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
The Three Degrees following year they released a new single "Holding Back". In January 2011, Freddie Pool replaced Cynthia Garrison, who was suffering from Piriformis syndrome, as the Degrees had touring commitments to fulfill. In 2016 The Three degrees released their first full-length studio album with member Freddie Pool entitled "Strategy: Our Tribute To Philadelphia", through Cherry Red Records. The Holiday/Scott/Garrison version of The Three Degrees was the longest running formation of the group (1989–2010). The Three Degrees The Three Degrees is an American female vocal group, which was originally formed in 1963 in Philadelphia, Pennsylvania. Although a total of 15 women have