IMO, the Nikon D810 is the best camera I have ever had the opportunity to work with. Period. The reason, aside, from 36 Mpx, is the true ISO 64 and the usability (barely) of Live View. But there are other cameras inching up and they have features of their own.
Currently I am looking at the Nikon D810, the Pentax K1, and the Sony A7rII. For sure, the D810 is easiest for me to use, partially because I am so used to it. However, the reason it’s so used by me is because it’s so damn good for the close-up work I do, and ad infinitum.
For sure, the Pentax K1 is the most difficult to use IF I want to use all of the non-Pentax glass I have collected over the years. Trying to photograph with lenses “adapted” to the K1 is possible, but no real fun, except in the results. The K1 is 36 Mpx.
And the Sony A7rII, perhaps the best mirrorless I have used, is pretty easy to use, as well, and boasts 42 Mpx. What I wanted to know is: If I bend these cameras to one lens, in this case the Zeiss Otus 55mm APO, with a tiny bit of extension (5.8 mm), how do they compare?
And “Yes....” it is hard to compare cameras (for me at least), and the color is not perfect, and the images are different sizes, etc., and so on. Also, what I can show here in .JPG format is nowhere near what I am seeing in the original images on my NEC MultiSynch PA302w monitor. So, this is case of your getting the soup of the soup of the soup – trickle down.
To my old and weary eyes, they all look pretty good and more than usable. Certainly the Pentax K1 punches purity right at you, at least looking at the originals. The A7rII is right there with it, and believe it or not, the Nikon D810, Bayer filter and all, perhaps has less noise of them all.
You can look these over for yourselves. Keep in mind that you are looking at very dumbed-down images, but hopefully something comes through.
Not stacked, high aperture, f/16