Have worked my way from a Nikon D70s, to a D80, then a D300 and finally a D7100 before jumping into the very deep end and getting a D850, my first and only FX digital. Have had it for almost two years now, lots to learn about it, part of the challenge I accepted. The only downside is the darn weight of the camera; after a while it eventually gets to be more than I want to carry; three full days and nights at Disneyland in June of 2019 convinced me of that. That is when I started considering something between my D7100 and D850; something preferably FX. Have been thinking about a Z6, now a Z6 II; the snag, I have several older Nikkor manual focus primes from film days; they do OK on the D7100; they do even better on the D850. I enjoy putting one of those primes on either body and going photo op hunting for the day and getting creative. Those primes also do pretty well with taking video. Does anyone know whether those old primes might be compatible with a Z body with that FTX adapter? The other snag, would have to get a Z mount lens, so that gets the investment into any Z system into the questionable to doubtful range. Second option is a D780, the main challenge there....PRICE! I am intrigued by its video capabilities as hyped by Nikon; I especially want in camera time lapse, have enjoyed doing some of those with my D850; D7100 cannot do in camera time lapse video. Third option would be a D750, either a very good preowned or new; the price differential between a new D750 and the D780 is significant enough to make me seriously consider a D750 even though it is older technology. I shoot primarily 'scapes, land and sea; rarely do wildlife or people events or sports. Also do low light and some night shooting. My FX lenses are Nikon 24-70 and 70-200; have used both on both the D7100 and D850. At present the 70-200 is on the D7100. Suggestions, please.