The Zeiss Loxia 21mm F / 2.8 is a wide-angle prime based on the Distagon optical concept for a clear reduction of distortions and consistent equal exposure and edge-to-edge sharpness. The optical design also includes four different partial dispersion elements and an aspherical element to control chromatic aberrations, overall brightness, and color accuracy. A Zeiss T * anti-reflective coating has also been applied to lens elements to minimize flare and ghosting for more contrast. Loxia lenses are different because they feature a manual focus design that is specifically tailored for use with electronic viewfinder. They are also equipped with a manual diaphragm ring that can be de-clicked for silent operation. This makes them particularly suitable for film applications.Â