Internal FocusA NIKKOR lens in which only the internal lens group shifts during focusing. These lenses will be designated with the abbreviation IF on the lens barrel. Aspherical – Extra-low Dispersion Glass ElementsAn ED (Extra-low Dispersion) glass element that features the characteristics of an Aspheric glass element for a more compact size lens. Like Aspherical lenses, AS-ED lens elements minimize coma and other types of lens aberrations, even when used at the widest aperture by continuously changing the refractive index from the center of the lens. The AS-ED lens elements are optical glass developed by Nikon to obtain optimum correction of chromatic aberrations. Electromagnetic Diaphragm MechanismAn electromagnetic diaphragm mechanism in the lens barrel provides highly accurate electronic diaphragm or aperture blade control when using auto exposure during continuous shooting. With conventional D/G type lenses, the diaphragm blades are operated by mechanical linkage levers. Silent Stepping Motor (STM) ControlNIKKOR Z lenses use a stepping motor for fast, accurate, smooth, quiet autofocus with reduced wobbling. This quiet drive system makes the lenses ideal for use when shooting video.
