Canisdirus

I use the Sony A7RIV ... it's an image beast and allows severe cropping with stellar results.
Sony also has the deepest native lens line ... which is a bit ironic.
Nikon ... I dunno...seems like they are stumbling around a bit adapting to mirrorless. They are bleeding red...badly. Cut R&D and jobs...which is necessary. Their native line is small...but growing. You'll still have to live by adapter probably (it's never as good as native glass).

Canon. Canon has been impressive. They have the market share globally and seem keen on keeping it. They have made the switch to mirrorless with aplomb, and have enough native glass right now to go with the bodies. No sign of them slacking back.

I'd say ... Canon and Sony ... perhaps in that order.

User ID

Yup. Making better images is the refuge of those who routinely make mediocre shots.

It requires skilled inspection to detect a better or lesser image, but mediocre shots are obvious to viewers without any special image inspection skills.

BurghByrd Loc: Pittsburgh

Your exising Nikon lenses are not useless; they will mount to the Z6II using the FTZ adapter. The FTZ adapter does not contain glass and re-establishes the distance from the back of the lens mount to the sesor (film) plane so the optical quality will not be degraded. Also, the FTZ adapter provides elctronic conections between the lens and camera body so all exposure, autofocus and aperture control is retained. The one exception is that the body does not have an autofocus drive motor so older autofocus lenses (D series and earlier) would have to be focused manually; I believe that is also true for some budget consumer DSLR bodies as well. In short, with an FTZ adapter (I believe Nikon is currently selling them with the Z6II for ~$50) you can fully use your exisiting G and E series AF-S and AF-P lenses (and equivalent). The new mount offers significant advantages for lens design relative to the F mount and other manufacturers as discussed in "Photography Life" (https://photographylife.com/nikon-z-vs-nikon-f ) and the Mirrorless camera body offers features that cannot be fully provided by an optical viewer; so although late to the game, Nikon has begun to invest in their mirrorless future. Also, Nikon has always been commited to their existing customers who have invested in the Nikon system and retaining functionality in the product line has always been a high prriority for them. There are other options but I would not hesitate to invest in Nikon and would probably be cheaper given your current investment in F mount lenses.

CO

The new Nikon Z lens mount is allowing designers to create better lenses.

(Download)

uhaas2009

I always ask if the salesperson mind if I put my money in the camera I try......😉

olemikey Loc: 6 mile creek, Spacecoast Florida

Respectfully, the D60 was fine in it's day (2008), the first Sony Nex MILC came out in 2010, even using that comparison is skewed improvements/time-wise in favor of the Sony; A7R3 is many generations newer (2017 I think).

CO

It's great that the Olympus is lighter and less expensive but Micro 4/3 sensors don't even come close to the performance of full frame cameras like the Nikon Z7II. The full frame sensors are better in every category. The dynamic range of the Nikon Z7 is almost 2-stops wider than the micro 4/3.

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

You said phones could capture birds in flight and blur backgrounds, I asked you to SHOW ME YOURS.
Where are they, like I said, YOUR A TALKING HEAD, no action, no actual personal photographic proof of your claim, all you have are words, nothing more. Go away.

V2volk Loc: St. Louis area

Definitely, lots of money tied up in those Nikon lens

gvarner Loc: Central Oregon Coast

Picture quality depends on the photographer and the media you use to reveal the image. It’s very subjective. The mechanics are the same, camera to camera. Excellent lenses are the starting point there. Others may disagree with me but that’s how I see it.

larryepage Loc: North Texas area

I don't know if you shoot raw or JPEG. If JPEG, your D810 has picture controls that allow adjustment of saturation and contrast and 4 or 5 other parameters that will allow you to match or exceed the mirrorless cameras.

There is no photographic difference with mirrorless cameras. Only process difference and a lot of psychological difference. There are some things about the process that can provide a big crutch if you don't fully understand photography.

Your D810 is an "apex" camera. It has no meaningful shortcomings, if you gave learned to use it properly. When I bought mine, it was intended to be my final camera and could serve as that for as long as I continue shooting. I have a D850 only because it developed that I needed a second full frame body. I like it a lot, but it really doesn't let me do anything that the D810 can do very well, except for slide/negative copying and focus stacking, neither of which get used very much.

I have looked quite hard at the Z7. It is a nice camera, but not built to the same level as your D810. It contains no magic bullet to "fix" your photography. You say that your money is tight, as is mine. My guess is that once the new wears off of the new camera, you might wish for your D810 and your money back.

SuperflyTNT Loc: Manassas VA

Yes Nikon has a new mount for their mirrorless system. Yes you can use probably use your existing lenses with the FTZ adapter. Canon actually has 4 different mount systems, two of those for different mirrorless systems.

SuperflyTNT Loc: Manassas VA

I call bull. I shoot a Z7 and while the D810 feels more substantial, (because it’s bigger and heavier), the build quality of the Z7 is every bit as good as their DSLR’s.

Delderby Loc: Derby UK

Not bad at $4000 a throw - I suppose you have two. Actually the Sony A7 iii has a higher DR at half the price.

larryepage Loc: North Texas area

Maybe, maybe not. We will see how they hold up over time. I hope you are correct. But the one I used for a time did not convey to be particularly rugged.