The samyang 12mm f20 ncs cs lens is a manual focus wide angle prime with micro four thirds fit for use with the panasonic and olympus mirrorless cameras its lightweight 245g construction combined with its large f20 aperture makes this lens perfect for a wide range of applications including travel landscape interior architecture and astrophotography the lens uses nanocrystal anti reflective coating that sits on the lens elements surface to ensure better light transmission higher res