No; the larger sensor size of the Mamiya as a medium format camera will give less depth of field for a given aperture than the 35mm Nikon. Otherwise you're rig

No; the larger sensor size of the Mamiya as a medium format camera will give less depth of field for a given aperture than the 35mm Nikon. Otherwise you're right, so in the odd circumstance the poster has a Nikkor 50/1.4 medium format or Mamiya small format 50/6.3 then their depth of field characteristics will be as you said. I'm also pretty sure that even on 6x7 50mm @ f/6.3 wouldn't give DoF characteristics anywhere near 50mm @ f/1.4 on a DX sensor (as the extreme examples to artificially push them closer together), and they'd have a radically different field of view.