Glossary
Acceptance angle Horizontal angle of view of a camera lens.
AGC See Automatic gain control.
Ambient General background noise level or basic illumination.
Amp (A) Ampere, unit of electrical current.
Amplitude modulation A method of transmitting information, by changing the amplitude (strength) of a high-frequency (carrier) wave in proportion to the amplitude of the lower-frequency signal we wish to transmit. The amplitude-modulated carrier is subsequently detected (demodulated) and the original lower-frequency signal recovered.
Analogue An electrical signal that is proportional to the originating source, usually pictures, sound or control signals.
Arc A largely obsolete powerful carbon-fed lamp.
Aspect ratio The ratio between the horizontal and vertical dimensions of the television picture frame. This is currently 4:3 for all television systems but new high-definition systems using 16:9 are likely to be the standard in the future.
Attenuator A resistance network introduced into a circuit which enables the amplitude of a signal to be reduced without creating distortion.
Audio oscillator Apparatus which generates sinusoidal oscillations at frequencies in the audio waveband.
Aural sensitivity network A filter which ‘has the characteristics of the human ear’ (a precise definition has yet to be internationally agreed).
Autocue Trade name of a prompting device mounted on a camera so that the presenter can read the script whilst looking directly at the lens.
Automatic gain control (AGC) Device that reduces the dynamic range of an electrical signal.
B-format A one-inch broadcast recording system developed by Bosch-Fernseh.
Back projection (BP) Nearly obsolete method of projecting slides or film onto a translucent screen from the rear to provide a scenic background.
Backcloth (backdrop) A painted background, usually on canvas, to a set.
Background (BG) The part of a scene farthest from the point of interest, either vision or sound.
Background camera The camera providing the infilling picture that replaces the keying colour in colour separation overlay.
Backing (1) Background scenery. (2) A group of singers or instruments supporting the leading performers.
Backlight Light directed towards the camera from behind the subject, occasionally called rim light or hair light.
Baffle (1) A screen to deflect sound. (2) Louvred shutter for attaching to the front of luminaires.
Bandwidth The range of frequencies encompassed by an electronic system transmitting television pictures (video) or sound (audio) signals, the more detail required the higher the bandwith needed.
Barndoors Four flaps fitted to a spotlight which are used to control the shape of the light beam.
Barrel see Lighting barrel.
Betacam A combined camera and recorder.
Betacam SP A recording format widely used in broadcasting and elsewhere.
Betamax A domestic cassette format (obsolete).
Bias A high-frequency signal which is added to the audio signal in an analogue tape recorder.
Black burst Sync pulse signal that includes the colour burst used for synchronising picture sources, also known as Colour Black.
Black edge Facility for electronically creating a thin black edge around light overlaid lettering to improve legibility against backgrounds of similar tone.
Black level The lowest amplitude of a picture signal, representing black in a scene.
BNC The most common video connector used on equipment.
Boom A telescopic arm for positioning a microphone.
BP See Back projection.
Brace A strut to hold up scenery.
Brace weight An iron weight designed to hold a brace in position.
Brightness the amount of light emitted or reflected by a surface per unit area.
Bulk eraser Device designed to erase magnetic recordings.
BVU Near broadcast standard (or high band) U-matic (¾-inch) cassette recorder, now almost confined to the non-broadcast market.
C-format Broadcast standard analogue system of video-recording using 1 - inch wide tape now being superseded by digital formats.
C-mount A lens-fixing mount used on non-broadcast TV cameras.
Camera angle The horizontal angle of view of the camera lens.
Camera cable Cable connecting the camera to its control unit (CCU) or recorder.
Camera card Cue card showing a cameraman’s own shots.
Camera channel Complete television camera chain including camera, control unit (CCU) and power supply.
Camera control unit (CCU) The device containing most of the control and line-up circuits of a camera that do not have to be in the camera itself.
Camera head See pan and tilt head.
Camera headlamps See Headlamp.
Camera left (Cam L) Left-hand side of the set from cameraman’s point of view.
Camera mountings Camera supports including tripods, pedestals etc.
Camera right (Cam R) Right-hand side of the set from the cameraman’s point of view.
Camera script Script marked up with shot numbers, cameras, cutting points, lighting and sound cues.
Camera tower Scaffold tower for high-angle shots.
Candela Unit of luminous intensity
Cans Accepted slang for headphones.
Capstan Main drive shaft for tape motion in a tape recorder.
Caption card Stiff card on which pictures or lettering are mounted usually black measuring 30 × 23 cm (12 × 9 in) or 50 × 38 cm (20 × 15 in).
Caption scanner Apparatus for televising 35 mm transparencies or small graphics.
