RF to M Adapter?

[pigufuvi]

Ok, I have an adapter to use my EF and EF-S lenses on my M and M50. If I bought an R I could also get an adapter to use the same lenses. The question is whether there will be an adapter to use these wonderful RF-mount lenses on M body cameras? Is it possible geometrically?

I have already decided I probably won't be buying any more EF lenses as the future looks RF and M. The eventual replacements for my 5D3 and SL1 will likely be mirrorless. But will there be a divide between the two mirrorless lines?

[Waddizzle]

The RF mount and EFM mount are mutually incompatible.  It is not possible to make an adapter.

[Lotus7]

Possible: Maybe, Practical: Not

Since the flange to focal plane distance for the EFM mount is 18mm and for the RF mount is 20mm it is theoretically and physically possible to design a mecahnical (only) adapter for some RF lenses to fit a EFM body with focus extending to infinity. It can be done for the RF lenses which have smaller diameter rear elements but not for the faster models with large diameter exit optics. The EFM "throat" diameter is 7 mm smaller.  However the 2mm differential flange space does NOT allow for correct positioning of the electrical contact interface between the EFM body and a RF lens.

Since RF lenses have electronic "fly by wire" focus and aperture control (even in manual mode) without the elecronic interface the RF lens would be fixed at infinity focus and wide-open aperture. 

Bottom Line:  Don't expect to ever see a RF to EFM adapter, but if you do, be sure to understand its major limitations.

[John_SD]

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@Waddizzle wrote:

The RF mount and EFM mount are mutually incompatible.  It is not possible to make an adapter.

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Agreed. Even if it were technically possible, I can't imagine Canon pouring that kind of time and money into a system that may be phased out, given their full-bore committment to the R system itself. Furthermore, I am of the mind that if one really wants to use RF lenses, then you should buy into the R system. 

[Tronhard]

To me the EM and RF mounts are designed for completely different market spaces.  Whether the EM mount continued or not is certainly up for debate, but it makes no sense (nor physical practicality) for a converter mount to be created.

[ebiggs1]

"...Whether the EM mount continued or not is certainly up for debate,..."

Or logic, Trevor the writing is on the wall if you will just read it. Not only M but EF-S and EF.

[Tronhard]

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@ebiggs1 wrote:

"...Whether the EM mount continued or not is certainly up for debate,..."

Or logic, Trevor the writing is on the wall if you will just read it. Not only M but EF-S and EF.

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Ernie my friend, you know I respect your opinion, and it may well be correct.  I am just waiting to see how things develop.  I am sure in the long run your prediction will be correct, but I wonder if it will be evolution or revolution?

[ebiggs1]

"... I wonder if it will be evolution or revolution?"

I will guess poor sales did the trick.

Plus things change as technology grows. Perhaps Canon saw some difficulties advancing the M series. That is what killed the FD mount. Already went through that!

[Lotus7]

Not to hijack this thread, but since the FD Series was mantioned by ebiggs1:

They are such beautifully crafted lenses, and often optically quite good, but today have little financial value.  I never parted with my collection of FD primes.  I'm happy to report that the  $35 FotodioX Pro FD-EOS R Adapter is beautifully made, fits perfectly and that all my old FD's work fine on the R5, R and RP.  The FD 24 mm was always one of my favorites, capable of producing sharp 20X30 prints on a F1 Pan-X B&W negative.

Although I love the RFs, I fined that sometimes being constranied to manual focus and manual aperture control lets one relax and concentrate more on really thinking about what you are trying to convey in a shot. 

[ebiggs1]

No teacher like history and experience, my friend.