Somewhat repeating what Jörgen says;
Hasselblad H system does not cover 6x6. Except for this digital back the Hasselblad V system is already discontinued (and virtually dead in the pro market), and the resolution of the V lenses is not up to what digital MF users has come to expect.
Hy6 is the only digital platform out there for which a 6x6 (=56x56mm effective area on film) seems logical.
I'm also a bit skeptical about how popular a square format would actually be among modern photographers though. If you're going to crop it to rectangular 99% of the time, who wants to pay the extra for a custom 56x56mm sensor when you can get 56x41mm for a much lower price? Some artists surely would like the square format, but for general professional photography where the bulk sales need to be, is square format any good?
Square seemed pretty good for many, many decades.
I commercially used a V for 40 years and frankly it was a delight to work with. You develop an eye for square composition, yet still could crop a rectangle either way without turning the camera or flipping the back or anything. Just shoot and crop … or not. Very nice work flow.
I shot all my wedding stuff as a square, and all the album makers made a square slip in mat. Commercially, the square allowed the Art Director to select the image format at will to fit all the various magazine and collaterial aspect ratios and still allow for bleed or gutter drop.
There is a reason the V was so popular, and why there is still a trillion of them out there. IMO, that's partially why Hasselblad discontinued the V, who would pay for new when there so many working Vs to be had at a fraction of new prices?
As to lenses, yes some may not hold up to excruciating 200% corner examination, but some do … and many others have a character that is still highly desirable. The 40IF is quite good, as is the 100/3.5 and the 180/4 … not to mention some of the APOs. I used some V lenses on 39 and 50 meg H cameras, and they brought a lot to the party on their own. There is a look and feel that is less antiseptic than many modern lenses deliver.
My 2¢
- Marc