Ront53 Loc: Maryland

Can you use a FX lens on a Crop Sensor Camera (D3100). If so, what are the advantages or disadvantages?

joer Loc: Colorado/Illinois

Yes you can.

If the lens does not have a built in focusing motor it won't autofocus on the D3100. Crop cameras with focusing motors do not have this problem, ex: D7100, D7000, D90, etc..

Some lens characteristics actual improve because the sensor sees only the central part of the image circle.

Stef C Loc: Conshohocken (near philly) PA

1. Yes they work

2. Make sure it's AF-S or AF-I with your 3100, see JoeR's explanation for why.

3. Advantages: You won't need to buy new lenses if you upgrade to FX, usually higher quality, usually better builder.

4. Disadvantages: Price, weight.. not much from a photography standpoint though.

amehta Loc: Boston

The only thing to add to joer and Stef C's responses is that zoom ranges are selected in ways that many photographers find useful. The zoom range of a FX lens put on a DX camera, however, might not be as useful. For example, the Nikon "all-in-one" DX lens is 18-300mm or 18-200mm and the FX is 28-300mm. If you get the FX lens, you will not get the 18-28mm range, which is the entire "wide angle" range on a DX camera. It's fine if you then add a 10-24mm lens, but it is no longer "all-in-one".

In general, it can be better using DX lenses for wide angle and ultra wide angle focal lengths, FX lenses for telephoto, and "it depends" for "normal" focal lengths.

BboH Loc: s of 2/21, Ellicott City, MD

Yes. You will get the DX's FOV.
Using a full frame lense on a crop frame camera is no issue; but using a crop frame lens on a full frame camera somewhat restricts the capability of the camera.