I know there are various teleconverters and extensions rings that allow for the use of FD lenses on EF bodies. However I'm looking for an adapter that lets me use EF lenses on an FD mount. Of course I wont have aperture control etc, but it doesn't matter.

I've never seen any of these adapters, but they shouldn't be impossible to make since the flange focal distance allows the adapter to be 2 mm thick.

Are there any sich adapters?

  • I think the big problem is aperture control, but I'd love to know if such a thing exists. – SailorCire Mar 5 '15 at 15:41
  • @SailorCire As I wrote in the question I don't care about aperture control. It's fine without it. – Hugo Mar 5 '15 at 15:42
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    @Hugo But most potential users of such a device would care about aperture control, and thus there is not enough demand in the marketplace to make it worth producing such a device. – Michael C Mar 5 '15 at 16:53
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    I'm not sure it's an avenue worth pursuing given the availability of cheap used EOS film bodies. I picked an EOS 30 a while back for £30 inc. postage just to have a play with the eye-controlled focus and shoot some film with L-series lenses I could never afford when I was younger. Don't forget, with film cameras it's the lens and film combo that matter most, so as much as I loved my old T90 I can get much more mileage with a basic EOS that takes EF lenses - most importantly, lenses which work with both film and digital... – Darkhausen Mar 5 '15 at 18:29

There's an interesting thread here on Reddit. The best comment is from the owner of fdtoef.com where they say:

The first challenge is how to keep the adapter on the FD body, a lock like the FDn lenses. The FDn is too complicated for that amount of space, so it would need to be the original breech-lock approach.

Assuming that the body FD mounting was solvable the next challenge is the locking pin that the EF lens uses to keep it in place. This is the tough one to solve within that 2mm of space

and then noting the fact I think you're well aware of that fitting new lenses onto old bodies is very much a minority sport. So I think the direct answer to your question is "no such adapters are available".


From the Canon EF lens - rear mount EF to M42 body cameras: https://www.ebay.com/itm/EOS-M42-Macro-Adapter-for-Canon-EF-Lens-to-M42-Screw-Zeiss-Pentax-Mamiya-Camera-/272589915064

And From the rear of above adapter M42 male threads to Canon FD Camera Adapter: https://www.ebay.com/itm/Pixco-Camera-Adapter-For-M42-Screw-Lens-To-Canon-FD-Mount-Zeiss-Pentax-Praktica/273374865798

Full Frame 35mm cameras only, otherwise you are going to get a crop factor. I hope this helps someone out there. Keep in mind you would have to get both of these with autofocus and auto-iris retention to adjust aperture on electronic EF lenses. I hope this helps someone.

  • While the adapters will mechanically make the connection between the EF lens and the FD body, the implicit part of the question is whether or not you can mount the lens on the FD and still retain the ability to focus to inifinity. This is basically just not really possible because the flange focal depth of the EF mount is 44mm, and the FFD of the FD mount is 42mm. You can'y reasonably make an adapter only 2mm thick. If the adapter (or adapter stack, as you're suggesting) is any thicker, you've basically just created the equivalent of a short extension tube. when you move the lens too... – scottbb Feb 6 '19 at 22:30
  • ... far from the camera body, you lose the ability to focus the lens to infinity. – scottbb Feb 6 '19 at 22:30
  • This would work if the ef-m42 adapter had an optical element to correct focus, but I don't see such an adapter for sale. – xiota Feb 6 '19 at 23:47

What you want does not appear to be available and likely isn't possible without an optical element to correct focus.

  • The lens side of the mount has to be deep enough for the tabs on the camera body to fit into. Using the width of the locking ring as a reference, that depth is much greater than 2mm.

  • The camera side of the EF mount needs to be deep enough for the tabs on the lens to fit into.

  • The diameter of the mounts is such that you cannot recess one of them into the other.

The best you can expect to do is to position the tabs of the FD body against the tabs of the EF lens. That puts about 8mm between the flanges of the two mounts. You could probably get it to work if you removed the mounts and created a new custom fitting, but that no longer qualifies as an adapter.

The combination of adapters EOS-M42 + M42-FD, proposed by possumfacekid, would work if there were an EOS-M42 adapter with optical element. However, I could not find one. Perhaps it would be possible to add the optics from an FD-EOS adapter to the franken-adapter.

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