Designed for Nikon D-Series digital SLR
Design enables a combination of wider angle-of-view with optical characteristics that are optimized for Nikon digital SLR camera sensors
2x Zoom ratio and variable angle-of-view from 99 degrees at 12mm to 61 degrees at 24mm. Comparable to that of an 18-36mm lens on 35mm size sensor format
Nikon design that produces a smaller image circle (the size of the image that is projected by the lens on to the sensor) enabling smaller lens diameter, and optimal image quality from center-to-edge-to-corner on the image
Exclusive Silent Wave Motor enables ultra-high-speed autofocusing with exceptional accuracy and powerful super-quiet operation
2 Extra-Low Dispersion (ED) glass elements for minimized chromatic aberration
3 Aspherical lens element for low distortion
Internal Focusing (IF) design for smoother focusing and great body balance
M/A mode enables instant switching from autofocus to manual with virtually no time lag even during AF servo operation
Nikon D-type design provides precise distance information for flash and ambient light exposure processes
Rounded diaphragm to make out-of-focus elements appear more natural
DX Nikkor is designed exclusively for use with Nikon Digital SLR models
11.8 close focusing distance throughout zoom range

The AFS 12-24 ushers in the concept of DX lenses, that is, lenses designated purely for the smaller imaging sensor size of the current line of digital Nikon cameras. Nikon has actively marketed the DX concept as being instrumental in getting high quality, ultra-wide angle, photography for digital cameras. The company has (probably correctly) identified the possibility of imaging issues, amongst these chromatic aberrations, which may arise from a larger sensor, and opted (in a true oriental way of inscrutability) to try to solve these outstanding issues by addressing the design of optics, not the imager. Thus, the DX lens concept is born. The first of the DX lenses and probably the most eagerly awaited, is the 12-24 mm f/4 lens. Its nomenclature sports a long string of addtional letters to include ED, IF, G, and AFS, all of these codes signify important design features of the lens. You can read about these in the Nikon pamphlets, or rest assured all play their designated parts in making up a potentially great lens.

The lack of an aperture collar on the lens (G type) is less problematical with this lens, because in practice you cannot use it mounted on earlier cameras which don't have the aperture control on the body itself. This results not because of the impossibility of setting aperture on the lens, but because these cameras employ the full 24 x 36 mm film format. The optics of the DX lens is computed to illuminate only the smaller (approx. 16 x 24 mm) size of the imager sensor of the digital cameras. I have checked the 12-24 DX on my F4 and F5 cameras, and you do get a weird kind of "Discovery Channel look" (with the characteristic darkened corners) to the images with the lens set to anything wider than 16 mm. If you can restrain your settings to the 16-24mm range, the DX lens may play a role on a full-format camera as well.

There is no single existing Nikkor lens against which the 12-24 DX can be judged. The only coming to mind is the AFS 17-35 mm f/2.8 Nikkor, but I see that lens as covering quite different photographic tasks than do the 12-24 DX offering. This newcomer is for the crowd of wide-eyed aficionados, it is emphatically not a general-purpose lens in my world of photography. Other people are of course entitled to the opposite point of view. I tend to use the 12-24 DX as a very flexible 15 or 17 mm lens, whilst my 17-35 Nikkor most often operate within the 24-35 mm range so should be regarded as a versatile 24 or 28 mm for my work. Accordingly, there is room for both items in my already overfilled lens arsenal. Pity on me and good news for the Nikon dealers.