DPReview.com is closing April 10th - Find out more

RF lenses on other cameras

Started Jul 18, 2019 | Discussions
gazza73
gazza73 Senior Member • Posts: 1,015
RF lenses on other cameras

Can a Canon RF lenses be adapted to a Sony A7 series Body or are their flange distances too similar?

Canon RF 70-200mm F2.8L IS USM
If you believe there are incorrect tags, please send us this post using our feedback form.
joenj Contributing Member • Posts: 911
Re: RF lenses on other cameras
1

gazza73 wrote:

Can a Canon RF lenses be adapted to a Sony A7 series Body or are their flange distances too similar?

A neccesary condition to be able to use a lens of camera A on camera B is that flange range of camera A is larger than flange range of camera B.

gazza73
OP gazza73 Senior Member • Posts: 1,015
Re: RF lenses on other cameras

Are all lenses designed for mirrorless practically the same then and no room for adapters?

joenj Contributing Member • Posts: 911
Re: RF lenses on other cameras

gazza73 wrote:

Are all lenses designed for mirrorless practically the same then and no room for adapters?

Flange range of Sony E-mount is 18mm. Canon RF is 20mm. So, while an RF lens on a Sony E-mount camera could be possible, a Sony E-mount lens on a Canon RF mount camera is not.

Sittatunga Veteran Member • Posts: 5,406
Re: RF lenses on other cameras
1

joenj wrote:

gazza73 wrote:

Are all lenses designed for mirrorless practically the same then and no room for adapters?

Flange range of Sony E-mount is 18mm. Canon RF is 20mm. So, while an RF lens on a Sony E-mount camera could be possible, a Sony E-mount lens on a Canon RF mount camera is not.

The throat diameter of the E mount is 46.1mm.  The outside diameter of the RF lens bayonet flanges is 56¼mm and they extend slightly closer than 16½mm to the plane on the sensor.  The only chance of mounting an RF lens to E mount or Z mount and getting infinity focus is by way of a slightly short teleconverter.

quiquae Senior Member • Posts: 2,265
Re: RF lenses on other cameras
4

joenj wrote:

gazza73 wrote:

Are all lenses designed for mirrorless practically the same then and no room for adapters?

Flange range of Sony E-mount is 18mm. Canon RF is 20mm. So, while an RF lens on a Sony E-mount camera could be possible, a Sony E-mount lens on a Canon RF mount camera is not.

Flange distance is only one part of the story. There are also:

1) The mount diameter, which is 54mm for RF and 46mm for E, meaning that an RF-E mount adapter has to expand 3mm on all sides in a space of 2mm to allow the adapter to physically fit on the RF mount lens. And then there is the matter of the RF mount lenses being optically designed around having such a large opening--it is likely that such an adapter would cause really ugly vignetting on any native RF lens. (Third party lenses are probably OK, as they would almost always be designed with either DSLR mounts or E mount in mind.)

2) Flange-back distance. RF lenses are sometimes designed with a significant amount of optics behind the mount bayonet--the rear element of the RF 35mm, for example, protrudes several millimeters backwards. In other words, such a lens needs to protrude into the body of an E mount camera when adapted. Good luck getting that to work, especially combined with the previous point.

If anything, the other way around--E mount lenses on RF--is more likely. The E mount is narrower by 6mm than the RF mount, and there is copious amount of empty space inside the RF mount cavity (which is sometimes used by native RF lenses, as mentioned earlier.) This space may, in theory, allow for an E-RF mount adapter to be sunk into the mount cavity. I doubt we would ever see such an adapter, both for technical and commercial reasons*, but it appears to be physically not impossible.

* Sigma and Tamron are all but certain to offer RF mount versions of their lenses in the near future, and the only real reason to use Sony lenses over EF or RF equivalents in the foreseeable future is if you already have a set of E mount lenses (Canon lenses are at least equal to Sony ones in most cases, and often cheaper). And if you do have a bunch of Sony lenses, why not just use a Sony body?

 quiquae's gear list:quiquae's gear list
Canon EOS R5 Canon EF 100mm F2.8L Macro IS USM Canon EF 70-200mm F4L IS USM Canon EF 16-35mm F4L IS USM Canon EF 100-400mm F4.5-5.6L IS II +6 more
lawny13 Veteran Member • Posts: 3,132
Re: RF lenses on other cameras
1

quiquae wrote:

joenj wrote:

gazza73 wrote:

Are all lenses designed for mirrorless practically the same then and no room for adapters?

Flange range of Sony E-mount is 18mm. Canon RF is 20mm. So, while an RF lens on a Sony E-mount camera could be possible, a Sony E-mount lens on a Canon RF mount camera is not.

Flange distance is only one part of the story. There are also:

1) The mount diameter, which is 54mm for RF and 46mm for E, meaning that an RF-E mount adapter has to expand 3mm on all sides in a space of 2mm to allow the adapter to physically fit on the RF mount lens. And then there is the matter of the RF mount lenses being optically designed around having such a large opening--it is likely that such an adapter would cause really ugly vignetting on any native RF lens. (Third party lenses are probably OK, as they would almost always be designed with either DSLR mounts or E mount in mind.)

