Analogue

Continuously varying signal (not digitised).

Cassette

Recording medium with both take-up and supply spools enclosed in a semi dustproof container

Amplitude

Level or intensity of Signal.

CCU

Camera Control Unit. Allows remote control of many camera engineering functions.

Aspect Ratio

Ratio between height and width of picture.

CCD

Charge Coupled Device. Light sensitive chip used for optical scanning.

Assemble Edit

Editing where material is combined to produce
a final version of a video movie.

CD

Compact Disc. Laser read disc digitally encoded for perfect reproduction.

Attenuator

Device designed to reduce the strength of an
optical, acoustic or electronic signal.

Chroma Key

Technique which allows a vision mixer to substitute a saturated colour (blue or yellow) in a picture for another source (captions, slides, film).

Audio Dub

Re-recording the audio track of a video recording
without disturbing the video signal.

Chrominance

Part of video signal that conveys colour information.

Azimuth

Angle between the gap of a tape head and the plane of head to tape movement.

Chrome Audio
Tape

Recording tape with higher coercivity and remanence than ferric oxide tapes though less than pure metal.

Back Focus

Adjustment of the taking lens so that the lens shows the same F value as the first relay lens.

Coercivity

The magnetising force required to reduce the magnetism of a sample to zero (used when testing tape).

Backing Track

Pre-recorded audio accompaniment.

Colour Bars

Specific strips of colour used to test image quality.

Back Projection

Where screen receives the picture from behind.

Component

Recording of colour signal in separate component parts, e.g. chrominance and luminance, to avoid artefacts caused by composite methods.

Bandwidth

A portion of the frequency spectrum used for audio, video or radio.

Composite

Signal comprising luminance and chrominance using one of the coding standards, e.g. PAL.

Bias

Magnetic field applied to the recording head separately from the programme signals itself to better align tape type.

Contrast

A gain control range between dark and light levels.

Blanking

Period during picture while scanning spot returns to top of screen.

Control Track

The portion along the video tape which contains the synchronisation information to control playback.

Blue Only

Mode that enables VTR noise to become more visible on a screen.

Convergence

Accuracy of colour registration.

BNC

Type of connector commonly used for video signals.

Cross-talk

Interference of one signal with another.

Boom

Microphone or lighting support set nominally parallel to the floor usually held by a vertical stand.

DAT

Digital audio tape for high quality digital audio.

Burn In

Used to be prevalent in tube cameras where image was retained semi-permanently on the target area of the camera pick-up tube caused by shooting  excessively bright objects.

Decibel

The relative level or volume of any particular sound in relation to another sound, sometimes used subjectively.  For an amplifier with an output voltage 100 times the input voltage, the amplification may be computed as follows:   20 log 100/1 = 20 log 10 x 10 = 40 decibels

Burst Flag
Pulse

Pulse signals for Horizontal scanning frequency used to extract from the colour subcarrier wave a continuous wave  which has an established phase relationship  with colour signals for transmission.

Degausser

Device for reducing  residual magnetism.

Burst

Short period of colour subcarrier added to each line sync period.

Digital

Signals formed of series of coded pulses (numbers) as distinct from continuous analogue signals.

BVU

High band recorder/player (Broadcast Video U-matic) not compatible with standard PAL u-matic.

DIN

Deutscher Industrie Nornenausschus, a German standards body.

Capstan

The rotating motor driven shaft that governs the linear speed of the tape in video or audio tape transports.

Dissolve

Vision mixer effect where picture fades out as second picture fades in.

Caption

Term for artwork, lettering or diagrams used in video programmes.

Downstream
Keyer

A caption superimposer on mixer output, i.e. not affected by the vision mixer standard.

Caption
Generator

In the domestic market an add-on to cameras or VTR’s to label and enhance recordings.

Dropout

Loss of signal during replay caused by lack of magnetic coating on a portion of videotape, or by particles of dirt or grease.

Cardiod Microphone

Microphone with heart shaped sensitivity response.

Dropout
Compensator

Device which reduces subjective effect of videotape dropout by repeating a previous signal.

Drum

Mechanical assembly containing the headwheel in a helical scan VTR.

Graded

In monitors.  1 is full broadcast colour balance standard.  2 is general purpose and 3 is a converted domestic receiver.

EBU

European Broadcasting Union.

Graphic
Equaliser

Device which allows for the shaping of audio frequency responses in a visual manner.

Editing

Assembling a programme by transposing or combining separate recorded sequences either by physically cutting and splicing tape (audio or film) or selective electronic copying.

Guard Band

Blank region between recorded magnetic tape tracks to eliminate crosstalk.

Edit Controller

Electronic console which allows the EDITOR to assemble or insert sections of a programme. Special effects and other ancilliary equipment may be controlled by this unit. 

