Well, I have committed to the Rollei X-Act2 Bellows System at the suggestion of Klaus Schmitt, who has helped me with my lens concerns for years, in particular in the realm of the industrial lenses. I also have that Kenlock (Spiratone) Bellows Systems en route, and the seller tells me the Nikon D810 works just fine on that system. So, I hope I have one system to use and one system to sell, and that I don't fall in love with and keep both of them That would be so like me.