The Leica Elmarit-S 30mm f/2.8 ASPH CS Lens is a wide-angle prime lens designed for the Leica S-series medium format digital cameras. It provides a 35mm-equivalent focal length of 24mm, giving a broad perspective that is ideally suited to interior, architecture, and landscape shooting. An f/2.8 maximum aperture is ideal for control over focus position for shallow depth of field imagery and also benefits working in dim lighting conditions with available light. The CS version of this lens incorporates a central shutter within the lens design to benefit working with high-speed flash sync at any shutter speed, up to the maximum of 1/1000 sec.
The optical design of this lens features five elements with anomalous partial dispersion and three low-dispersion fluoride elements to reduce chromatic aberrations. Three high-refractive index and two aspherical elements are also integrated into the construction in order to minimize monochromatic aberrations and improve the overall image sharpness and clarity. The rear-most six elements are moved in order to control focus, maintaining a constant lens length while focusing as closely as 1.6' away.