The AF-S NIKKOR 20mm f/1.8G ED from Nikon blends a desirable broad field of view with a sleek form factor, a bright design, and a sophisticated optical layout. The fast f/1.8 maximum aperture excels in difficult lighting conditions and also offers increased control over the depth of field. The optical design incorporates both aspherical and extra-low dispersion elements to minimize spherical and chromatic aberrations for greater sharpness and clarity. Also, both Nano Crystal and Super Integrated Coatings have been applied to reduce flare and ghosting for improved contrast and color accuracy.  Ultra wide-angle prime is designed for FX-format Nikon F-mount cameras, however, it can also be used with DX models where it provides a 30mm equivalent focal length. Two extra-low dispersion glass elements are used in the optical construction to reduce a variety of chromatic aberrations and color fringing for a high degree of clarity and color neutrality. Nano Crystal and Super Integrated coatings have been applied to lens elements to minimize surface and internal reflections for a marked reduction in lens flare and ghosting. A rear focusing design is also used, where only the rear lens group is moved during focusing, to maintain the overall length of the lens during use and to promote faster focusing speeds.