The newer lenses are really pushing the resolution up for the FF Nikons and Sony to the level you are probably getting with the 645Z or at least within 20%. You are probably carrying 2x the weight and a lot more size. Pentax is due for an update, but I wonder if their market is growing or shrinking. I would expect the latter.
I suspect so. But that's my complaint. The 645z is a
great camera by any measure--controls, ergonomics, balance, usability, image processing--all of it. It's better in every usability dimension,
for my requirements, compared to the Hasselblad and Fuji competitors. (The Leica S2, well, that's something else, but it's also four times the price). I have shot many paid gigs using Mamiya, Rollei, Hasselblad, Canon, and Nikon equipment, and the Pentax delivers the whole package.
But don't compare it with full-frame cameras, of which I own two. For one, it does not use an AA filter, so images are sharper at the pixel level if one can avoid moire. And the sensor itself is superb--used by Fuji, Leica, and Hasselblad, and very well implemented by Pentax. The main difference there is color clarity. There's more than a 20% difference by far, despite that the Pentax is now quite long in the tooth in technological terms.
Now, to the lenses. Many of the lenses are old. Many require one to stop them down to f/8 or f/11 to get the most out of them. Guess what? Pros do that anyway, simply because they need the depth of field. I made a group photo at a conference using the 45-85 zoom, and autofocus zoom originally designed for the 645NII that I bought in about 2005. The group included 80 people, and I could read their nametags clearly. I have continued to be astonished by the image quality compared to even the Canon 5Dsr, with its 50MP sensor. The lenses for smaller cameras that deliver the same image quality cost thousands each. Pentax's current lenses are even more expensive, but their older lenses work so well that the difference is marginal. I think that as much as anything earns Pentax great praise, but is probably also part of the commercial problem they are having with the camera--it is not driving lens sales. (I have the new 55/2.8 and 28-45 zoom, both of which are as good as any lenses I've ever used for any camera, bar none. And I have these lenses from the film era: 35, 75, 120 macro, 150/2.8, 200/4, 300/4, 400/5.6, 45-85, and 80-160. All of them can support print sizes in feet with no loss of the illusion of endless detail. Are they as good as a Schneider Symmar or Super Angulon, or a Rodenstock Sironar, on 4x5? It would take very large prints to see the difference. The 28-45 was by far the most expensive of these. I did not pay more than $700 for any of the others, and many I bought for $200 or less. With Fuji, I'd have to adapt these Pentax lenses to have as much versatility in the kit, but the lenses work better with the Pentax camera and it's a better implementation of the sensor anyway.
Pentax made those lenses for pros back in the day, when Asahi was as much an optical powerhouse as anyone. They were not cheap relative to the market when they were new, but they are abundant now.
Also, I'm leery of Fuji--they give up on their product lifecycles sooner than Pentax, orphaning a lot of what people have bought. Pentax has supported the 645 lens mount since 1982. The Fuji lenses for their medium-format digital mirrorless camera are expensive and fit no other camera.
But that can't survive a foolish market enamored with oversized point-n-shoots. What I wish is that markets supported diversity like they once did, instead of
everyone having to jump on the
same bandwagon.
Rick "who chose the Pentax over a Canon 5Dsr after a comparison that favored the Pentax abundantly" Denney