Steve Hughes , Jul 18, 2009; 12:08 a.m.
Why didn't you ask the question before you did the deal ? it seems to me you were sold a bill of goods, what exactly about the D300 and D200 did not meet your requirements? You now have traded two perfectly good cameras and lenses for 1 camera and effectively just 1 lens and the gobbleydook you are spouting makes makes no sense buddy .
The D700 has what is known as a full frame sensor that is the size of a 35mm film frame while the D200 and the D300 have a DX sensor the size of an aps film frame which is smaller.
The 18-200 mm lens you have is designed to cover a DX frame it will not cover the full frame so you need to toss it. The Sigma lens you have on a D700 is like putting diesel in a Maserati.
Lastly the guy you bought the camera off is wasted, he should be on Wall Street or better still a lobbyist for the insurance companies.
Good luck Steve