Can the Hasselblad h3d use zeiss lenses?
Very doubtful. I think that the only lenses that fit that mount are maid by Hasselblad. I think...
What film to use with 50mm cameras?
There is no 50mm camera that I know about. If your camera looks like this one then it uses 35-mm film. Other than that the only Mitsuba equipment I'm familiar with is all digital and doesn't use film.
If money is not a problem, which professional digital slr would you choose, Nikon d2xs or Hasselblad H3d?
The Hasselblad. For the same reason as for film. The larger the latent image you start with, the better the finished image will be because you don't have to enlarge it is much. The Hasselblad takes an image the is approximately 4 time larger than the...