he AF-S NIKKOR 24-70mm f/2.8G ED delivers fast, wide-angle to medium telephoto zoom capabilty and is optimized for edge-to-edge sharpness on both Nikon FX and DX format D-SLRs. Its fast, fixed f/2.8 aperture enables exceptional low-light performance and consistent exposure across the entire zoom range.
The AF-S DX Zoom-NIKKOR 17–55mm f/2.8D IF-ED’s ultra-fast, f/2.8 fixed aperture ensures stunning clarity, beautiful background blur (bokeh) and consistent exposure across its entire zoom range and opens the possibility of shooting in a wider variety of lighting scenarios—without a flash.
Its DX-optimized design makes for a smaller, lighter lens that achieves optimal quality from center-to edge-to-corner of the image. Depending on which camera is being used and its sensor size, depends on which lens would be prefer.
The DX sensor makes possible the production of lighter, smaller cameras, but because it covers a smaller portion of the image projected by the lens, a 1.5x crop factor (so called because the smaller sensor crops the image compared to an image from a 35mm film frame) is introduced. This means, for example, a 24mm lens on a DX sensor camera will provide an approximate 36mm view.