aperture


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Related to aperture: Shutter speed

aperture

Physics
a. a usually circular and often variable opening in an optical instrument or device that controls the quantity of radiation entering or leaving it
b. the diameter of such an opening
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

aperture

The diameter of the unobscured portion of the objective lens in a refracting telescope or of the primary mirror in a reflector. In a radio telescope it is the physical size of the antenna. As the aperture is increased, the telescope gathers more light, radio waves, etc., and thus will discern fainter objects: the radiation-gathering power depends on area, i.e. on the square of the aperture. A larger aperture also produces a smaller Airy disk and so has greater spatial resolution.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006

Aperture

An opening for the purpose of admitting light.
Illustrated Dictionary of Architecture Copyright © 2012, 2002, 1998 by The McGraw-Hill Companies, Inc. All rights reserved

aperture

[′ap·ə‚chər]
(electronics)
An opening through which electrons, light, radio waves, or other radiation can pass.
(graphic arts)
A rectangular cutout on an aperture card.
(optics)
The diameter of the objective of a telescope or other optical instrument, usually expressed in inches, but sometimes as the angle between lines from the principal focus to opposite ends of a diameter of the objective.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

aperture

(1) An orifice. It often refers to an opening in which light is allowed to pass in optical systems such as cameras and lasers. See f-stop and numerical aperture.

(2) (Aperture) A photo editing and management application for the Mac from Apple. Introduced in 2005 and used by professional photographers, Aperture provides sophisticated touch-up tools and works with the iPhoto library. See iLife.
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References in classic literature ?
For a moment they breathed more freely, but presently they discovered that the aperture was continuing to enlarge.
Above him was an arched roof and on either hand walls pierced at intervals by apertures covered with wooden doors.
At more or less regular stages it was pierced by apertures closed by doors, none of which he could open until he had climbed fully fifty feet from the river level.
Sometimes they wore necklaces of small carnation flowers, strung like rubies upon a fibre of tappa, or displayed in their ears a single white bud, the stem thrust backward through the aperture, and showing in front the delicate petals folded together in a beautiful sphere, and looking like a drop of the purest pearl.
Thrust forward through the large apertures in his ears were two small and finely-shaped sperm whale teeth, presenting their cavities in front, stuffed with freshly-plucked leaves, and curiously wrought at the other end into strange little images and devices.
Our fire was just within the cave, the smoke rising through the apertures between the rocks that I had piled in such a way that they arched inward toward the cliff at the top.
Coming to optics, the Galaxy Note10 sports a triple rear camera setup with a 12MP Dual Pixel primary camera with variable aperture ranging between f/1.5 and f/2.4.
In part one of this series, we covered how to choose the best peep sight aperture size for your applications.
With active cooling, the 2400B-405 model can emit greater than 20W from a 7.5mm diameter clear aperture with a 0.66 numerical aperture (NA).
Selection of stencil thickness is traditionally based on maintaining a suitable area ratio (aperture open area divided by wall area) for the smallest aperture size in the design.
Aperture sights on Scheutzen rifles by Stevens, Ballard, Maynard and others helped them drill tight 200-yard clusters.