The Samyang 14mm f 2.8 ED AS IF UMC Lens 4/3 Fit is a super wide-angle lens designed to work with both full-frame & APS-C sensor cameras. Its optical construction features 14 elements in 12 groups & combines two ED plus two Aspherical elements (hybrid & standard). All lens elements are Ultra Multi-Coated (UMC) with the highest-quality new-generation antireflective layers. This optical construction as well as state-of-the art materials means that you can take photos of the highest possible quality. UMC stands for Ultra Multi Coated, which indicates that the lens has been covered with multi-layered, anti-reflective coating which minimises reflections & increases image contrast. Thanks to its maximum f/2.8 aperture the lens ensures great low light performance. This lens is a manual focus lens & does not autofocus (AF).