HAD

Hole Accumulated Diode.

Editing Equipment

Equipment used to compile a finished program from tapes and other sources.

Head

Devices for the recording and retrieval of magnetic information.  VTR’s can employ several kinds of head; rotating video heads an audio head, a control head and  an erase head.

Editor

Person responsible for assembling sections of often non-sequentially  shot action and sound into a coherent pattern which reflects the vision of the DIRECTOR.

Helical Scan
System

This system used in video recorders and DAT recorders wraps the tape around a rotating drum so that the pattern recorded on the tape is a series of long, parallel and diagonally-slanted tracks

EFP

Electronic Field Production similar to ENG but often with multiple cameras.

High Band

Recording in which the luminance FM deviation is from 4.8 to 6.4 Mhz and the colour under frequency is 924 Khz.

Electret
Microphone

Similar to a condenser microphone but with a permanent charge on the foil so avoiding the need for a polarising voltage.

Horizontal
Resolution

The number of horizontal lines which are used to make up one full frame (two fields) of a video picture.  The greater the number of lines the better defined the picture.

ENG

Electronic News Gathering.

Hue

Colour “tone” control on some TV/monitors.

Fade

Gradual increase or decrease in audio or video signal strength.

Hyper HAD

HAD sensor with a layer of micro condensing lenses over each pixel.

Feedback

Where sound or pictures loop back on themselves producing whistles or multiple images.

Image Enhancer

Electronic device for increasing picture quality.

Field

Even or odd line component of a frame in an interlaced TV system (see Frame).

Image Intensifier

Enables a camera to operate under very low light levels.

Flagging

Vertical break up at top of picture on poor VTR recordings.

Infrared

With wireless remote control pulses for video recorders are transmitted by an infrared light emitting diode. Infrared radiation is invisible.

Flying Erase

Facility for erasing single video tracks from a rotating head instead of a fixed head.

Insert

Editing where material replaces a section within the existing recording.

F Number

Camera iris calibration obtained by dividing the focal length by the effective iris diameter.

Interlace

System of making up a complete TV picture by scanning half of the total number of lines making up the frame in one pass of the electron beam, followed by a scan of the missing interleaving lines to complete the field.

FIT

Frame Interline Transfer.

Intervideo
London
NW8

Established in 1977 to provide the broadcast television,  film and video industry with a highly professional, responsive service which is now the benchmark for companies operating in standards conversion and broadcast duplication.   Pursuit of excellence for more than 29 years.

FRAME

Stationary television or film image.  In European television 25 frames per second are scanned to give the impression of continuous movement.  Each frame is normally composed of two interlaced fields.

Iris

Device for reducing light intensity, typically in the camera.

Frame Code

Absolute address system for each frame, recorded in the vertical blanking period.

Jitter

Distortion in the television picture due to lack of synchronisation of the video head, Capstan, etc.

Gain

Ratio of amplification of attenuation usually expressed in decibels.

Keyer

Vision mixer effect that cuts a hole in the main picture whose outline is determined by another camera output.

Genlock

Means of locking local SPG into incoming or pre-recorded video to provide full synchronisation.

Lavalier

Microphone suspended from speaker’s neck.

Leader

Uncoated coloured tape used to separate start or finish items. Also refers to film stock used for same purpose.

Raster

Unmodulated TV picture comprising horizontal lines.

Lens

Optical device for collecting light from a scene and directing it towards the CCD or film.

RCTC

Rewriteable consumer time code, 8mm consumer time code written without reference to audio or video.

Low  Band

Recording in which the luminance FM deviation is from 3.8 to 5.4 MHZ and the colour under frequency is 685 KHZ.

Resolution

Ability of the picture to resolve fine detail.  The greater the resolution the sharper the picture.

Luminance

Monochrome component of colour signal.

Retentivity

Maximum remanent magnetism possible in a magnetic material.

Lux

Basic metric unit of illumination.

Rostrum Camera

A fixed camera mounted vertically for shooting complicated graphics or animation.

Master

First generation recording.

RS 232

Serial communication standard used mainly by computers.

Mini Jack

3.5mm jack plug and socket system.

RS 422

Serial communication standard used for broadcast equipment control.

Mistracking

Occurs when the video heads do not scan the recorded tracks correctly, causing visible disturbances on the screen.  This can usually be eliminated by adjusting the tracking control.

Scart Connector

Or peritel 21 pin euro standard connector used to carry various signal information including audio and video.

Modulator

Device to convert audio and video signals into high frequency transmission signals.

S Connector

Video connector used for video signals with separate luminance and chrominance (YC) - normally 4 pin as in HI-8 or S-VHS.

Monitor

Video display screen or audio loudspeaker.

