Ultra wide angle lens the difference is only whether distortion is present or not. However, the shorter the focal length, the more difficult it is to implement rectilinear correction. In fisheye lenses, the visual angle is close to or more than 180 degrees in at least one direction. For example, a "diagonal fish eye" would have a viewing angle of at least 180 degrees within the diagonals of the frame. A "circular fisheye" would represent the image in the form of a circle. Rectilinear ultra-wide angle lenses are used in photography and cinematography sometimes to achieve three-dimensional perspective distortion instead of simply two-dimensional barrel
38 Degrees 38 Degrees 38 Degrees is a British not-for-profit political-activism organisation. It describes itself as "progressive" and claims to "campaign for fairness, defend rights, promote peace, preserve the planet and deepen democracy in the UK". In October 2013, it was reported to claim 1.9 million UK members. 38 Degrees takes its name from "the angle at which snowflakes come together to form an avalanche". The organisation launched on 26 May 2009. The 38 Degrees website states: "38 Degrees was founded by a group of activists and funders concerned about the state of our democracy and determined to try something different. Founders