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