera at a couple of events, using my EF/S lenses particularly the 50mm 1.4 via adapter. This has worked well, though the small body would be quickly overwhelmed by really big lenses. I am tempted by the 22mm prime just to make it a very small street camera, and for sure it would be my preferred travel body. So I think there will continue to be a place for a limited selection of M lenses and adapters to allow, well, adaptation.

 

[fullstop]

so funny. all the drama, whrn everything is totally logical and clear.

Canon goes from 2 mounts in the mirrorslapper past to 2 mounts in the mirrorfree future. they do not compromise on lens mounts. Not in 1987, not today. one thing i really like about them.

1 perfectly chosen mount for compact APS-C cameras and a limited selection of decent and compact lenses. And 1 optimally chosen mount for great FF cameras and a full lens lineup to match. No problem whatsoever. and smooth transition from EF to RF.

Nikon looks set to go with only 1 mount for both FF and APS-C. thats one of the reasons they went with only 16mm FFD - to allow for "slim"
APS-C cameras as well.

but back to Canon: so we cant use EF- M crop lenses on full frame R cameras? OMG! who cares, it is a stupid idea to start with. dont tell me using a crop lens on FF sensor "in crop mode" yields better IQ than just doing the crop in post.

and as for RF to EF- M adapter, why should that not be possible? After all renown german maker Novoflex makes precise 2.5mm adapters for use of Nikon F lenses(46.5mm FFD) on Canon EF mount (44mm). they even manage to fit mechanical aperture control on the little contraption. so why should a canon RF to Canon EF-M 2mm adapter with wiring through and possibly a chip/firmware in it for protocol translation not be possible? although it also makes rather limited sense to stick a 28-70/2.0 on an EOS M50.

most of the adapter and cross-use angst postings are from folks worrying about residual/second-hand value of their (soon) legacy EF lenses. nothing else.

Canon is doing the right thing here and they do it boldly. wish they would be as bold with their mirrorfree FF cameras!

 

[Respinder]

Nikon may have 'officially' discontinued the 1 series in July, but the last camera in the series came out in 2015.

As for the EOS M being 'arguably more successful', the Nikon one was a commercial flop, the EOS M line is the best-selling MILC line globally. To claim the EOS M is 'arguably more successful' is disingenuous at best, but arguably just an asinine statement.

Hmm that's strange. According to NPD Group and Amazon, Sony is the best selling mirrorless, so not sure what you are talking about? While I know the Canon M series has been successful (i.e. same thing what I said above - not sure how it is asinine?), I never felt that it was going in any serious direction versus what Sony has been doing with E-mount (i.e. more lens selection, etc.).

I agree with what Traveller said as well - although Nikon 1 did fail, it did give Nikon a very clear path for what to do with mirrorless. With Canon, it is quite messy - very fragmented with many lines (EF, EF-S, EF-M, EF-RF), and the market simply cannot support it.

 

[neuroanatomist]

We should also consider that Canon may believe the 'problems' are minor and/or irrelevant.

Anecdotally, the use of EF lenses on APS-C bodies prior to a FF upgrade certainly occurs. There are examples on this forum, myself included. But is that typical/common? I know I'm far from typical – I had the 70-200/2.8L IS II, the 85/1.2L II, the 100-400L, and the 24-105/4L IS with the 7D, prior to getting the 5DII.

I wonder how many Canon APS-C owners upgrade to FF, how many have EF lenses when they do, and how many of those were lower IQ lenses that were replaced L lenses after the upgrade. But...whereas I can only wonder, Canon has the data. In light of those data, there maybe no real problem from their perspective.

 

[meywd]

There is a chance that both M and RF are special lenses mounts, while EF will stay as the general purpose mount, we will have 3 lineups:

M: small and compact, good for amateurs, travel, low weight constraints

R: Super lenses with mirrorless benefits, medium size, good for prosumers, backup to the main lineup

D (EF): the usual form for all users, currently DSLR and when the mirrorless is good enough convert to mirrorless with the same size, the pros will have their big and strong bodies with weather sealing and better handling with big whites

 

[fullstop]

With Canon, it is quite messy - very fragmented with many lines (EF, EF-S, EF-M, EF-RF), and the market simply cannot support it.

what?! it is totally clear cut. EF plus EF-S will transition to RF plus EF-M.
only during transitional period will there be current lenses in 4 mounts. EF-S will soon be legacy, EF will follow.

totally clear and logical. optimal mounts for different sensor sizes and camera types (different flange focal distance requirements).

there will be no mirrorfree FF bodies with EF nozzle. silver-colored "RF snout" is bad enough as it is.

 

[Respinder]

what?! it is totally clear cut. EF plus EF-S will transition to RF plus EF-M.
only during transitional period will there be current lenses in 4 mounts. EF-S will soon be legacy, EF will follow.

totally clear and logical. optimal mounts for different sensor sizes and camera types (different flange focal distance requirements).

there will be no mirrorfree FF bodies with EF nozzle. silver-colored "RF snout" is bad enough as it is.

I hope you're right

 

[bod]

In one of the other multitude of RF threads I raised exactly the same issue about "where does this leave the 7D?"

I think we all know the answer is that there won't be an APS-C sensor RF body, and those wanting to use lenses on both an M series and an R series camera are stuck with EF lenses and adaptors on both bodies.

Pleased to be reading this thread as I have been contemplating the same topics over the weekend since the details leaked about the new EOS R mount. In particular I want to move to EVF - mirrorless bodies but I am trying to work out a plan to replace my current FF (6D) plus APSC (7DII) bodies. As suggested as a possibility in the Canon news article my first thought was that the future will involve a high resolution mirrorless body which I can use in either a FF or cropped mode. I think it is likely that a high resolution RF body will be Canon's next release.

I also agree that I see the attraction of the M lineup as keeping it small and light. I had wondered which way Canon would go with the FF mirrorless but now knowing the RF lens lineup "smaller and lighter" is definitely not the case, Canon instead offering faster lenses.

I read the observations raised in the Canon news article about starting off in an M world and not being able to migrate to FF whilst continuing to use ones existing lenses. However I am not sure how large a sector this is of the customer base. For example users who want to stay small could just stick with the M lineup in view of the impressive performance of modern APSC sensors. Users like me ( I have the EOS M and EFM 22) who want a body which is easy to drop in a pocket will have one M body and limited lenses as an add on to their kit. For users who want to migrate to a FF system then the invested value in a few EFM lenses is not great anyway compared to the cost of purchasing a FF body and FF EF or RF lenses.

My question though is in response to your statement "there wont be an APSC sensor RF body". I agree that Canon could very well decide to offer just a high resolution RF body instead. However is there any technical reason why there could not be an APSC sensor RF body which could be used with RF lenses or EF lenses plus adaptor?