dougpeterson
Workshop Member
In the Hasselblad system there is no focal plane shutter available so the eventual failure of the leaf shutter renders the lens unusable until the leaf shutter is repaired.Although i can only speak from a Hasselblad perspective... The only drawback is obviously lens/shutter failure and with a set of lenses you can always bring home some frames (or you just get 2 of everything, i've heard the saying "One is None" which i tend to live by).
In the Phase One system (e.g. using Schneider LS lenses with an XF) in most cases* you can continue to use the lens when, eventually, the leaf shutter fails by using the focal plane shutter instead (i.e. you force the system to ignore the leaf shutter).
In any LS lens I've dealt with the shutter is the most likely failure, followed by the autofocus, followed by the aperture, followed by the electronics. So having a backup shutter (in the form of a focal plane) is a nice failsafe. For IQ3 owners you also get a loaner during any repairs on any lens purchased with the IQ3 kit; won't help you the day of the issue, but limits the downtime to a day as long as you're in a reasonably accessible point on the earth where UPS/FedEx/DHL can find you (e.g. not on Mount Kilimanjaro).
That said "one is none" is a good mentality, as none of the above will save you (the day of) if you drop the lens into a ravine . A great backup lens on the Phase One side would be one of the better older mamiya AF lenses like the Mamiya 80mm or Mamiya 45mm. They are very light, very small, very inexpensive (relative to any new Schneider/Hassy lens) and are reasonably good in quality (read: not as good as a modern super-lens, but much much better than not having a lens at all).
*The exception being if the shutter fails in a closed position or completely disintegrates. Both are, in my experience, less common types of failures.