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
Borel regular measure becomes a full measure (countably additive) if restricted to the Borel sets. Borel regular measure In mathematics, an outer measure "μ" on "n"-dimensional Euclidean space R is called a Borel regular measure if the following two conditions hold: An outer measure satisfying only the first of these two requirements is called a "Borel measure", while an outer measure satisfying only the second requirement (with the Borel set B replaced by a measurable set B) is called a "regular measure". The Lebesgue outer measure on R is an example of a Borel regular measure. It can be proved that a Borel