A    B    C    D    E    F    G    H    I    J    K    L    M    N    O    P    R    S    T    U    V    W    X    Y   

100baseT

The Ethernet standard for local area networks using twisted-pair cable carrying data at 100 megabits per second (Mbps).

10base2

The Ethernet and IEEE 802.3 standard for base band local area networks using a thin coaxial cable up to 200 meters long and carrying data at 10 megabits per second (Mbps).  Cables connect to network adapters by a BNC connector.

10baseT

The Ethernet standard for local area networks using twisted-pair cable carrying data at 10 megabits per second (Mbps).

3G

3G is the third generation of telecommunication hardware standards and general technology for mobile networking, superseding 2.5G. It is based on the International Telecommunication Union (ITU) family of standards under the IMT-2000.[1].  3G networks enable network operators to offer users a wider range of more advanced services while achieving greater network capacity through improved spectral efficiency. Services include wide-area wireless voice telephone, video calls, and broadband wireless data, all in a mobile environment. Additional features also include HSPA data transmission capabilities able to deliver data rates up to 14.4 Mbit/s on the downlink and 5.8 Mbit/s on the uplink.  Unlike IEEE 802.11 networks, which are commonly called Wi-Fi or WLAN networks, 3G networks are wide-area cellular telephone networks that evolved to incorporate high-speed Internet access and video telephony.  IEEE 802.11 networks are short range, high-bandwidth networks primarily developed for data.

3GPP

The 3rd Generation Partnership Project (3GPP) is collaboration between groups of telecommunications associations, to make a globally applicable third generation (3G) mobile phone system specification within the scope of the International Mobile Telecommunications-2000 project of the International Telecommunication Union (ITU). 3GPP specifications are based on evolved Global System for Mobile Communications (GSM) specifications. 3GPP standardization encompasses Radio, Core Network and Service architecture.

The groups are the European Telecommunications Standards Institute, Association of Radio Industries and Businesses/Telecommunication Technology Committee (ARIB/TTC) (Japan), China Communications Standards Association, Alliance for Telecommunications Industry Solutions (North America) and Telecommunications Technology Association (South Korea). The project was established in December 1998.

3GPP should not be confused with 3rd Generation Partnership Project 2 (3GPP2), which specifies standards for another 3G technology based on IS-95 (CDMA), commonly known as CDMA2000.

850nm

The 850nm infrared LEDs have a very slight reddish glow to the LEDs themselves.   The fact that they do have a very small amount of light that the human eye can see means directly relates to how well they can illuminate.  A 850nm LED will illuminate better than a 940nm LED, all things being equal. The lower the NM number gives it better illumination ability. Operating voltage, amperage, manufacture and even actual size of the LED all play vital roles in the brightness and lifespan of an LED. This is how our 35 LED and 28 LED (850nm) cameras can illuminate as well or better than some 104LED (940nm) cameras.  If a camera has 940nm infrared LEDs it should be labelled as such in the description.

ADPCM (Adaptive DPCM) – redirected from PCM

Is a variant of DPCM that varies the size of the quantization step, to allow further reduction of the required bandwidth for a given signal-to-noise ratio.

Alternating current, AC

AC is electric current that alternates or reverses polarity in a cyclical manner (e.g. 50Hz AC power).

ActiveX

A set of technologies, that allows software components to interact with one another in a networked environment regardless of the language in which the components were created.  Web browsers may come into contact with ActiveX controls, ActiveX documents, and ActiveX scripts. ActiveX controls are often downloaded and installed automatically as required. 

Alarm

An electrical, electronic, or mechanical device that serves to warn of danger by means of a sound or signal.

Alarm Function

The Lotus BC-23XP series provides an Alarm function that detects changes in AF, AE, or both AF and AE levels of an image and outputs an alarm signal as required to external equipment via its control interface using VISCA protocol.  This feature is ideal for automatically performing functions such as sounding an audible alarm or triggering an electric door strike to lock or unlock a door when focus or luminance levels change.  Users can designate multiple detecting areas from any of 16 vertical and 16 horizontal blocks.  In addition, these cameras feature a DAY/NIGHT mode that can output an alarm signal via the VISCA protocol in response to a change in the designated brightness/darkness level.

