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

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.

Aperture

An opening for the purpose of admitting light.

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.

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.
References in classic literature ?
That was, in fact, a marvellous grimace which was beaming at that moment through the aperture in the rose window.
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.
Here he raised the body and thrust it into the aperture where Bradley saw it drop suddenly from sight.
This last to the dead Wieroo as he stooped and dragged the corpse to the central shaft, where he raised it to the aperture and let it slip into the tube.
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.
Each superintendent took his post by the aperture of the run.
When the oat-spry horse had hedged a little his first spurt of speed Jerry broke the lid of his cab and called down through the aperture in the voice of a cracked megaphone, trying to please:
In the trap-door itself was found a square aperture cut in the wood, apparently with some exceedingly sharp instrument, just behind the bolt which fastened the door on the inner side.
If you stand on its summit and look at these two f-shaped spout-holes, you would take the whole head for an enormous bass-viol, and these spiracles, the apertures in its sounding-board.
19, 2014 /PRNewswire/ -- Dual Aperture International (DAI) announced today the assembly of industry and academic stars to take on the next challenges in digital imaging and camera technologies.
The area ratio calculation in its simplest form is a ratio between the dimension of the aperture opening area and aperture wall surface.