 | 1977 - 614 lapas
...aperture or diaphragm of the lens). Specifically, the amount of light reaching the film is determined by the ratio of the focal length to the diameter of the aperture. This ratio is called the relative aperture of the lens. The amount of light reaching the film will... | |
 | Arthur Lovat Higgins - 1926 - 166 lapas
...while the time of exposure will be as the inverse of this, or f -^ The sizes of stops are specified by the ratio of the focal length to the diameter of the aperture, such as //32, or by numbers in the same ratio as the areas of the aperture, Stop f/82 being Number... | |
 | Society of Motion Picture and Television Engineers - 1921 - 404 lapas
...the ratio = — (theoretical),- while the DO abscissae values are in terms of the stop number, that is, the ratio of the focal length to the diameter of the limiting diaphragm. The orflinate values apply to the left hand segment of the curve while for the... | |
 | Berthold Horn - 1986 - 530 lapas
...side of the compound lens will be focused at a distance /2 on the other side. 2-7 The /-number of a lens is the ratio of the focal length to the diameter of the lens. The f-number of a given lens (of fixed focal length) can be increased by introducing an aperture... | |
 | J.K. Petersen - 2002 - 1088 lapas
...generally associated with higher F numbers up to the maximum luminance available. For lenses, the F number is the ratio of the focal length to the diameter of the aperture. On camera lenses, the F number associated with the maximum aperture is often inscribed on the lens... | |
 | M. Henini, M Razeghi - 2002 - 536 lapas
...negligible1. The photon flux density incident on the detector focal plane arrays is (231 where //# is the ratio of the focal length to the diameter of the limiting aperture or lens. Under these conditions the background-induced photocurrent in any photon... | |
 | H. V. Nema, Nitin Nema - 2003 - 300 lapas
...frequency of ultrasound; d is the diameter of the focussed transducer; .. is the wave length and f number is the ratio of the focal length to the diameter of the transducer. Hence by increasing the frequency in equation 1, microscopic resolution is obtained over... | |
 | Osvaldo Gervasi - 2007 - 1208 lapas
...that will enter the optical system. We denote the aperture diameter by a^am. The f/stop (or F number) is the ratio of the focal length to the diameter of the aperture of the lens, -^— . Note that the aperture diameter is not completely specified by the f/stop. Indeed,... | |
 | Arthur Lovat Higgins - 1926 - 168 lapas
...//\2 time of exposure will be as the inverse of this, or I ^ . \a/ The sizes of stops are specified by the ratio of the focal length to the diameter of the aperture, such as //32, or by numbers in the same ratio as the areas of the aperture, Stop f/32 being Number... | |
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The relative aperture or /-number of a photographic lens is the ratio of the focal length to the diameter of the entrance pupil. 