Alloy

It is a combination of two or more different polymers/metals that usually combined to make use of different properties of each polymer/metal.

American Standard Code for Information Interchange, ASCII

It is a standard single-byte character encoding scheme using for text-based data. ASCII uses designated 7-bit or 8-bit number combinations to represent either 128 or 256 possible characters. Standard ASCII uses 7 bits to represent all uppercase and lowercase letters, the numbers 0 through 9, punctuation marks, and special control characters used in U.S. English. Most current x86-based systems support the use of extended (or "high") ASCII. Extended ASCII allows the eighth bit of each character to identify an additional 128 special symbol characters, foreign-language letters, and graphic symbols.

Ampere

It is a standard unit of current, defined as the amount of current that flows when one volt of electromotive force (EMF) is applied across one ohm of resistance.  One ampere of current is produced by one coulomb of charge passing a point in one second.

America Wire Gage, AWG

AWG is also known as the Brown & Sharpe wire gauge, is a standardized wire gauge system used since 1857 predominantly in the United States for the diameters of round, solid, nonferrous, electrically conducting wire.  The cross-sectional area of each gauge is an important factor for determining its current-carrying capacity, the smaller the AWG number, the larger the wire diameter.

Analogue Signal

It is an electrical signal which varies continuously, not having discrete values.  Analogue signals are copies or representations of other waves in nature.  An analogue audio signal, for instance, is a representation of the pressure waves which make up audible sound.

Angle Of View

It is the area of a scene that a lens covers or sees. Angle of view is determined by the focal length of the lens. A wide-angle lens (short-focal-length) includes more of the scene-a wider angle of view-than a normal (normal-focal-length) or telephoto (long-focal-length) lens.  It can also be explained as the extent of the view taken in by a lens. For any particular film size, it varies with the focal length of the lens. It is usually expressed on the diagonal of the image area.  Basically, there are three types of angles which can be measured (based on horizontal, vertical and diagonals of the film frame), the lens must be designed to cover the widest angle in the diagonal direction. Thus, the angle of view is the angle between imaginary lines drawn from the opposite ends of the film plane to the second nodal point of the lens.  All objects within this angle will be recorded by the lens on the film.

Anti-Aliasing Filter (Redirected from Optical low-pass filter)

Is a filter used before a signal sampler, to restrict the bandwidth of a signal to approximately satisfy the sampling theorem.  Since the theorem states that unambiguous interpretation of the signal from its samples is possible only when the power of frequencies outside the Nyquist bandwidth is zero, the anti-aliasing filter would have to have perfect stop-band rejection to completely satisfy the theorem. Every realizable anti-aliasing filter will permit some aliasing to occur; the amount of aliasing that does occur depends on how good the filter is.

Aperture

It means the lens opening.  The hole or opening formed by the metal leaf diaphragm inside the lens or the opening in a camera lens through which light passes to expose the film.  The size of aperture is either fixed or adjustable.  Aperture size is usually calibrated in f- numbers-the larger the number, the smaller the lens opening.  Aperture affects depth of field, the smaller the aperture, the greater is the zone of sharpness, the bigger the aperture, the zone of sharpness is reduced.  The hole or opening formed by the metal leaf diaphragm inside the lens; controls amount of light and depth of field, prevents vignette and reduces lens aberrations; the size of the aperture is indicated by its f-number, i.e., the ratio of the diameter of the opening to the focal length of the lens; a large aperture is indicated by a small numerical f-number.

Aspect Ratio

A ratio of width to height in images.  A common aspect ratio used for television screens and computer monitors is 4:3. High-definition television (HDTV) uses an aspect ratio of 9:16.

Aspherical lens

A lens whose curved surface does not conform to the shape of a sphere; lenses are usually ground or molded with spherical surfaces; because a spherical surface lens has difficulty in correcting distortion in ultra-wide angle lenses or coma in large-aperture lenses brought about by spherical aberration, an aspherical lens is used.  Special design of aspherical lenses reduces light loss in scenarios where you need to compensate intensive light reflections in the picture by adjusting maximum aperture. Camera therefore has much higher light sensitivity.

