Aperturenoun
An opening, gap, or hole, usually small and narrow
Aperturenoun
(optics) Something which restricts the diameter of the light path through one plane in an optical system.
Aperturenoun
The diameter of the aperture (in the sense above) which restricts the width of the light path through the whole system. For a telescope, this is the diameter of the objective lens.
Aperturenoun
The (typically) large-diameter antenna used for receiving and transmitting radio frequency energy containing the data used in communication satellites, especially in the geostationary belt. For a comsat, this is typically a large reflective dish antenna; sometimes called an array.
Aperturenoun
The maximum angle between the two generatrices.
Aperturenoun
The act of opening.
Aperturenoun
An opening; an open space; a gap, cleft, or chasm; a passage perforated; a hole; as, an aperture in a wall.
Aperturenoun
The diameter of the exposed part of the object glass of a telescope or other optical instrument; as, a telescope of four-inch aperture.
Aperturenoun
a device that controls amount of light admitted
Aperturenoun
a natural opening in something
Aperturenoun
an man-made opening; usually small
Aperture
In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane.
Irisnoun
(botany) A plant of the genus Iris, common in the northern hemisphere, and generally having attractive blooms (See Iris (plant)).
Irisnoun
(anatomy) The contractile membrane perforated by the pupil, which adjusts to control the amount of light reaching the retina, and which forms the colored portion of the eye (See Iris (anatomy)).
Irisnoun
A diaphragm used to regulate the size of a hole, especially as a way of controlling the amount of light reaching a lens.
Irisnoun
(poetic) A rainbow, or other colourful refraction of light.
Irisnoun
(electronics) A constricted opening in the path inside a waveguide, used to form a resonator.
Irisnoun
(zoology) The inner circle of an oscillated color spot.
Irisverb
To open or close in the manner of an iris.
Irisnoun
The goddess of the rainbow, and swift-footed messenger of the gods.
Irisnoun
The rainbow.
Irisnoun
An appearance resembling the rainbow; a prismatic play of colors.
Irisnoun
The contractile membrane perforated by the pupil, and forming the colored portion of the eye. See Eye.
Irisnoun
A genus of plants having showy flowers and bulbous or tuberous roots, of which the flower-de-luce (fleur-de-lis), orris, and other species of flag are examples. See Illust. of Flower-de-luce.
Irisnoun
See Fleur-de-lis, 2.
Irisnoun
the inner circle of an oscillated color spot.
Irisnoun
same as iris diaphragm.
Irisnoun
plants with sword-shaped leaves and erect stalks bearing bright-colored flowers composed of three petals and three drooping sepals
Irisnoun
muscular diaphragm that controls the size of the pupil; it forms the colored portion of the eye
Irisnoun
diaphragm consisting of thin overlapping plates that can be adjusted to change the diameter of a central opening