>>3287318Leica M-mount has a FFD of 27.80 mm, so yeah that'd be super easy. Just fix the lens 22.2mm from the mount face and you are good to go. Keep in mind that you can't focus unless you physically move the camera forwards or backwards. You'd probably want to place it further away so that you can focus on things closer to you. It is pretty easy to experiment with two sliding tubes like in this image. Though this is a 60x185mm lens.
