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
Six Degrees of Separation (play) Six Degrees of Separation (play) Six Degrees of Separation is a play written by American playwright John Guare that premiered in 1990. The play was nominated for the Pulitzer Prize for Drama and was nominated for the Tony Award for Best Play. The play explores the existential premise that everyone in the world is connected to everyone else in the world by a chain of no more than six acquaintances, thus, "six degrees of separation". A young black man named Paul shows up at the home of art dealer Flan Kittredge and his wife Louisa, known simply as "Ouisa", who