"The Rokinon 8mm f/2.8 UMC Series II Fish-Eye Silver Lens for Fujinon X is a high quality ultra wide angle lens designed exclusively for compact system cameras. It gives an immense field of view - 180 degrees, with a 12mm (35mm equivalent) field of view. The 8mm is a diagonal fisheye lens for APS-C format, meaning that the image it produces fills the frame on APS-C cameras. As with all current Rokinon lenses it is manual focus only. It is also compact, and lightweight, giving a perfect combination with compact system cameras. The optical construction of the lens is 10 lens elements, 8 groups, 1 ASP and 2 ED elements for optimum optical performance. The aperture consists of six diaphragm blades with apertures available from f/2.8 to f/22. It has an Internal focusing (IF) system which means the lens does not change in size when focusing. Additionally, the Rokinon 8mm fisheye features the latest generation multilayer anti-reflection ultra multi-coating (UMC) to minimize flare and ghosting. The integrated lens hood also helps to reduce flare from behind the lens. Due to the very large depth of field produced by such a small focal length lens, focus can be easily achieved by simply setting the approximate distance on the lens scale. Setting the lens to around 1m at f8 will produce images that are sharp from very close objects to infinity. As with all manual focus lenses for critical or in very close focus situations you can use Live-V ie|180 degrees, with a 12mm (35mm equivalent) field of view.|10 lens elements, 8 groups, 1 ASP and 2 ED elements for optimum optical performance.|Internal focusing (IF) system which means the lens does not change in size when focusing|Multilayer anti-reflection ultra multi-coating (UMC) to minimise flare and ghosting.|Integrated lens hood also helps to reduce flare from behind the lens."