Secam

Sequential colour with memory, system used in France.

NAB

National Association of Broadcasters.  Used as a term for standards specified by the organisation.

Sequential
Switcher

Typically a device used in surveillance to provide dis-continuous monitoring of two or more outputs on a single display screen.

NAB Cartridge  

A standard endless loop cartridge.

Server

A computer terminal dedicated to ‘serving’ stored data to other computers connected to a network. Multiple servers may be connected in areas such as electronic newsrooms and the Internet.

NAB Spool

A 26.6cm diameter tape spool with a large central hole.

Servo

Electronic regulator for a motor providing precise control.

NTSC

National Television Standards Committee, standard used in the United States and Japan.

Skew

Vertical break up of picture on poor VTR recordings.

Omni-Directional

Equally sensitive in all directions.

Skew Regulator

This adjusts tape tension when a tape is changed to avoid skewing distortion at the top of the screen resulting from the video track length altering after the changeover.

PAL

Phase alternating line colour TV system used in Great Britain and other European countries (not France).

Slave

Machine (usually VTR) controlled by a second machine.

Pan

To swivel a camera about a fixed axis.

S/N

Signal to noise ratio (normally the greater the better).

Pedestal

Black level or set-up in a composite video signal. (EBU = 300mv  NTSC = 375mv) Pedestal is zero in COMPONENT or DIGITAL signals.  Also term for  a  studio camera mount.

SPG

Synchronised Pulse Generator used to produce master timings for studios.

Phantom Power

Power fed through microphone cable from mixer, etc. to mike without interfering with the audio signal.

Standards Converter

Used to convert TV pictures from one standard to another, typically NTSC to PAL.  The highest specification is that with ‘motion compensation’ especially  ALCHEMIST with Phc. (Phase Correlation)

Post Production

The final phase in video production in which editing and dubbing are carried out.

Still Frame

Continuous reproduction of a stationary helical scan video tape.

TBC

Time Base Corrector.

VHS

Video Home System 1/2 inch cassette system.

Time Base
Corrector

Short term signal store designed to reduce timing errors and litter in VTRs.

VITC

Vertical interval timecode.

Timecode (LTC)

Longitudinal, absolute address for each frame in hours, minutes and seconds recorded on a dedicated track.

VITS

Vertical interval test signal.

Time Lapse

Recording of a single frame(s) with a time interval between each recording.

VTR

Video Tape Recorder.

Tracking

Adjustment for optimum head alignment on recorded track.

White Balance

Most desirable condition is when a white subject is reproduced as white on a screen indicating that the red, green and blue are well balanced.

Triax

Coaxial type cable with extra screen to provide camera power.

Wipe

Effects technique in which one scene appears to push another off screen.

Umatic

3/4 inch video cassette format developed by Sony.

Wow and
Flutter

Slow or fast changes respectively in the speed of a tape transport which causes a variation in audio pitch.

Underscan

Reduction on display by approx. 10%.

YUV

The three constituents of a component video signal:  Luminence with  two colour difference  signals.
Y = luminence  U = Blue minus luminence   V =Red minus luminence 

Vertical Interval

Non visible part of a video picture. The vertical interval carries Synchronisation Pulses, VITC, Telext , Closed Captions (subtitles when de-coded) and Identification Pulses.

Zoom

Lens system with movable elements to provide adjustable magnification.

1)

A concentration of small scratches in the loading and unloading sections, but nowhere else, are likely to be caused by excessive tape tension during loading  and unloading.

2)

A number of fairly deep scratches extending from the loading section through the first several minutes and then getting fewer are often caused by the VTR mechanism being slightly dirty hence dirt is dislodged through the motion of the tape.

3)

One or several scratches extending from the loading section to where recording ends is likely to be  caused by scratches on the VTR mechanism or a contaminated tape path.

Scratches caused by the video head are due to the VTR being left in PAUSE or STANDBY for too long.

1)

Incorrect adjustment of VTR transport mechanism

2)

Misalignment of tape guides in video cassette.

High tape  tension

*Edge damage causes drop outs and generally affects sound quality.

1)

Timing adjustment between supply and take up reel during FF-STOP or REWIND-STOP.

2)

Misalignment on reel break during unloading.

3)

Tape becomes slack or tangled inside cassette shell.

Wrinkles and breaks can affect sound, give many drop outs, affect synchronisation and halt tape travel.

“Drop Outs"
 (Hits)

A VTR must record extremely short wave lengths into very narrow tracks on the tape.  Even the smallest imperfections in the tape’s magnetic layer will therefore degrade the reproduction.  These imperfections appear as white marks or “drop outs” (hits) on the screen.  Severely worn video heads and improper recording current are also causes of drop outs.