The D850 and 1DX are very different in size and weight.
I find the D850 to have a very manageable size and never found the a7/a9 confortable.
I love the idea of being able to only carry an a7 sized device but I dislike the experience the moment I start photographying with it.
Cheers,
Bernard
I hope Nikon has taken a good look at the Leica SL. The competitive target may be Sony, but there might be more to learn from Leica.
I think a lot of the problems I have with Sony a7 ergonomics stem from the fact that it's just doing too much all the time. I mean there are 107 different autofocus modes and 84 different autoexposure modes, and picture styles for all your Instagram needs, and on and on. There are buttons scattered all over the tiny body that I've never been able to train my fingers to find quickly, and the viewfinder has so many icons to show me all the things its doing that I can forget to look at the subject in front of me.
I've owned two of the Sonys at a time for three years now, and that's still all true for me. I took advantage of Leica's "Test -drive and SL" promotion and found myself comfortable with the fout (unlabeled) buttons in a weekend. And that dedicated button that changes the viewfinder from the EVF to the screen? Pure genius.
I hope Nikon, who has the heritage of great rangefinder cameras and the F3, as well as the D5 and D850, develops a mirrorless that gets out of the way and lets me take pictures. Leica's idea of programmable buttons in places easily found by your fingers is a good one. A button dedicated to the viewfinder is brilliant. A quiet shutter (like a rangefinder), in additon to silent, is a good thing.
Lenses have to be great. They just do. But do they have to be f/1.4? or would a great f/1.8 lens that was smaller work? Autofocus lenses and fast lenses seem to have to be big. Manual lenses can be smaller. Is that OK? I'm not sure. I've been eyeing the Loxia lenses for my Sony. But I've also been looking hard at the Leica SL, because the lenses are great, and I still can't get in love with the Sony.
I would buy the Nikon mirrorless as an addition to my Nikon DSLR, not to replace it. It's going to occupy a different niche (or at least I hope it does). I don't see it replacing the D850 any more than the D850 replaces the D5. Sure, vor some people, the D850 is good enough for sports, but if that's your livelihood, the D5 is your camera.
I really hope Nikon has as clear an idea behind this camera as they do the D5. If they do, it'll be brilliant.