I would prefer an old Leitz screwmount glass. In 25 years of research , I could not find a answer about how they engineer these lenses but they are best at low light. You dont even need more than 400 ASA Film and no special chemistry but photographs would turn to you with enormous detail , when you go to skin details , oh my god amazing , what a horrible lots of skin details , vains , lots of tonal dancing on the surface , lots of shadow play , skin draperies , micro detailed surfaces and an amazing tone , bones , bones would turn to visible and amazing life likeness.
Zeiss is more red colored , harsh details and raw details , turns ugly.
For 2012 , there is 1950s technology never made better than it.