Not too long ago, 36MP digital sensors were introduced into 35mm cameras. Not too long after that, many photographers (including some well respected ones) proclaimed that these pixel-rich 35mm cameras could produce “medium-format quality” images.
I don’t subscribe to this view, at least when it comes to portrait photography.
If you examine the images I’ve taken with the Mamiya RZ67 (6 x 7 medium format film), you will note that they look more “true to life” as compared to images from 35mm cameras (digital or film). The tonal transitions are subtler, the separation of subject matter from the background is more natural, and the overall rendering is somehow “more grand” than 35mm camera images (like these ones from the Nikon D800E + Zeiss Otus - a supposed “medium-format-quality” producing combination).
Even the Pentax 645D, a camera that possesses a digital sensor that is only a little bit larger than the one in the D800E, somehow produces “grander” images (but not as “grand” or true-to-life as the larger 6 x 7 film “sensor” in the Mamiya RZ67).
As I’ve written before, sensor size matters:
So, if you’re looking for a medium format look (at least with respect to portraiture), you will not get it from a Nikon D800E/D810, or Sony A7R, etc.
If you’re looking for medium format resolution, that’s another story…