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

Jul 23, 2013
282
18
carlsmiller.com
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.
"FF EF-M" wasn't possible due to the diameter not accommodating a FF sensor from my understanding. Mounting FF lenses on crop (EF-M) wouldn't vignette.
 

zim

EOR R
Oct 18, 2011
1,863
53
I see the confusion with the writing here. We won't see RF lenses adapted for EF-M. This may create a problem for some shooters that would want an EOS M as a backup to an EOS R, you're going to have to have 2 sets of lenses. There are a lot of people that use a 7D2 as a backup to a 5D and EOS-1 series camera and can purchase one set of lenses to fit the needs of both.

Exactly, it's not about ditching any particular mount. It's about the flexibility a common mount gives.
Of course you can just stick with EF but will Canon? Do I really feel that Canon will introduce a new EF 50 1.4L IS or a EF 20 1.4L right now it doesn't feel like it to me.
Of course the easiest way to solve this is for Canon to be open and commit to supporting these lines they could and I think should publish a roadmap for their lens line-ups. I was really interested in and was waiting on the M5II but not now as I wouldn't be able to mount what seems to be Canon's replacement for the EF line.

I'm actually wondering if the other mirrorless still to be announced will actually be the replacement for the 7D, effectively a new line with the RF mount. To me that would make sense and be pretty exciting!
 
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VORON

EF 8-15mm F/4.0 L
Nov 23, 2017
12
11
33
St. Petersburg, Russia
EF-S also can't be used on EF and nobody batted an eye yet.
Back in 2004 you were perfectly right. In 2018, it's not like that anymore. Mounting a good APS-C lens on 30 MP FF body would give you around 12 MP. It is plenty. It could be an opportunity for seamless upgrading from cropped camera (especially considering the fact that the FF mirrorless is made a fully functional cropped camera with single button press). Also for video tasks the cropped lenses are more than enough.

So that's a definite mistake made by Canon and avoided by Sony.
 

Kit.

EOS 6D MK II
Apr 25, 2011
1,086
515
We won't see RF lenses adapted for EF-M. This may create a problem for some shooters that would want an EOS M as a backup to an EOS R, you're going to have to have 2 sets of lenses.
It's not a problem for Canon, though. Just the opposite: it is an opportunity for Canon to sell a more expensive body than EOS M.

the problem is not now but if canon wants to continue to compete in the APS-C mirrorless.With the A7000 coming out (supposedly) and the X-T3 coming out (supposedly) all with very high end mirrorless capabilities, what would canon use as a mount on a competitive 7D-like APS-C?
But will a "7D-like APS-C competitive" mirrorless be profitable to Canon? Especially if Canon needs to develop its own dedicated sensor (DPAF) for that niche camera.
 
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Jul 23, 2013
282
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carlsmiller.com
the mount depth with the lugs to hold the lens onto the mount requires a further depth of at least 3mm. you also have the electronic interconnects on both sides (mount and lens side). you also need the pin, lever and knob to remove the lens from the mount adapter.

then you have the fact that the mount is a 10mm greater diameter, and if a lens sits inside of the mount any, such as what the 35mm 1.8 RF does, it would not physically be able to mount on the adapter at all.

for a reverse adapter (RF body and EF-M lens), each EF-M lens is 61mm, it could not sit "inside" an RF mount adapter to get 2mm closer to the sensor.
Those are great points, but I don't think it's sufficient to say that it's impossible. I'd be comfortable betting you money that a 3rd party will tackle & figure it out if Canon doesnt have some solution.
 
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rsdofny

EOS M50
Oct 18, 2013
37
15
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.
I think that Canon still needs to fill the hole from 80D and 7D, which is not exactly compact, unless Canon wants to accelerate the price drop of ML FF to around $1000 sooner than expected.
 

Kit.

EOS 6D MK II
Apr 25, 2011
1,086
515
I think that Canon still needs to fill the hole from 80D and 7D, which is not exactly compact, unless Canon wants to accelerate the price drop of ML FF to around $1000 sooner than expected.
I think they can do at ~$1200 it if they put 6DII sensor there and sell EVF as an option (EVF-DC2 or a new version).
 

Mark D5 TEAM II

Proud N0ink 0wnz0r / crApple iFruitcake H4t3r
Mar 5, 2013
1,327
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Tleilax, Thalim Star System
Huh. Sony E-mount is narrower than Canon EF-M mount (46.1mm vs. 46.5mm). If the Sony E-mount cameras can take full-frame FE lenses why can't EF-M bodies? Also, Sony users are complaining about vignetting and problems with wide-angle lenses with E-mount. Sony could have avoided that problem by using Konica-Minolta's wider A-mount (49.7mm diameter), which was designed for 35mm full-frame, unlike the E-mount which was designed for NEX-style compact ILCs. So I can also argue that Sony painted themselves into a corner by using a lens mount designed for small cameras and shoehorning full-frame lenses for it. Look at the front of any Sony E-mount MILC without a lens and you can readily see that the full-frame sensor corners don't even clear the lens mount.
 

traveller

EOS 6D MK II
Jul 22, 2010
895
58
I wouldn’t write off an RF to EF-M mount adapter just yet. I would say there’s a good reason why Canon chose a 20mm flange focal distance for its full frame mirrorless mount rather than the 18mm of EF-M (and Sony FE mount), or something even shorter like Nikon Z mount. I suspect that the possibility of an adapter has something t do with it.
 
