Here is what Canon is announcing next, including the EOS R7, EOS R10 and RF-S lenses [CR3]

I don't know about the technicalities or physics involved, so do ignore me if I'm wrong. But would it be feasible for RF-S to simply be the M mount with a new badge? And maybe an adaptor to use RF (and legacy ef-s/Ef as you can already do with ef-m) glass?

It could potentially be a way to get M users using R cameras without having to buy a suite of new lenses as well.

I could of course be talking out of my posterior!
 
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Time will tell what Canon decides to do about the M system, which is still selling quite well.

For those (like me) who sometimes need a very small and lightweight ILC, the R10 would have to be extremely small and the rumoured RF-S lenses would have to be smaller than the current non-L RF lenses to replace the M-system. I obviously don't have an R10, but I have an RF 50 1.8 and an EF-M 22 2 in front of me. Lenses the size of the RF 50 are too large for the specific purposes I use them.
Might well be that I'll have to replace the M6 with a smartphone once it breaks :oops: Or use a camera from another brand, if such cameras still exist then
The R crop camera is going to be bigger, more expensive and heavier than the M system. Watch the EF-S lenses disappear completely, followed by the adaptors.
 
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Some thoughts...

It was suggested before Canon might make a crop RF mount camera to see whether customers would prefer it over the EOS M line. If it doesn't catch, Canon can scrap it. The crop lenses would be shared with the R7, and a cheap redesign of existing EF-S / EF-M lenses, saving costs.

The 24 MP sensor could be recycled from the 850D or R3, saving on cost. It would have a reach advantage over [higher pixel density than] the R5, and so offer some benefit.

As a speculation, Canon might have customer feedback showing interest in a crop RF camera, either as an addition to existing FF RF camera, or as offering an upgrade path to new customers (= having no camera, or interested in switching from other manufacturers).
The 24 MP sensor could be recycled from the M50, hopefully updated.
 
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HMC11

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I don't know about the technicalities or physics involved, so do ignore me if I'm wrong. But would it be feasible for RF-S to simply be the M mount with a new badge? And maybe an adaptor to use RF (and legacy ef-s/Ef as you can already do with ef-m) glass?

It could potentially be a way to get M users using R cameras without having to buy a suite of new lenses as well.

I could of course be talking out of my posterior!
You have raised an interesting proposition :). The flange distances of the RF and EF-M mounts are 20mm and 18mm respectively. I am guessing simplistically that this broadly means having to house the EF-M optics assembly within a larger diameter casing and position the assembly 2mm closer to the mount (backend of the lens). Not sure if that would make the optics stick out a little at the backend, but 2mm seems doable. However, even if it is possible, it doesn't seem to make sense for Canon to do that rather than design new lenses to take advantage of the RF mount (larger diameter), especially in anticipation of higher resolution future APSC sensors, i.e. the RF-S lenses would probably be designed to resolve higher pixel density sensors. For example, the current lineup of RF 'L' lenses can probably work well for 100mp FF sensors (or about 38mp for APSC sensors).
 
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bbasiaga

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You have raised an interesting proposition :). The flange distances of the RF and EF-M mounts are 20mm and 18mm respectively. I am guessing simplistically that this broadly means having to house the EF-M optics assembly within a larger diameter casing and position the assembly 2mm closer to the mount (backend of the lens). Not sure if that would make the optics stick out a little at the backend, but 2mm seems doable. However, even if it is possible, it doesn't seem to make sense for Canon to that rather than design new lenses to take advantage of the RF mount (larger diameter), especially in anticipation of higher resolution future APSC sensors, i.e. the RF-S lenses would probably be designed to resolve higher pixel density sensors. For example, the current lineup of RF 'L' lenses can probably work well for 100mp FF sensors (or about 38mp for APSC sensors).
The OD of the M lenses is greater than the ID of the RF mount (this is just me looking at the M lenses I have and the R6 body I have). So there is no practical way to slip them inside, plus have room for an adapter. Sadly, this means that any M lens on an RF body would have to have an optical adapter - a piece of glass in the adapter to extend the back focus distance to work with the RF for factor. This would not necessarily be the end of the world, but I'm guessing that adapter would be more expensive than some M lenses are. It could create some options too, such as a speed booster as well. But again, that could be several hundred dollar adapter and I'm not sure there would be enough demand.

