My personal reasons for doing this modifications isn’t really important. Long story short, I bought the 10-22 when I was using a Canon EOS 20D. I loved the lens, and it was my most used lens by far. Moving up to the Canon EOS 5D Mark II (a full framed camera) I knew I wouldn’t be able to use my 10-22mm EF-S mount – and it was my main concern at the time, but I hoped that my 28-70mm lens would be wide enough on a full frame… well I still missed a really wide lens, and since I don’t have an unlimited budget for photo gear… what to do.
I was under the impression that a lens made for an EF-S mount would never work on a EF mount, be cause the lens wouldn’t cover the hole sensor. However from other articles on the net I learned that this was not entirely true for the 10-22. From about 16mm the entire sensor would be covered on a full frame camera, and the back element of the lens would clear to a EF level from about 12mm.
I have been looking at the Canon 17-40mm L lens for a while, but where told by people owning both the 17-40 and the 10-22, that the 10-22 where a superior lens. I don’t like to start a debate over this statement, for me it was enough that the 10-22 where comparable to the 17-40.
So, how to you turn your prised 10-22mm EF-S lens into a great 16-22mm EF lens? Well as we will see later the result turned out to be a 13-20mm EF lens, where the 13 to 16 mm isn’t really usable, but otherwise a fantastic lens on a full framed camera.
If you’d like to try the same you can take inspiration from the steps below. And of course a disclaimer: If you decide to try this modification you do so at your own risk, I take absolutely no responsibility for the result.

























