Adapter for Canon DSLRs to use RF lenses?

[dmschnirch]

Will Canon develop an adapter so RF lenses can be used on a DLSR? Would such an adapter allow a 5DMK4 or 1DXII be able to use the new 28-70mm f2L lens?

New to the forum so not sure if this has been asked yet or would even be possible

 

[AlanF]

It has been asked and it is not practically currently possible because the RF lens has to be closer to the sensor than the distance between the DSLR sensor and the EF mount.

 

[jolyonralph]

It's more than just the flange distance. The interface in the RF lens is far more modern than the EF interface.

I'm not saying it's impossible, but it's as close to impossible as makes no difference.

 

[AlanF]

It can't be ruled out for the future. We don't the nature of the flange interface and it might be possible to have some electrical compatibility as you can mount an EF on an RF flange so vice versa might be on. It also might be possible to have a lens system in the adaptor to compensate, or future generations of EF bodies might have a sensor that can switch between two positions.

 

[jolyonralph]

It would probably be possible to build a manual-focus adaptor to fit RF lenses to an EF mount with some glass in it, but to do so you'd probably add a stop or so of light loss and/or huge image degradation, so why bother?

But from what I've read so far about the new high-speed data interface it would need some serious electronics in the adaptor (ie a DIGIC chip or similar) to deal with autofocus.

So, no, it'll never happen.

 

[koenkooi]

It would probably be possible to build a manual-focus adaptor to fit RF lenses to an EF mount [..]

Since all RF lenses are focus-by-wire, who is in charge of issuing focus commands, the lens or the camera, when turning the focus ring? If it's the camera, RF lenses would be fixed-focus on such an adapter.

 

[bbb34]

It can be done with the following setup, and a bit of fine tuning.

 

[Mt Spokane Photography]

We may see EF lenses and DSLR's in the future with RF communcations, but its unlikely. A dapting a RF lens to EF would require optics in the adapter which will decrease quality. In the long run, it would be cheaper to replace the DSLR with a R camera.

 

[dmschnirch]

Thank you everyone for your replies. So to be clear, even if the adapter was made like an extension tube for maco photography (guess Canon has those), it would be safe to assume that the RF lens configuration would not be compatible with the current EF mount.

 

[mirage]

So to be clear, even if the adapter was made like an extension tube for maco photography (guess Canon has those),

not quite ... there are 2 major obstacles:
1.) EF mount has 44mm flange focal distance and RF lenses are designed for 20mm FFD [R-mount]. Therefore an adapter would need to have optical elements (glass lenses), which costs some IQ.
2.) Mount protocol/communication issues for RF to EF

We cannot imagine we would ever see an RF-EF adapter from Canon. Maybe some 3rd party company will attempt it, but especially issue #2 might be fairly tough to solve with reverse engineering.

 

[Mt Spokane Photography]

Thank you everyone for your replies. So to be clear, even if the adapter was made like an extension tube for maco photography (guess Canon has those), it would be safe to assume that the RF lens configuration would not be compatible with the current EF mount.

A extension tube would not work, the rear of the lens needs to sit closer to the sensor by over 50%. Only a optical element could do this, thd that takes space too. Its just not practical.

 

[AlanF]

The take home message is that if you want to use an RF lens then get an EOS R.

 

[Ozarker]

No. Not gonna happen.

 

[mrzero]

The fact that Canon even built and produced a 28-70 f/2 zoom lens suggests that they are committed to the RF mount enough that we will see 5D and 1D type R bodies in the future. Until then, the reviews of the EOS R sound like it will do a fine job of capturing images with this lens. I have a feeling the rental houses will have a hard time keeping them in stock.