Search results
Results from the WOW.Com Content Network
The angular diameter, angular size, apparent diameter, ... For example, if this circle is 5 cm wide on your monitor, view it from 5.15 m away.
A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol ′, is a unit of angular measurement equal to 1 / 60 of one degree. [1] Since one degree is 1 / 360 of a turn, or complete rotation, one arcminute is 1 / 21 600 of a turn.
Common wide-angle lenses for a full-frame 35 mm camera are 35, 28, 24, 21, 20, 18, and 14 mm, the latter four being ultra-wide. Many of the lenses in this range will produce a more or less rectilinear image at the film plane, though some degree of barrel distortion is not uncommon.
The angular width is also called the beam divergence. Beam diameter is usually used to characterize electromagnetic beams in the optical regime, and occasionally in the microwave regime, that is, cases in which the aperture from which the beam emerges is very large with respect to the wavelength .
Angular field of view is typically specified in degrees, while linear field of view is a ratio of lengths. For example, binoculars with a 5.8 degree (angular) field of view might be advertised as having a (linear) field of view of 102 mm per meter. As long as the FOV is less than about 10 degrees or so, the following approximation formulas ...
An angular mil, which is most used in military applications, has at least three specific variants, ranging from 1 ⁄ 6,400 to 1 ⁄ 6,000. It is approximately equal to one milliradian (c. 1 ⁄ 6,283).
The observers in experiment carried out by Murray and colleagues viewed a flat picture with two discs that subtended the same visual angle and formed retinal images of the same size , but the perceived angular size ′ of one was about 17% larger than for the other, due to differences in the background patterns for the disks. It was shown that ...
Angular resolution describes the ability of any image-forming device such as an optical or radio telescope, a microscope, a camera, or an eye, to distinguish small details of an object, thereby making it a major determinant of image resolution.