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
Less than Perfect ABC ceased broadcasting the show, with the last episode broadcast on June 6, 2006. However, those episodes which were not broadcast in the US have been shown in other countries. The show joined Lifetime Television's lineup on June 1, 2009 in syndication. The network aired all 81 episodes, including the eight Season 4 episodes previously not broadcast in the US. But as of 2010, it was no longer on Lifetime's schedule. As of April 2012, Less Than Perfect is part of the lineup of new Canadian network ABC Spark. "Less Than Perfect" was seen on ATV in Austria, on Nelonen