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
Type 90 Ship-to-Ship Missile Type 90 Ship-to-Ship Missile The Type 90 Ship-to-Ship Missile (90式艦対艦誘導弾, SSM-1B) is a ship-launched anti-ship missile developed by Japan's Mitsubishi Heavy Industries that entered service in 1992. It is a naval version of the truck-launched Type 88 (SSM-1) missile, which in turn was developed from the air-launched Type 80 (ASM-1) missile. The Japan Maritime Self-Defense Force bought 384 of the missiles which it fitted to its "Akizuki", "Takanami", Hayabusa, and "Murasame"-class ships. With a range of , high subsonic speed and warhead, the Type 90 is similar to the US's RGM-84 Harpoon missile, and is replacing Harpoon on Japanese ships.