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
Silk Degrees Silk Degrees Silk Degrees is the seventh album by Boz Scaggs, released on Columbia Records in 1976. The album peaked at No. 2 and spent 115 weeks on the "Billboard" 200. It has been certified five times platinum by the RIAA and remains Scaggs's best selling album. "Silk Degrees" spawned four singles. "It's Over", "Lowdown", and "Lido Shuffle" made the Top 40, while "What Can I Say" peaked at No. 42. The album was recorded at Davlen Sound Studios and Hollywood Sound Studios in Los Angeles. Among the accompanying musicians, David Paich, Jeff Porcaro, and David Hungate became members of