Asymmetric DSL, ADSL

Broadband digital communication connection operates over standard copper telephone wires. It requires a domain-specific language, DSL modem, which splits transmissions into two frequency bands: the lower frequencies for voice (ordinary telephone calls) and the upper band for digital data, especially for connection to the Internet. Data can be transferred via DSL at much higher rates than with ordinary dial-up modem service; the range of DSL signals, however, is very small. Connections can be made only within a few miles of the nearest transmitting station. DSL and "xDSL" are umbrella terms under which a variety of protocols and technologies fall. ADSL is a popular type of DSL in which most of the bandwidth of the connection is devoted to downloading data from the network to the user, leaving only a small-scale connection for uploading data.

Attenuation

The decrease in magnitude of a signal as it travels through any transmitting medium, such as a cable or circuitry.  Attenuation is usually expressed logarithmically as the ratio of the original and decreased signal amplitudes. It is usually expressed in decibels (dB).

Audio

A term used to describe sounds within the range of human hearing (20 Hz to 20 kHz).  Also used to describe devices which are designed to operate within this range.

Audio Video Interleave, AVI

AVI is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows technology. AVI files can contain both audio and video data in a file container that allows synchronous audio-with-video playback.  Like the DVD video format, AVI files support multiple streaming audio and video, although these features are seldom used. Most AVI files are supported by Microsoft, and are unofficially called "AVI 2.0". 

Auto Electric Shutter, AES

It is often used to describe the electronic process of controlling exposure time on a light sensor.  Many video cameras provide the ability to adjust their shutter.  The benefit of AES is to increase the quality of the object but it will decrease the life span of cameras.

Automatic Exposure, AE

The central processing units of modern cameras are programmed with data for huge numbers of possible viewing situations so that automatically correct exposure—if desired—is practically assured.

Automatic Level Control, ALC

A part of the electronics of an automatic iris lens that has a function similar to backlight compensation in photography.

Auto Focus, AF

System by which the camera lens (most popular) or the camera body automatically focuses the image of a selected part of the picture subject.

Automatic Gain Control, AGC

Is an adaptive system found in many electronic devices. The average output signal level is fed back to adjust the gain to an appropriate level for a range of input signal levels. For example, without AGC the sound emitted from an AM radio receiver would vary to an extreme extent from a weak to a strong signal; the AGC effectively reduces the volume if the signal is strong and raises it when it is weaker.

Automatic Iris Lens

These lenses have an electronic circuit inside, which controls the iris by electronic feedback.  The lens usually has a 4-pin connector which connects to the camera, where it gets its power supply (9V DC) and its video signal.  The lenses electronics then analyses the video signal level and acts accordingly.  If there are changes to light conditions, the iris then adjusts accordingly to provide the best picture possible.  For example, if the sun comes out on a very clear day, the iris will close to be very small, and in the evening as it gets darker, the iris will open up to allow more light in.  These lenses are ideal for all applications, as they provide the most flexibility.

Auto Tracing White Balance, ATW

ATW is a feature that automatically adjusts the camera's white balance to adapt to changing light conditions.  With ATW, the camera can compensate for a color temperature range of between 2,000 K and 10,000 K, allowing for operation under a variety of lighting conditions, including special light sources such as a sodium vapor lamp.  When operating under natural light, incandescent lamps, or fluorescent light sources, ATW which compensates for a color temperature range of between 2,500 K and 6,000 K - is ideal for reproducing color images closer to what we see with our eyes.

Auto White Balance, AWB

Most cameras have an "auto-white balance" feature that performs its own white balance without any input from the user.  Unfortunately, the auto-white balance is not particularly reliable and it is usually preferable to perform this function manually.  On most cameras, it means completely automatic.  On professional-level cameras, it can mean the white balance operation which is actually quite manual.  This is because in professional situations, a manual white balance" can mean altering colours using specialised vision processing equipment or other method of adjusting colours.

AV

The Aperture value, usually refer to aperture settings.