The 28 mm f/2.0 SUMMICRON-M ASPH. is the high-speed addition to the 28 mm f/2.8 ELMARIT-M. Its strengths become especially obvious in poor lighting, such as at dusk or in poorly lit interiors where the lens aperture has to be opened as wide as possible to take an atmospheric free-hand shot without using a flash. In order to retain the out-standing performance of the 28 mm f/2.8 ELMARIT-M even at higher speed, the constructive effort for the 28 mm f/2.0 SUMMI-CRON-M ASPH. had to be increased considerably. Thanks to a sophisticated optical formula, in which special types of glass and an aspherical surface were used, the Leica designers succeeded in surpassing the excellent performance of the 28 mm f/2.0 ELMARIT-M. And, although the 28 mm f/2.0 SUMMICRON-M ASPH. is one f-stop faster than the 28 mm f/2.8 ELMARIT-M, the dimensions and the weight are almost identical.