Buy Nikon D850 from Amazon | B&H
Nikon D850 High ISO test published at dpreview, As you can see the noise performance of the camera is far better then its predecessor. Not only that Sony A7R II camera noise performance also look inferior compared to the Nikon D850. We also have one Medium format camera on the list Fuji GFX 50S, which is bit better compared Nikon D850.
Also see – Best Lenses for Nikon D850
Why not you test against with some Equvalant CANON DSLR cameras….???