This whole though process was gone through when the RF mount was announced years ago. Which is where the speculation that the M mount was on it way out started. Didn't seem to make sense to have two mirrorless platforms, and by making RF 20mm vs 18mm flange distance they effectively (or cost effectively) eliminated the possibility of compatibility between the two.

Just have to wait and see what happens.
 
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The OD of the M lenses is greater than the ID of the RF mount (this is just me looking at the M lenses I have and the R6 body I have). So there is no practical way to slip them inside, plus have room for an adapter. Sadly, this means that any M lens on an RF body would have to have an optical adapter - a piece of glass in the adapter to extend the back focus distance to work with the RF for factor. This would not necessarily be the end of the world, but I'm guessing that adapter would be more expensive than some M lenses are. It could create some options too, such as a speed booster as well. But again, that could be several hundred dollar adapter and I'm not sure there would be enough demand.

This whole though process was gone through when the RF mount was announced years ago. Which is where the speculation that the M mount was on it way out started. Didn't seem to make sense to have two mirrorless platforms, and by making RF 20mm vs 18mm flange distance they effectively (or cost effectively) eliminated the possibility of compatibility between the two.

Just have to wait and see what happens.
I think what @HMC11 means is not adapting production EF-M lenses for the R mount, but rather Canon manufacturing new lenses with the EF-M optical elements in a new housing sized for the RF mount. Optically, I agree that is possible. The 2mm difference nearly fits within the mount thickness, and would not protrude far enough into the body to cause any issues. Basically, it would result in a new set of lenses without Canon making a significant investment in design (reminiscent of the new RF 800/5.6 and 1200/8, where they essentially inserted a 2x TC behind the existing 400/2.8 and 600/4 lenses, which themselves are just reused EF designs with an RF adapter bolted on).
 
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reefroamer

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Sad that the only lenses announced are kit lenses. Was hoping for a compelling telezoom to be released with the R7.
I think the $650 RF 100-400 would be the ideal, affordable and small tele zoo for crop sensor bodies. And the RF 24-105 is quite compact, light and affordable. No, they’re not M-small, but M-small comes with quite few limitations. Other than ultrawide, Canon already covers 16-400mm with good, affordable small lenses, thar are well-suited for the rumored R10, IMHO.
 
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I think what @HMC11 means is not adapting production EF-M lenses for the R mount, but rather Canon manufacturing new lenses with the EF-M optical elements in a new housing sized for the RF mount. Optically, I agree that is possible. The 2mm difference nearly fits within the mount thickness, and would not protrude far enough into the body to cause any issues. Basically, it would result in a new set of lenses without Canon making a significant investment in design (reminiscent of the new RF 800/5.6 and 1200/8, where they essentially inserted a 2x TC behind the existing 400/2.8 and 600/4 lenses, which themselves are just reused EF designs with an RF adapter bolted on).
This isn't quite what I was getting at in my original proposition - I doubt RF users would be that concerned with EF-M glass and I realise going the other way round, to use EF-M on RF isn't at all practical or cost-effective.

My thought was what if RF-S was simply EF-M with a new name, so you could use existing EF-M lenses and also RF lenses via an adaptor - exactly the same way as EOSM can use EF and EF-S lenses. Of course, this does mean you wouldn't be able to take your RF-S glass with you if you wanted to "upgrade" to FF. Similar (compatibility wise, not physically) to EF-S and EF in that regard.
 
