I don't have anything at 50mm, and I'm looking for a faster-than-f2 lens; preferably a f1.4, that I can use with an M42 adapter mount for a Canon 6D. I'll probably be selling the 35/2 IS, as I don't really find myself using it all that much these days, but I want something that is fast enough to be my low-light lens for nighttime wanderings.
Since I have other lenses if I want something sharp, or non-vingnettey, or accurate - I don't really care if the bokeh is all sorts of weird or it has lots of CA wide open.
What would you guys recommend for something that'll work with a 6D? Fujinon (EBC or non-EBC?)? Takumar? Helios?