When using a DX lens on an FX camera, the camera should have its settings adjusted for a DX lens. A wide angle DX lens won't work the same on an FX body as an FX wide angle lens works. Wide angle lenses are awesome for landscape--such as doing a beach scene. If you position the camera close to the sand, it yields a VERY wide angle point of view. However, when you do that with a DX lens (even on an FX body), you will miss out on the part of the photo that is really close to the camera. A DX lens on an FX body will still crop the image.... If you are looking for a wide angle lens for your FX camera, you should look at FX lenses to get the best field of view.