number aperture
1Aperture synthesis — or synthesis imaging is a type of interferometry that mixes signals from a collection of telescopes to produce images having the same angular resolution as an instrument the size of the entire collection. At each separation and orientation, the… …
2Aperture masking interferometry — is a form of speckle interferometry, allowing diffraction limited imaging from ground based telescopes. This technique allows ground based telescopes to reach the maximum possible resolution, allowing ground based telescopes with large diameters… …
3Aperture — For other uses, see Aperture (disambiguation). f stops demonstrated on a lens …
4Aperture card — An aperture card is a type of punched card with a cut out window into which a chip of microfilm is mounted. Such a card is used for archiving or for making multiple inexpensive copies of a document for ease of distribution. The card is typically… …
5aperture — (f/number) Lens opening. The opening in a lens system through which light passes.The size of aperture is either fixed or adjustable. Lens openings are usually calibrated in f numbers …
6aperture — /ˈæpətʃə / (say apuhchuh) noun 1. a hole, slit, crack, gap, or other opening. 2. the opening in the diaphragm of an optical instrument which controls the amount of light allowed to enter; in a camera, usually measured as an f number or f stop,… …
7Aperture (botany) — Apertures are very small spots on the walls of a pollen, where the wall is thinner and/or softer. For germination it is necessary that the pollen tube can reach out from the inner of the pollen and transport the chromosomes to the egg deep down… …
8F-number — In optics, the f number (sometimes called focal ratio, f ratio, or relative aperture [Smith, Warren Modern Lens Design 2005 McGraw Hill] ) of an optical system expresses the diameter of the entrance pupil in terms of the focal length of the lens; …
9Numerical aperture — The numerical aperture with respect to a point P depends on the half angle θ of the maximum cone of light that can enter or exit the lens. In optics, the numerical aperture (NA) of an optical system is a dimensionless number that characterizes… …
10f number — /ˈɛf nʌmbə/ (say ef numbuh) noun the ratio of the focal length of a lens system to its effective diameter, used to number aperture openings in a camera. Also, f stop. {f(ocal length) + number} …
