I just bought a hacked Schneider Retina Xenon 50mm 2.8 in LTM mount and not in M mount. I read some old RFF threads on the Xenar and Xenon lenses, and it seems that the Xenon is a very good lens. With shipping, it cost me less than $170, while a similar lens is selling for over $1300. This is "my lens" shown below. I love one of a kind hacked lenses. Do you by any chance own such a lens on a Retina camera, and could you share here your experience with it. Thanks. I wonder how this lens renders, in comparison with the (old) Elmar 50 2.8. My example is RF coupled, and it is uncoated. From ad : The focusing scale is stamped into the mounting ring. The lens is rangefinder coupled and activates the rangefinder as it is focused. It is uncoated glass.