A few possible ingredients, beyond the very substantial increase in sensor cost:
- ...and so a deeper, heavier, slower moving mirror with even more mirror slap to deal with.
- ...so a complete new set of lenses in place of current 645 lens systems.
My comments were inclusive of these realities. (And any 66 lenses brought to market could be used to extend the choices available for smaller formats.)
In 2002 Hasselblad introduced the H1 and with it moved their focus from 66/645 systems to 645/smaller systems. This focus seems to have been a good match with the state of the image sensor market, but I wonder what the 2010s and beyond will bring. I project that the technical dynamics will grow in resemblance to those we had previously in the film only environment, and in this environment I think that 66 cameras have a great strength. 35mm image sensors, and the cameras built around them, are very good, so good that, for me, the 645 cameras currently shipping or announced, aren't enough.
I wouldn't ever ask for a square sensor but I guess the point is people are tired of rotating cameras and waist level finders would work for vertical/square pics (since you wouldn't need to turn the camera). Instead of a square sensor a 6x7 sensor for the RZ67 would be really nice (including the rotating mount).
...Seems like architecture, landscape, product, etc shooters will be the remaining MFDB user base at some point. All served very well with live-view when using tilt-shift.
I understand 6x7 shooters wishing for a 6x7 image sensor. I reason against this because I think it pushes technical considerations out of balance. For example, unless it's designed as a 7x7 camera it won't gain the ability to shoot vertical without rotating the camera, and if it is designed as a 7x7 SLR camera it will be extra large, heavy, and slow--possibly too large, heavy, and slow. I think that a 66 camera is a better technical balance; filling notable shortfalls of 35mm SLR design trade-offs, without creating too many of its own. I suppose that a 6x7 solution would be delightful for tilt-shift work, and architecture, landscape, product etc. categories, but insufficiently strong to outweigh smaller format strengths (at this point in time and at least for the nearer future), and hence would only extend this trend instead of reversing it; but I hope you receive your wish.
Indeed: making the square format cameras that some ask for is probably not done because it has little prospect of being profitable ... ask F&H, Rollei, Leaf, Sinar and Jenoptik. Camera makers are not charities serving poor suffering MF photographers, so addressing the profit motive is unavoidable.
I don't think this is a strong point; none of these companies were offering an "effective" or a "competitive in the broad market" square format digital solution. Note that with the H series Hasselblad moved away from their earlier flagship design of a focal plane shutter camera that also accepted leaf shutter lenses, to a leaf shutter lens only camera, but Mamiya/Phase and Leica are using this design; product or technology successes or failures follow complex factors. As for "profit motives", this is inclusive to my point; insufficient product differentiation and unique strengths are the foundation of the trend away from square and medium formats and the resulting decrease in profits for some companies, and I hope for a reversal of this trend.
Yes: likewise, formats larger than 645 are less and less needed as sensors improve: historically technological progress usually drives format size choices down rather than up. (Getting sensor sizes up to match existing 35mm and 645 AF lens systems is the main recent exception.)
I think the image sensor market is too young to place so much weight on this trend, and there are advantages to larger sensors beyond a potential increase in the number of pixels. More pixels are often welcome, "more effective pixels" are guardedly always welcome, but a better camera is my salient theme and hope; I'm asking for a highly capable camera to shoot square and vertical rectangle format images, without lens factors or the need to be rotated; and a 66 SLR camera seems to be the most effective path, the best fit, within my view of the current and near future, technical considerations and market conditions. Other, or less capable, and smaller format cameras, which offer square format and vertical rectangle optimization, would also be welcome.