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
Simca Type 180 Renault/Peugeot Douvrin engine, but the displacement of the Simca 180 2.2-litre was slightly less. Later, this engine was also turbocharged, for use in the Citroën BX4TC and Peugeot 505 Turbos as the block was stronger than the Peugeot engine. Applications: Simca Type 180 The Type 180 is an automobile straight-4 engine produced in the 1970s. It was an OHC design. These engines (1,639/1,812 cc) were used in the Chrysler 160/180, a car also sold under a multiplicity of other names. Applications: The 1,981 cc Type 180 was most common. It was used in various Chrysler Europe and Simca models. Applications: