Nikon PC-E FX NIKKOR 24mm f/3.5D ED Fixed Zoom Lens for Nikon DSLR Cameras Three ED (extra-low dispersion) glass elements offer superior sharpness and color correction by effectively minimizing chromatic aberration. Three aspherical elements virtually eliminate coma and other types of lens aberration even at the widest aperture. The Nano Crystal Coat virtually eliminates internal Reflections across a wide range of wavelengths for even greater image clarity High-performance super integrated coating (SIC) offers superior color performance and substantially reduced ghosting and flare. Rounded 9-blade diaphragm for more natural appearance of out-of-focus image elements.