This lens is quite an old and particular lens, designed in the
'80s for 6x7 cm film. I've tested on a full frame Canon 5D using a
mechanical converter from Pentax 67 to 42x1 and then a ring from 42x1 to
EOS. Vignetting is very good, as expected being this lens designed for
medium format cameras. Unfortunately the optical quality at full
aperture is not perfect, showing noticeable chromatic aberration. It
should be stopped down at f/4 or f/4.8 to get best results. Star sizes
are not pinpoints, but this is normal being the lens designed for medium
format film.
Click on the image to get a full res version
Click on the image to get a full res version