2) Flange-back distance. RF lenses are sometimes designed with a significant amount of optics behind the mount bayonet--the rear element of the RF 35mm, for example, protrudes several millimeters backwards. In other words, such a lens needs to protrude into the body of an E mount camera when adapted. Good luck getting that to work, especially combined with the previous point.

If anything, the other way around--E mount lenses on RF--is more likely. The E mount is narrower by 6mm than the RF mount, and there is copious amount of empty space inside the RF mount cavity (which is sometimes used by native RF lenses, as mentioned earlier.) This space may, in theory, allow for an E-RF mount adapter to be sunk into the mount cavity. I doubt we would ever see such an adapter, both for technical and commercial reasons*, but it appears to be physically not impossible.

* Sigma and Tamron are all but certain to offer RF mount versions of their lenses in the near future, and the only real reason to use Sony lenses over EF or RF equivalents in the foreseeable future is if you already have a set of E mount lenses (Canon lenses are at least equal to Sony ones in most cases, and often cheaper). And if you do have a bunch of Sony lenses, why not just use a Sony body?

There is another point to be added. 
From what I gather from many people EF adapted lenses don't give you full EF lens functionality. So though sony bodies are "better" than camera bodies... 
EF lens + Alpha body combo < EF lens on Canon body (maybe even <<, definitely when it comes to video). 
I really don't see why this won't be the case for RF lenses. What is the point to specifically go through the trouble of getting RF lenses to adapt to sony if you will be missing a major chunk of what that camera can do. I mean the only reason would be for something sony don't have. Like the 50 f1.2. And if you went that way, it would be a shame to place a 2.5k lens like that on a body that essentially cripples the lens. 
Just my 2c

bullet1 Veteran Member • Posts: 7,339
Re: RF lenses on other cameras

lawny13 wrote:

quiquae wrote:

joenj wrote:

gazza73 wrote:

Are all lenses designed for mirrorless practically the same then and no room for adapters?

Flange range of Sony E-mount is 18mm. Canon RF is 20mm. So, while an RF lens on a Sony E-mount camera could be possible, a Sony E-mount lens on a Canon RF mount camera is not.

Flange distance is only one part of the story. There are also:

1) The mount diameter, which is 54mm for RF and 46mm for E, meaning that an RF-E mount adapter has to expand 3mm on all sides in a space of 2mm to allow the adapter to physically fit on the RF mount lens. And then there is the matter of the RF mount lenses being optically designed around having such a large opening--it is likely that such an adapter would cause really ugly vignetting on any native RF lens. (Third party lenses are probably OK, as they would almost always be designed with either DSLR mounts or E mount in mind.)

2) Flange-back distance. RF lenses are sometimes designed with a significant amount of optics behind the mount bayonet--the rear element of the RF 35mm, for example, protrudes several millimeters backwards. In other words, such a lens needs to protrude into the body of an E mount camera when adapted. Good luck getting that to work, especially combined with the previous point.

If anything, the other way around--E mount lenses on RF--is more likely. The E mount is narrower by 6mm than the RF mount, and there is copious amount of empty space inside the RF mount cavity (which is sometimes used by native RF lenses, as mentioned earlier.) This space may, in theory, allow for an E-RF mount adapter to be sunk into the mount cavity. I doubt we would ever see such an adapter, both for technical and commercial reasons*, but it appears to be physically not impossible.

* Sigma and Tamron are all but certain to offer RF mount versions of their lenses in the near future, and the only real reason to use Sony lenses over EF or RF equivalents in the foreseeable future is if you already have a set of E mount lenses (Canon lenses are at least equal to Sony ones in most cases, and often cheaper). And if you do have a bunch of Sony lenses, why not just use a Sony body?

There is another point to be added.
From what I gather from many people EF adapted lenses don't give you full EF lens functionality. So though sony bodies are "better" than camera bodies...
EF lens + Alpha body combo < EF lens on Canon body (maybe even <<, definitely when it comes to video).

This is so not true  My Canon EF lenses perform better in many cases on the Sony A7III than on my 6D, especially with the 135mm F2L and 70-200mm F2.8L IS.  They focus more accurately for indoor event shots wide open.  With IBIS, the 135mm F2 can be shot handheld at much lower shutter speeds such as 1/40 sec.  You should really try them personally to decide. This is why I wanted to get the R later this year to achieve better use of my EF lenses.