Jul 23, 2013
282
18
carlsmiller.com
I think forum posters are the largest percentage, by a mile. Pros will use what does the job best, sometimes that's an adaptor.
Simplified workflow is our mantra and in fast paced environments we don't want to move an adapter to each new lens we want to use. We could let the adapter live on our camera body but then as soon as one RF lens enters our kit that is no longer possible (i.e. I know I wont get any RF lenses until a complete kit swap-out is possible). It's just messy and clumsy and Canon either needs to pump out RF lenses like crazy or offer a EF mirrorless in the interim.
 

neuroanatomist

I post too Much on Here!!
Jul 21, 2010
24,318
1,667
So why exactly can't RF lenses be adapted to EF-M? The article states they can't with zero justification. RF flange of 20mm which is > than EF-M flange of 18mm.
Technically they probably can, with an EdMika-like conversion. Certainly not a commercially viable solution.

I'm really puzzled by Canon's disregard of the EOS M to EOS R upgrade path via pre-buying lenses.

Still, perhaps this is an indication that Canon doesn't intend a full RF lens lineup, and will keep the RF line limited in scope and eventually release EF FF MILCs.
 

jolyonralph

Kodak Brownie
Aug 25, 2015
1,085
294
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London, UK
www.everyothershot.com
Still, perhaps this is an indication that Canon doesn't intend a full RF lens lineup, and will keep the RF line limited in scope and eventually release EF FF MILCs.
The only way that might happen is if RF is a complete and utter disaster for Canon and they have no choice but to go back.

But I see no reason to think that, and they would have absolutely no reason to launch EF FF mirrorless cameras which would be a distraction from their new RF lens system.

I'll happily put money on the forthcoming "Pro" mirrorless DSLR being RF mount. There's NO way they'd launch a 'semi-pro' model with a 28-70 f/2.0 lens and then launch a 'pro' model that can't use this new superlens.

The 28-70 is going to be a ~$3K lens minimum because 95mm lens elements don't come cheap. Closest thing to it in complexity in the current lineup is probably the EF 11-24. Maybe I'm wrong, and I'd love to be, but unless the R body is overpriced I would pretty much expect this lens to cost more than the body.

However, it won't be as much as the Nikon NOCT 0.95 nonsense :)
 

dak723

EOS 6D MK II
Oct 26, 2013
1,141
434
Hmmm. Crop Mirrorless Canon = M mount. FF Mirroless Canon = RF mount. My guess is that Canon understands that (forum dwellers not withsatnding) very few folks will want RF lenses for their M series cameras and vice versa. Considering the huge size difference in both cameras and lenes, they regard these two mirrorless systems as completely separate. The so-called "upgrade path from crop to FF" might include so few people as to be a non factor. I am interested in the new RF camera and also own the M. I would have absolutely no interest in buying an RF lens for my M5 due to size and weight.
 

olympus593

I'm New Here
Oct 12, 2015
15
1
Because of the difference in between the two mount registration distances (the distance between the sensor and the mount flange) of only 2mm, there will never be an EF-M camera to RF lens adapter
Cut the crap.

Pentax PK mount flange mount distance is 45.46mm, 1.46mm larger than EF (44mm) and there are many adapters out there, some with onboard electronics for compatibility with newer lenses. I use a "dumb" one with a PK 50mm f/1.2.
 
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miketcool

EOS T7i
Jun 29, 2017
91
141
Future M-series APS-C bodies could come with an RF mount that allows M lenses to sit inside. The current complaint is about using crop-sensor lenses on FF bodies. I’d put money on Canon for future M bodies that work with EF-M lenses.
 

Adelino

EOS RP
Jan 21, 2015
296
148
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.
You just named my exact lens purchase history and FF migration process and reasoning.
 
Jul 23, 2013
282
18
carlsmiller.com
I'll happily put money on the forthcoming "Pro" mirrorless DSLR being RF mount. There's NO way they'd launch a 'semi-pro' model with a 28-70 f/2.0 lens and then launch a 'pro' model that can't use this new superlens.
That's how I feel too. As much as I'd love an EF mirrorless, the RF lenses point to full-steam ahead on RF. I think the official word from Canon will be "we're developing both simultaneously" but that'll mean new paint job EF lenses as the RF line is matured.
 
Nov 10, 2016
32
13
I don't agree with the idea of an upgrade path from EOS-M to EOS-RF. I purchased an M50 because it checked off enough of the boxes to make the purchase. It's a small, light package that takes great images with small, light lenses. Although I have the EF adapter, I rarely use it. I know my L glass would increase image quality but my 24-70 f/2.8 L II and 5D IV seem to be made for each other, so why break up a good act;-) This is all to say that Canon knows their market segments. Very few consumers will look at the EOS-M as a complement or backup to EOS-EF or RF. The vast numbers of consumers want an elegant camera system that just works.

The mirror slappers will eventually go away and EF with it. When the time to switch is inevitable, we will all put the old stuff on the shelf with the Brownie.
 
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