The Nikkor 12-24mm F/4 G Aspherical ED IF DX SWM AF-S is an ultra-wide angle zoom lens with constant aperture for Nikon DX format Digital SLR cameras. Designed and built to a high standard of quality, this lens is Nikon's top of the line DX wide angle lens. Being a pro level Nikon lens the optical formulation is excellent and the physical construction is solid. The constant aperture design keeps the amount of light coming through the lens consistent while zooming an especially nice feature when working with strobes.
With a broad variable field of view that widens all the way out to 99 degrees (diagonally), the 12-24mm is capable of taking it all in dramatically. It's one of the best DX lenses available for landscapes, documentary work, and architecture (both inside and outside). When you need a lens for close quarters or want to really force exaggerated perspective it's the perfect choice.
Using the 12-24mm on a DX sensor camera yields a field of view equivalent to that produces by a 18-36mm lens used on an FX format camera. While the 12-24mm is certainly useable on FX cameras (in DX crop mode) the Nikkor 16-35mm F/4 G ED AF-S VR , Nikkor 14-24mm F/2.8 G ED IF AF-S Aspherical , Nikkor 17-35mm F/2.8 D ED IF AF-S Aspherical , or Nikkor 18-35mm F/3.5-4.5 G ED AF-S are typically better choices being able to use more of the available sensor pixels.
The Nikon HB-32 Lens Hood is recommended to minimize flare and loss of contrast from stray light on the front of the lens.