>Your D90 has a 12Mp DX sensor. > >Using the D800 in DX mode will give about 15.5Mp so slightly >more resolution than D90. However, the high ISO noise is >substantially less and the dynamic range is more...so it will >be a noticeable improvement. > >Using the D600 in DX mode will give about 10Mp, so less >resolution but with same ISO and dynamic range advantages as >D800. the controls and menu system on D600 is an evolution of >the D90 design so you will make the switch more easily but if >you want to routinely use DX lenses then the D800 is a better >choice. > >It really is a bit of a waste to throw all those pixels away >by shooting in DX so either make a commitment to buying some >nice wide FX glass or stay with a DX camera such as D7100 >which gives you 24MP on DX and a decent high ISO noise >advantage over the D90.
With fx I will be covered from 24(24-70)to 300(70-300vr). I plan on shooting 8-16 in dx mode. Also on occasion my 70-300. When i purchased my camera 3 years ago, everyone said go with a D90, get experience and than move up. If I purchased a D700 back then I would already have been set up now. I now have these DX lenses and camera that have depreciated and will lose about $1,100 in selling them. And I do feel that as a photographer I have exceeded the capabilites of my D90. When every is still shooting with their full frame, i am putting my camera away or try to go for black & white conversation. I am extremly fortunate that I can afford it(afer selling my 52 mgtd). At my age 66 might as well go for the best.