• 11 lenses in 10 groups including 2 ED lenses and 2 high refractive index lenses can effectively reduce color difference • The maximum aperture of 1.4 and 9-blade aperture provides natural, smooth bokeh and sharp resolution in low light conditions. With the minimum focusing distance of 0.3m, close-up is very flexible • Adopts STM stepping motor for eye focus, high-speed, accurate, and quiet autofocus • The bottom of the lens is equipped with a micro USB interface, which is convenient for future firmware upgrades and enhances performance • Turn the aperture knob on the bottom of the lens to adjust the aperture automatically, or directly rotate the aperture ring at the bottom of the lens to adjust the aperture