There is no such thing as FX lenses for D700, D3 or D3x! FX is the format of the Nikon camera body. Nikon FX DSLR has an image sensor that is larger than the DX format. So you want to use a Nikkor lens that gives you the full frame.

The Original FX Trilogy

Back in 2007, when Nikon launched the first FX format DSLR – D3, it also rolled out two new lenses, and bundled it with an older lens; many call these 3 lenses the “FX Trilogy”.

• AF-S NIKKOR 14-24mm f/2.8G ED
• AF-S NIKKOR 24-70mm f/2.8G ED
• AF-S VR Zoom-NIKKOR 70-200mm f/2.8G IF-ED

Image Sensor: Nikon FX vs Nikon DX

Those numbers work out to be 131% larger area for FX than DX format. More area to pack more pixels resulting on lesser noise.

When you use a DX lens on a FX camera, the resulting image is smaller than the FX image sensor area and you’ll get a cropped picture with lesser pixels and lower resolution. This wastes much of the capability of the FX cameras.

Use Non-DX Lens on Your D700

All non-DX lenses, older AF or manual focus, will give you full frame image on the FX format DSLR.

In other words, non-DX lenses are FX lenses!

You can really get amazingly good picture with the right lens on the Nikon D700! So you see, you can use your good old Nikkor AF lens on the new D700 to get even better result.