The Mamyia Sekor E / EF 1.4/50mm is best vintage 1.4/50mm lens I'm aware of, including famous lenses such as the Canon nFD 1.4/50, the Minolta Rokkor MC 1.4/50mm and the Zeiss CY Planar 1.4/50mm. At f1.4 (wide open) is is soft, as are all other vintage 1.4/50mm lenses, but resolution across the field is already pretty good. At f2.8 is is as good as all the other lenses at f4 or f4.5, and that's pretty amazing to say the least.

MAMIYA SEKOR E mm 1:                  (7 lenses /6  elements)