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
Angle trisection angles can be trisected. For example, for any constructible angle , an angle of measure can be trivially trisected by ignoring the given angle and directly constructing an angle of measure . There are angles that are not constructible but are trisectible (despite the one-third angle itself being non-constructible). For example, is such an angle: five angles of measure combine to make an angle of measure , which is a full circle plus the desired . For a positive integer , an angle of measure is "trisectible" if and only if does not divide . In contrast, is "constructible" if