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I think what @HMC11 means is not adapting production EF-M lenses for the R mount, but rather Canon manufacturing new lenses with the EF-M optical elements in a new housing sized for the RF mount. Optically, I agree that is possible. The 2mm difference nearly fits within the mount thickness, and would not protrude far enough into the body to cause any issues. Basically, it would result in a new set of lenses without Canon making a significant investment in design (reminiscent of the new RF 800/5.6 and 1200/8, where they essentially inserted a 2x TC behind the existing 400/2.8 and 600/4 lenses, which themselves are just reused EF designs with an RF adapter bolted on).
I do not remember a Canon announcement that said the RF800 and RF1200 were re-purposed EF lenses with 2x TC. They left that for us to figure out.
They may do that with the M lenses, but we will have to figure out what they did for ourselves. They will just release a group of small compact RF-S lenses.
I am not sure what this type of Engineering is called: "streamlined", "repurposed engineering", "value engineering" or "lipstick on a pig engineering". Most likely it would be "accountant engineering" or "bottom line engineering".
 
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This isn't quite what I was getting at in my original proposition - I doubt RF users would be that concerned with EF-M glass and I realise going the other way round, to use EF-M on RF isn't at all practical or cost-effective.

My thought was what if RF-S was simply EF-M with a new name, so you could use existing EF-M lenses and also RF lenses via an adaptor - exactly the same way as EOSM can use EF and EF-S lenses. Of course, this does mean you wouldn't be able to take your RF-S glass with you if you wanted to "upgrade" to FF. Similar (compatibility wise, not physically) to EF-S and EF in that regard.
What you're suggesting is not really feasible.

Using existing EF-M lenses on an RF mount would require an adapter with optics, and likely result in substantial image degradation.

EF and EF-S lenses have a longer flange distance (44mm) than RF (20mm) or EF-M (18mm). That allows room for an adapter that is really just a spacer, without optics. Mounting an RF lens on an M body means a 2mm adapter, not really practical to use and no one has made one (nor, I suspect, will anyone). Mounting an EF-M lens on an R body would require the lens to sit 2mm inside the body, and that's not possible. Thus, any adapter would need optical elements like the old FD-to-EOS adapter.
 
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Blue Zurich

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I think the $650 RF 100-400 would be the ideal, affordable and small tele zoo for crop sensor bodies. And the RF 24-105 is quite compact, light and affordable. No, they’re not M-small, but M-small comes with quite few limitations. Other than ultrawide, Canon already covers 16-400mm with good, affordable small lenses, thar are well-suited for the rumored R10, IMHO.
Exactly, many are throwing around the incorrect premise that Canon has no small lenses which would make for balanced R Crop bodies. Rubbish. RF 16, RF 50, 35 STM, 85 STM, 24-105 STM, even the RF 70-200L f/4 would work on a body just a smidge larger than an M5. I could also see some pancakes in the future for crop RF. All these and far greater optics to go along with it. Sounds like pure win.
 
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HMC11

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This isn't quite what I was getting at in my original proposition - I doubt RF users would be that concerned with EF-M glass and I realise going the other way round, to use EF-M on RF isn't at all practical or cost-effective.

My thought was what if RF-S was simply EF-M with a new name, so you could use existing EF-M lenses and also RF lenses via an adaptor - exactly the same way as EOSM can use EF and EF-S lenses. Of course, this does mean you wouldn't be able to take your RF-S glass with you if you wanted to "upgrade" to FF. Similar (compatibility wise, not physically) to EF-S and EF in that regard.
To adapt EF-M lenses for RF mount would require an adapter with optical elements as the Flange distance of the EF-M is actually 2mm shorter. This could add not inconsiderable (cf EF-M lenses) weight and length to the whole setup, negating the light weight and small size advantages of the EM-M system. On the other hand, adapting EF & EF-S lenses on the M and RF mount are much easier, as the adapter is essentially just a spacer (with electronics that allow for communication between the lens and the camera body). Using adapter with optical elements to adapt lenses for shorter flange distance to lenses for longer flange distance system does not seem to have happened yet, as far as I know, for the major camera companies.
 
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