It's impossible to get the shallow DOF on 35mm that I can get with the Contax 645 at f/2 and still retain a really sharp image.
Think about what you're saying here. The Contax normal lens is 80mm? At f/2 that's a 40mm aperture. If you use a 50mm lens at f/1.2 you have the same depth of field, because that's also a 40mm aperture. Exactly.
"Often moments come looking for us". - Robert Frank
"Make good art!" - Neil Gaiman
"...the heart and mind are the true lens of the camera". - Yousuf Karsh