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
Inner regular measure Inner regular measure In mathematics, an inner regular measure is one for which the measure of a set can be approximated from within by compact subsets. Let ("X", "T") be a Hausdorff topological space and let Σ be a σ-algebra on "X" that contains the topology "T" (so that every open set is a measurable set, and Σ is at least as fine as the Borel σ-algebra on "X"). Then a measure "μ" on the measurable space ("X", Σ) is called inner regular if, for every set "A" in Σ, This property is sometimes referred to in words as "approximation