Caption stand Stand on studio floor on which captions are placed.
Captions Photos, printed cards, other graphics and slides.
Cardioid microphone Microphone whose directivity pattern (polar diagram) is heart-shaped, resulting in maximum sensitivity at the front and very low sensitivity at the rear.
Cartridge A closed loop of tape or film in a near dust-proof container.
Cassette A near dust-proof enclosure containing reels of tape or film.
CCD Charge-coupled device, a light-sensitive material for converting light to electrical impulses.
CCU See Camera control unit.
Chalnicon A sensitive type of camera tube used in specialised applications.
Channel A general term for a succession of apparatus having a combined function. In a sound mixing desk, for example, a section handling the output of one audio source (e.g. microphone—amplifiers—fader—filtering, etc.) as opposed to a group of sources. A vision channel embraces the complete video generating system for a single picture source (e.g. camera—amplifiers—associated supplies and scanning systems—switching circuits—distribution amplifier, etc.). A lighting channel is the complete lighting circuit supplying a particular luminaire (e.g. power routing—switching—patching—dimmer—plugging, etc.).
Character generator Electronic generation of lettering or numbers for display on a TV screen using a form of keyboard.
Chroma key See Colour separation overlay.
Chrome dioxide tape A high coercivity, high remanence recording tape.
Chrominance The colour information in a video signal.
Cinemoid A proprietary branch of self-extinguishing colour gel used to tint light sources.
Clean feed An audio signal minus one or more of the contributing sources.
Clipper A video limiter.
Clipping level The threshold to which a clipper is set.
Clock A mechanical or electrical clock that counts down into a programme sequence or shot.
Clogging A partial loss of picture due to loosened tape particles causing a reduction in head-to-tape contact on a tape recorder.
Closed circuit Programme viewed but not transmitted.
Co-axial cable Cable consisting of an inner core and an outer screened braiding for carrying primarily video, UHF and VHF signals.
Coder Circuity for encoding the three separate red, green and blue components of a colour picture to produce a single composite signal. Whereas the original separate RGB signals required three individual transmission channels the encoded signal may be transmitted over a single line (cable or radio) and decoded to recover the separate components at the receiving point.
Coding (or encoding) The method of conveying colour information in a conventional television system, using a variety of techniques known as PAL. SECAM or NTSC. Other types of coding are used, for instance to combine digital audio sound with a vision signal over the same route or to combine teletext information with the video signal
Colour bars A test signal consisting of eight vertical coloured stripes.
Colour burst Several cycles of the colour sub-carrier transmitted at the beginning of each line in order to synchronise receivers to reproduce colours correctly.
Colour separation overlay (CSO) or chroma key The combination of the two pictures where one picture replaces a pre-determined colour in another picture (usually blue). In the latter case the desired part of the picture (the foreground) should not contain blue.
Colour synthesiser or matte generator A device for producing colours synthetically. Often used for colouring letters or backgrounds on black and white captions.
Colour temperature A scale for measuring the colour of a light source. Colour temperature is measured in kelvins (K), with 0°K = ‒ 273°C. Tungsten lights are approximately 3200 kelvins, daylight around 5600 kelvins. The higher the figure, the more blue the light appears to the eye.
Composite video Signal containing vision and synchronising pulses.
Compression Control of audio sources to reduce their dynamic range.
Compressor Device to reduce the dynamic range of an audio signal.
Console A lighting or sound control desk.
Contrast The ratio of brightness in a scene.
Control line A telephone circuit between two areas for technical or production purposes.
Control track A signal recorded on a videotape to control the machine during replay.
Convergence the combining of Red, Green and Blue rasters on a colour monitor screen to obtain a single raster.
Convergence test chart A chart containing a grid of vertical and horizontal lines to enable adjustment of the images formed by the three primary colour sensors in the camera to be perfectly superimposed.
Coving A concave board at the front of a cyclorama to conceal the floor line.
Cox-box A proprietary make of colour synthesiser.
Crab To move a camera sideways.
Credits Programme titles or end titles.
Cross colour An interference pattern on fine detail such as a herringbone jacket.
Cross fade To mix from one source to another (vision, lighting or sound).
Crosstalk Interference between one source and another (vision or sound).
CRT Cathode ray tube.
Crushing Loss of gradation in a picture due to distortion of the contrast range of a camera.
CSO See Colour separation overlay.
Cue light A small light mounted on a floor or table stand in the studio that is switched on from the control room in order to cue an artist
Cue track Sub-standard audio track, used for cueing or guide purposes
Cut instantaneous change from one picture to another.
Cyc track A rail with runners on which a cyclorama is hung
Cycles per second See Hertz.
