Angle of view camera–subject distance to preserve the size of a subject, changing the angle of view can indirectly distort perspective, changing the apparent relative size of the subject and foreground. If the subject image size remains the same, then at any given aperture all lenses, wide angle and long lenses, will give the same depth of field. An example of how lens choice affects angle of view. This table shows the diagonal, horizontal, and vertical angles of view, in degrees, for lenses producing rectilinear images, when used with 36 mm × 24 mm format (that is, 135 film or full-frame 35mm digital
Tridecagon Only the g13 subgroup has no degrees of freedom but can seen as directed edges. The regular tridecagon is used as the shape of the Czech 20 korun coin. A tridecagram is a 13-sided star polygon. There are 5 regular forms given by Schläfli symbols: {13/2}, {13/3}, {13/4}, {13/5}, and {13/6}. Since 13 is prime, none of the tridecagrams are compound figures. The regular tridecagon is the Petrie polygon 12-simplex: Tridecagon In geometry, a tridecagon or triskaidecagon or 13-gon is a thirteen-sided polygon. A "regular tridecagon" is represented by Schläfli symbol {13}. The measure of each internal angle of a