Hi Ryan,

For one thing, the D850 is 9 fps vs. 5 fps for the D810. That's huge for shooting steam engines, if you're like me and you think rods-centered shots are just not pleasing to the eye at all. The key thing to note is that to get 9 fps (vs. 7 fps), you need the optional battery grip. That battery grip has the same battery as the D4/D5 cameras and requires a charger that is expensive. If you don't currently own a D4/D5, the grip, battery and charger adds almost $1000 to the cost of the $3300 D850.

The 850 also has a ton more resolution than the 810, IF you need the resolution and WANT the resolution. High res images are nice, because you can crop the heck out of them and still have a decent res image. The bad thing about the D850 is that it now has enough resolution to find flaws in every lens you own. Super zooms like the 28-300 won't produce images as sharp as the 70-200 f/2.8E, which was recently released, specifically for high-res cameras. Those large files might also complicate your on-line and back-up storage plans, unless you are really diligent about screening the take from every shoot and deleting all but the no-kidding keepers.

I personally am torn about the idea of owning an 850. I don't really need 45 MP and while I do have good glass, my technique might not survive 45 MP..... Plus, the camera has one SD slot and one XQD slot. Not sure what kind of sense that makes. At least with the D5, you can order one with two CF slots or two XQD slots, so you only carry one type of memory and the second slot is either a back-up or a roll-over.

Of course, you can't even visit a camera store and play with one at this point. Most Nikon dealers don't even have one to demo for you.

/Kevin Madore