The LEICA D SUMMILUX 25mm/F1.4 lens is a bright, large-diameter F1.4 standard lens. It incorporates an aperture ring and boasts as many as 10 lens elements in 9 groups, including a large-diameter aspherical lens, which assure a superb optical performance and F1.4 brightness, while one super ED (extra-low dispersion) lens and three ED lenses reduce color bleeding to an absolute minimum.