Co-developed with Schneider-Kreuznach, the optical design combines three HR, two ED and three aspherical elements with Samyangs UMC coating to control aberrations and maintain sharp contrast and colors throughout the frame. A 9-blade diaphragm produces pleasing, rounded bokeh. For both stills and video, a linear STM unit ensures fast, quiet autofocus with reliable subject tracking, and an AF/MF switch provides quick access to fine manual adjustment when needed.