I would recommend the Phase One AF / Mamiya 645 AFDIII solution vs the Hasselblad for lens choices and shutter speed since you are planning to do landscape work.
With the PhaseOne/Mamiya body you have access to not only the new PhaseOne/Mamiya D lenses but a plethora of legacy glass.
I actually just did a quick ebay search and did a search on Mamiya 645 Lenses and came up with over 120 items.
Keep in mind that the Hasselblad H lenses are all Leaf Shutter designs with a max shutter speed of 1/800 vs the Mamiya system employs a Focal Plane Shutter which has a max shutter speed of 1/4000. This can make a big difference when shooting landscapes in a sunny environment when you do not wish to use ND filters.
Also if you need to replace the shutter in the Hasselblad lens it will set you back about $700+.
Both systems can utilize legacy V-series lenses . The H adapter is more expensive than the Phase/Mamiya adapter.
Yes I work for a Phase One / Mamiya reseller, but we offer used solutions of all platforms. I routinely sell used H solutions when we have them available and they are fine systems, but finding used ones in good condition are becoming more of an issue.
You cannot go wrong with either solution, but you will have a greater lens selection on the Phase One / Mamiya platform, it's a fact.
Hope this helps.
You missed the fact that Hasselblad has a HTS 1.5 unit that basically brings tilt and shift capabilities to the 28, 35, 50, 80, 100 primes on the H system, with full tilt, shift and rotation readouts in the H body. The max shutter speed of 1/800 was a consideration working against the H system when I was considering my purchase between the H and the Phase One system, and I had purchased the H over the PO for two reasons - True Focus (which works) and better ergonomics (subjective, but I prefer the H over the PO for this)
The fact that there are hundreds, if not thousands, of Hasselblad H shooters around the world producing work for editorial, billboards, fine art and other fields indicates that the difference in lens performance (as you claim) does not play as large a part as some people would like us to believe.
On the topic of legacy glass, some points worth noting, something I noted from observation and discussion with peers and friends who shoot both systems - having legacy (read: cheap) glass as an option is great. Yet time and time, there are discussions about 'how much better' the new lenses are. Most people I know end up either buying the legacy glass and eventually move on to the D or LS lenses, leaving them to either shelve the legacy glass or go through the hassle of selling it off, and this is especially so when they move up to better sensors and are led to believe that the old glass just isn't as good.
if anything, here are the facts that I had considered between the H and PO systems:
- Phase One, with the right digital back and strobes, will allow you to shoot at 1/1600s on the leaf shutter. Hasselblad is limited to 1/800s
- Phase One will give you 1/4000s shutter speeds, while Hasselblad is limited to 1/800.
- Phase One requires a separate battery pack for the body (6 AA batteries) and back, as opposed to Hasselblad's one-battery solution that powers the back AND the body.
- Phase One lacks True Focus, something I have found useful when shooting portraits and macro. Not a killer feature for most, but I have found it useful
- Hasselblad has the HTS accessory - adds 1.5x teleconversion, x1.3 to aperture, tilt/shift/rotation to the primes. Useful for landscapes and architecture, portraits and product shots. I have not seen such an accessory for PO systems. I am, however, aware of a 50mm shift (no tilt) lens for the PO, a 'legacy' design, as Lance would put it.
- The H4D-40, at ISO1600, shoots remarkably clean. I don't use it all the time, but it's nice to know that it's there when I need it.
- The H4D-40 can shoot long exposures to 256s. The P45+ can go to 1 hour, but I'm told it needs another hour to shoot a black slide. The Hasselblad does not require a black slide, i just shoot the next frame as soon as my current one is done.
I've basically kept my selection simple - I buy a lens that works with the back and stick with it. Clearly others before me have been able to create amazing work from either system, so I'm not thoroughly convinced that the system is the limiting factor at the moment. With Hasselblad, my lens selections are simple where focal length is concerned. The only decisions to make are whether to go for the ver 2 of the 50 and 120 lenses, and I am told the 50-II is much sharper in the corners as opposed to the original 50. Ditto for the 120, but the price premium isn't something I am bothered to pay for at this point in time (the 50-II sells in the used market for $4k, while the original 50 sells for slightly over half that; likewise, the 120-II is around $1.5k more in the used market as compared to its predecessor).
While I respect the PO system, I went for the H system in the end not because it was technically better or worse, but it simply felt better to work with, all things considered. Again, I stress that considering how many professionals around the world shoot with either system, you can't go wrong with either of these.