I had this Canon F1 with great lenses, and Canon does not make a 55mm 1.2 anymore, so I started to look for a FD EOS mount adaptor, but all available make you lose 1 f-stop and infinity focus. So I though to my self, this has to work with the EOS if was a bit closer to the Body, so I tock the attachment ring and the aperture ring and made a EOS mount, the hard part was to find the right distance, but it worked! with this mod you can make any FD into EOS with no losses (but control over aperture), actuly, i dont think you will be able to put together the FD rings back…. very complicated… :)
Update in response to Arthur:
Hi Arthur, I used a mount from a broken 18-55 kit lens, i removed the extra EF-S part from it. than i enlarged the whole to fit the larger back element.
To mod the FD lens you will have to remove the mount ring and the aperture ring and whatever else is hanging(dont mess with the focus system.)
Then lock the aperture wide open, and use a lot!! hot glue to fix it on the mount(good becouse if you mistake you can re-do it), use Black take to make sure there are no light leaks.
And thats it
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