Ultra-wide picture angle of 180 degrees on DX sensor is achieved by producing a smaller image circle (the size of the image that is projected by the lens onto the sensor) enabling a smaller lens diameter, lighter weight and optimal image quality from center-to-edge-to-corner on the image.
Nikon 24-70mm f/2.8G ED AF-S. It has been totally worth it so far. I would recommend this lens to any full-frame Nikon user. The widest angle (24mm) is plenty wide for gorgous landscapes and the 70mm zoom is just enough to get a nice portrait
Nikon AF-S DX 10-24mm f/3.5-4.5G ED with its ultra wide-angle perspective and superior image quality, gives users of Nikon DX-format including the D300, D90, D60, D40 and the new D5000 - more opportunities for creative photographic expression