Fitted with an adapter, medium format lenses don’t extend into the camera beyond the lens mount because the FFD for these lenses is greater than 60mm.
The 45-90mm Bronica Zenzanon PE
Aspherical lens sold for $2,058 in 1998. Medium format lenses were designed for professional use.
Medium format lenses were designed to cover a much larger film format, 45x60mm, 60x60mm and 60x70mm. A full frame digital sensor only uses the 24x36mm area in the center of the image circle which is where these lenses are their sharpest. Areas around the edges of the circle will not be as sharp, but your sensor isn’t going to use these areas unless you have a shift adapter on your lens.
A 75mm lens is a normal lens for the 645 format and a 50mm is a wide angle lens. On a full frame sensor digital camera, a 50mm would be normal and a 75mm would be a telephoto.
Medium format lenses were manufactured to high professional standards and work well with digital cameras.