Introduction The construction of the lens has also been improved and refined: if it still counts 13 groups, the number of optical element now reaches 17 (15 on the old model). For this lens, Nikon used its Nano Crystal Coat to reduce or eliminate internal reflections and thus to annihilate parasitic phenomena such as flare or ghosting effects.To build this zoom, Nikon used two ED (Extra-low Dispersion) and three aspherical lens elements aiming at reducing aberrations. While the previous 24-120mm also used two ED lens elements, it had only two aspherical ones and no Nano Crystal