I really don't see why this won't be the case for RF lenses. What is the point to specifically go through the trouble of getting RF lenses to adapt to sony if you will be missing a major chunk of what that camera can do. I mean the only reason would be for something sony don't have. Like the 50 f1.2. And if you went that way, it would be a shame to place a 2.5k lens like that on a body that essentially cripples the lens.
Just my 2c

-- hide signature --

Nelson

 bullet1's gear list:bullet1's gear list
Panasonic FZ1000 Canon PowerShot G5 X Sony a7 III Canon EOS R Canon EOS R7 +20 more
lawny13 Veteran Member • Posts: 3,132
Re: RF lenses on other cameras

bullet1 wrote:

lawny13 wrote:

quiquae wrote:

joenj wrote:

gazza73 wrote:

Are all lenses designed for mirrorless practically the same then and no room for adapters?

Flange range of Sony E-mount is 18mm. Canon RF is 20mm. So, while an RF lens on a Sony E-mount camera could be possible, a Sony E-mount lens on a Canon RF mount camera is not.

Flange distance is only one part of the story. There are also:

1) The mount diameter, which is 54mm for RF and 46mm for E, meaning that an RF-E mount adapter has to expand 3mm on all sides in a space of 2mm to allow the adapter to physically fit on the RF mount lens. And then there is the matter of the RF mount lenses being optically designed around having such a large opening--it is likely that such an adapter would cause really ugly vignetting on any native RF lens. (Third party lenses are probably OK, as they would almost always be designed with either DSLR mounts or E mount in mind.)

2) Flange-back distance. RF lenses are sometimes designed with a significant amount of optics behind the mount bayonet--the rear element of the RF 35mm, for example, protrudes several millimeters backwards. In other words, such a lens needs to protrude into the body of an E mount camera when adapted. Good luck getting that to work, especially combined with the previous point.

If anything, the other way around--E mount lenses on RF--is more likely. The E mount is narrower by 6mm than the RF mount, and there is copious amount of empty space inside the RF mount cavity (which is sometimes used by native RF lenses, as mentioned earlier.) This space may, in theory, allow for an E-RF mount adapter to be sunk into the mount cavity. I doubt we would ever see such an adapter, both for technical and commercial reasons*, but it appears to be physically not impossible.

* Sigma and Tamron are all but certain to offer RF mount versions of their lenses in the near future, and the only real reason to use Sony lenses over EF or RF equivalents in the foreseeable future is if you already have a set of E mount lenses (Canon lenses are at least equal to Sony ones in most cases, and often cheaper). And if you do have a bunch of Sony lenses, why not just use a Sony body?

There is another point to be added.
From what I gather from many people EF adapted lenses don't give you full EF lens functionality. So though sony bodies are "better" than camera bodies...
EF lens + Alpha body combo < EF lens on Canon body (maybe even <<, definitely when it comes to video).

This is so not true My Canon EF lenses perform better in many cases on the Sony A7III than on my 6D, especially with the 135mm F2L and 70-200mm F2.8L IS. They focus more accurately for indoor event shots wide open. With IBIS, the 135mm F2 can be shot handheld at much lower shutter speeds such as 1/40 sec. You should really try them personally to decide. This is why I wanted to get the R later this year to achieve better use of my EF lenses.

i did try them personally. But when it comes to adapting to Sony I have to admit it is a bit of a moving target. Having tried them on the A7II is not the same as the A7III and then not the same with subsequent FW updates. So the tricky thing about Sony (for better or worse) is the complexity of keeping track of all this.

But... you bring up another bunch of separate aspects. On sensor focusing vs separate AF sensor (DSLRs) is not a lens issue is it? Same goes with IBiS.

With adapted lenses in low light I had issues. Also depending on what settings you have with the MB adapter you had certain Sony camera functions. And in my experience video was annoyingly frustrating.

But most definitely adapted EF to R was more consistent and better than adapting to Sony (per my experiences when I did adapt them to Sony. As I indicated this has likely changed (improved), so I don’t know the status now.

I really don't see why this won't be the case for RF lenses. What is the point to specifically go through the trouble of getting RF lenses to adapt to sony if you will be missing a major chunk of what that camera can do. I mean the only reason would be for something sony don't have. Like the 50 f1.2. And if you went that way, it would be a shame to place a 2.5k lens like that on a body that essentially cripples the lens.
Just my 2c

-- hide signature --

Nelson

gazza73
OP gazza73 Senior Member • Posts: 1,015
Re: RF lenses on other cameras
1

lawny13 wrote:

What is the point to specifically go through the trouble of getting RF lenses to adapt to sony if you will be missing a major chunk of what that camera can do. I mean the only reason would be for something sony don't have. Like the 50 f1.2. And if you went that way, it would be a shame to place a 2.5k lens like that on a body that essentially cripples the lens.

The main reason for me wanting to adapt RF glass to a Sony is my long term plan to ditch my A7 cameras when Canon release their pro grade mirrorless cameras in 2020/2021.

The Sony A7rII, A7rIII and probably the A7rIV (unless Canon surprise us) have only ever been a stop gap for me and I've continued to buy Canon EF glass and adapt so adapting RF glass would have been my preference if it were possible.

Keyboard shortcuts:
FForum MMy threads