A wide-angle zoom designed for DX-format sensors, this 12-24mm lens produces an 18-36mm equivalent focal length range.. Constant f/4 maximum aperture offers consistent performance and light transmission throughout the zoom range.. Three aspherical elements are used to reduce spherical aberrations and distortion in order to realize sharp imagery with accurate rendering.. Two extra-low dispersion elements greatly reduce color fringing and chromatic aberrations in order to produce greater clarity and color accuracy.. A Super Integrated Coating has been applied to individual elements to suppress internal reflections, flare, and ghosting for improved contrast and color accuracy when working in strong lighting conditions.