Adapter for Sony mirrorless lens to Canon RF body

[jblazar]

Sony just came out with the Sigma 14mm f/1.4 DG DN | Art which has gotten great reviews for astrophotography.  Is there an adapter to allow use of this on a Canon R5?

[AtticusLake]

No.  An E-mount lens needs to be exactly 18mm from the sensor, and L-mount is 20mm; but RF-mount has the lens flange 20mm from the sensor.  So there's no way to get the lens close enough with an adapter in between.  In any case that's an electronic lens, so it wouldn't be compatible with any camera brand it wasn't designed for.

There may be a diopter adapter -- where lenses inside the adapter itself extend the focus distance of the lens -- but all the info I've seen says that these have a terrible effect on image quality.

If you want to know more about lens compatiblity, I wrote an article about it: https://moonblink.info/MudLake/gear/lenses

[jblazar]

Thanks so much for the explanation.  That makes perfect sense.  Sigma says they would like to make an RF version, but Canon won't  (yet) give them permission.

[AtticusLake]

Yeah, we have been waiting for third-party autofocus RF lenses for quite a while.  (There are all-mechanical manual focus lenses.)  I don't exactly know what the deal is, but we're still waiting.

[Waddizzle]

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@AtticusLake wrote:

Yeah, we have been waiting for third-party autofocus RF lenses for quite a while.  (There are all-mechanical manual focus lenses.)  I don't exactly know what the deal is, but we're still waiting.

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If I were in Canon’s position I would want to fill out my lens lineup before I opened up the mount to third party lenses.  The last thing I would want would be for some third party lens become the de facto standard lens for the RF mount.