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Videology Industrial-Grade Cameras - NEW 2MP Camera 2024 MR

122 terms

Definitions: B

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backreflection -> narcissus

A defect in infrared systems that appears as a dark circular area on a displayed image, caused by radiation reflecting into a detector. It can be reduced by low-reflective coatings or by altering the...

back-illuminated CCD

A CCD that has been reduced in thickness by etching so that light passes through the back layers of the CCD. This type of CCD typically has higher sensitivity, especially to blue light, and higher...

background luminance

The intensity of the light in the scene behind an object being viewed.

band-elimination filter

A filter that suppresses a given range of frequencies, transmitting only those above and below that band. Also called bandstop filter.

barium titanate

A crystalline material used in piezoelectric devices.

beaconage

A system of beacons used in navigation.

bidirectional reflectance distribution function

Unified notation for specification of reflectance in terms of both incident- and reflected-beam geometry; i.e., the ratio of reflected radiance in direction toward the viewer to the irradiance in...

binary digit -> bit

binary digit

binary image

A digitized image consisting of just two brightness levels, as black and white, represented in memory as zeros and ones.

binary on-off

Signal used in optical transmission systems to generate currents in a detector that are decoded with reference to a specified threshold.

binary optics

Optical elements, often created by micromachining, lithography or vacuum deposition, that rely on diffraction of the collected energy as opposed to the more common refracting or reflecting optics....

binary phase-only filtering -> phase-only filter

A type of matched filter that responds only to the phase of incoming light; the output has a much greater intensity than that of a classical matched filter, which responds to phase and amplitude. The...

binary thresholding

An imaging technique that labels all gray pixels as either black or white before processing begins.

biplanar image tube

Also called proximity focus image intensifier. A compact image intensifier that utilizes a microchannel plate intensification stage. This is an in-line device that does not invert the image.

biplanar lens

Electron lens consisting of an homogeneous axial electric field.

Bragg method of crystal analysis

A technique in which a beam of x-rays is directed against a crystal, the atoms of which, because of their lattice arrangement, reflect the ray in the same way as a series of plane surfaces. If the...

bright-field illumination

The illumination generally used in microscopy, whereby the specimen appears dark against a light background.

balsam -> Canada balsam

A resin obtained from the balsam fir, Abies balsamea, used as a lens cement.

bandstop filter -> band-elimination filter

A filter that suppresses a given range of frequencies, transmitting only those above and below that band. Also called bandstop filter.

brightness -> luminance

Luminous flux emitted from a surface per unit solid angle per unit of area, projected onto a plane normal to the direction of propagation. Also known as brightness and luminous sterance.

B-scope

A cathode-ray display where information is represented visually as spots. Each spot's location is represented by a horizontal coordinate showing its bearing angle, and a vertical coordinate showing...

Babinet absorption rule

The rule stating that positive uniaxial crystals have greater absorption with respect to the extraordinary component of light, whereas negative crystals have greater absorption for the ordinary...

Babinet compensator

A device containing two opposed quartz wedges of equal angle, one wedge being movable along its length by a micrometer screw. The wedges are cut so that their fast directions are along, and...

back channel

A channel for communication with the source in an otherwise unidirectional network, such as a channel that provides interactive features in a cable television network.

back focal length

The distance from the final optic within a system to the rear image point of the system. See focal length.

backlit

Refers to a display or screen that is illuminated from behind; the light is transmitted as opposed to reflected.

backscatter

Backscatter refers to the phenomenon in which radiation or waves are scattered backward, opposite to the direction of the incident beam. This occurs when the incident radiation encounters a target or...

backward-wave oscillator

An amplifying device with a wide tuning range in which an electron gun sends a beam of electrons into a slow-wave structure. The electron beam and the electromagnetic wave move in opposite directions...

bacteriorhodopsin

A light-harvesting protein found in the purple membrane of a micro-organism called Halobacterium halobium. The protein undergoes a photocycle that involves several binary photochemical reactions that...

bakeout

The elimination of gases from the surfaces of a vacuum system by heating the surfaces when the pumping phase is occurring.

Baker corrector

A two-mirror corrector for a parabolic primary mirror that provides anastigmatic performance for large astronomical telescopes.

ballistic camera

A camera that uses multiple exposures to record the trajectory of an ordnance from a ground-level position.

band spectrum

A spectrum that originates from molecules and that is composed of bands which, in turn, consist of many closely spaced lines. Band spectra are used to determine nuclear spin and statistics, and...

band-to-band photoluminescence

The emission of a photon by the return of an excited carrier from the conduction band to the valence band of a semiconductor along a radiative recombination path. The resulting photoluminescence...

bandwidth-limited operation

In fiber optics, the limitation on performance imposed by the system bandwidth rather than the amplitude of the signal.

Barlow lens

A negative lens used to increase the effective focal length of a telescope objective.

barrel distortion

The negative distortion that causes a square grid pattern to be imaged as barrel-shaped.

baseband

The simplest method of transmission on a local area network. The entire bandwidth of the cable is used to transmit a single unmodulated digital signal. Baseband transmission is capable of...

baud

A unit of speed of transmission or receipt of a signal, roughly equal to bits per second; common baud rates are 300, 1200, 2400, 4800 and 9600.

beacon

A device, either visual or electronic, that emits signals to identify set positions for use in the navigation of aircraft and ships along flight paths and channels, or as a warning against entering a...

beam

1. A bundle of light rays that may be parallel, converging or diverging. 2. A concentrated, unidirectional stream of particles. 3. A concentrated, unidirectional flow of electromagnetic waves.

beam candlepower

With relation to the equivalent beam candlepower of a searchlight, the candlepower of a bare source that would produce the same illumination at the respective point if located the same distance away.

beam divider -> beamsplitter

A beamsplitter is an optical device used to divide a beam of light into two or more separate beams, typically by reflecting a portion of the incident light while transmitting the remainder....

beam noise -> noise current

Any noise or current fluctuation that prevents precise measurement of the signal current. Both dark current and signal current have random fluctuations that affect the arrival of pulses. Thermal...

beam profiling

Beam profiling is a technique used to characterize and analyze the spatial intensity distribution of a laser beam. It involves measuring and visualizing how the optical power or intensity is...

beam shuttle

A set of mirrors mounted on solenoids to move them into and out of the path of a laser beam, making it possible for multiple workstations to alternate using the single laser source.

beamsplitter

A beamsplitter is an optical device used to divide a beam of light into two or more separate beams, typically by reflecting a portion of the incident light while transmitting the remainder....

beamsplitting block

A glass block that produces stationary fringes in the region crossed by incident light beams.

beat

The signal formed when two signals, such as light waves, of different frequencies are present simultaneously in a nonlinear device. The frequency of the beat is equal to the difference in frequency...

beat length

A characteristic of optical fiber used to calculate the fiber's ability to maintain polarization. The beat length describes the length required for the polarization to rotate 360 degrees. For a given...

Photonics DictionaryDefinitionsB