Cyclorama (cyc) A plain backcloth stretched taut around a studio to provide a backing.
dB Decibel, a logarithmic measure of sound intensity. Also used for comparing signal levels.
dBA A measure of sound levels in decibels weighted by the subjective effect on the human ear.
Decoder Circuitry for retrieving the individual Red, Green, Blue colour signals from a coded colour video signal.
Definition The ability to reproduce fine detail in a picture.
Defocus The blurring on an image optically or electrically.
Degausser Device for demagnetising tape heads or videotapes.
Depress To lower a camera height (on a pedestal mounting, by reducing the column height).
Depth of field The distance between the nearest and farthest points from a camera that are within acceptable focus. Depth of field varies with lens aperture (stop), focused distance, and the focal length of the lens.
Dichroic mirror A surface-coated glass filter which permits certain parts of the visible spectrum to pass through while reflecting others. Used in colour television cameras and telecine systems to analyse the full-colour scene into RGB components. A form of dichroic filter is used as a heat filter in projector systems to protect the film material from infra-red and heat rays.
Digital The representation of video, audio or control signals by means of a train of pulses.
Dimmer A device for control of lamp brightness.
Directivity pattern A graphical plot representing the relative performance of a device at different distances and in various directions. It can show the sensitivity variations, or changes in frequency response, of a microphone. Similarly it can demonstrate the way in which the output of a device (e.g. a lamp or a loudspeaker) alters with angle and with distance.
Director The person responsible for the organisation, creative interpretation and presentation of a particular programme. The functions of a director vary somewhat from one organisation to another.
Dissolve An effect of fading one picture out whilst another is faded in.
DNR Digital noise reduction.
Dolby Trade name for a particular type of noise reduction.
Dolly A wheeled camera mounting, usually larger than a pedestal or more suited to uneven surfaces.
Double band Separate pictures and sound tracks (known as Sepmag) shown on a film projector.
Double-head Film projection and sound on separate synchronised projectors.
Downstage The activity area nearest to the camera. To walk downstage means to walk towards the cameras.
Dropout Momentary break in the recording track on videotape causing a flash on one or more lines on the screen.
Drum The assembly containing the rotating heads on a videotape machine.
Dual source Light with a hard source at one end switchable to a soft source at the other.
Dubbing (1) Copying a recorded sequence or programme. (2) Audio manipulation of a recorded video sequence or programme.
Dynamic range Variation between the highest undistorted sound level from a device and the inherent background noise level. Similarly for video signals.
E to E Electronic to Electronics, i.e. a signal passing through a device but not acted upon by that device.
Echo Reverberation, often added artificially by means of electronic devices. Edit suite An area containing two or more tape machines configured to join sequences together.
Editing Assembling a programme by joining separate sequences together in an ordered way.
Effects Sound or visual material added to a scene to create atmosphere.
Effects track Sound track of effects excluding dialogue and music.
EFP Electronic field production, using portable TV equipment. The programme requirements are technically more complex than news and current affairs.
Electret A permanently charged material used in some types of electrostatic microphone.
Electronic editing Videotape editing from one or more videotape machines to another, equipped to make invisible joins electronically.
Electrostatic microphone Microphone in which the conducting diaphragm upon which the sound impinges forms one plate of a capacitor. Capacitance changes caused by diaphragm movements are converted into an output voltage.
Elevate To raise camera height.
Encoding See Coding.
ENG Electronic news gathering, using videotape as the recording medium and generally lightweight equipment.
f-number Calibration of lens aperture, calculated by dividing the focal length by the effective iris-aperture diameter.
Fade To increase or decrease the amplitude of a picture or a sound, as in ‘fade-up’, ‘fade-down’, or fade-in, fade-out.
Fader Lever for fading sound, pictures or lights.
FAP or FP See Front axial projection.
Field One half of the interlaced television frame, one field consisting of all the odd lines in a picture the other the even lines.
Figure-of-eight Type of microphone directivity pattern (so called from its polar diagram shape). The true three-dimensional pattern would be two spheres in contact with the microphone at the point of contact.
Filler light Soft light that reduces the density of shadow in a picture.
Film recording Transfer of an electronic video signal to film.
Firelane Lane marked on the studio floor to limit the acting area and leave a free passage between the set and the studio wall.
Fisheye lens An extremely wide angle lens.
Fishpole Hand-held microphone boom.
Flare Effect of a bright source of light shining directly onto a lens, sometimes done for effect but more often an undesired aberration.
Flat A flat piece of scenery usually made of stretched canvas or hardboard on a flat wooden framework. Sometimes with architectural features such as a door or window.
Flat light Even illumination of a scene, giving no modelling and a two-dimensional appearance.
Flood A soft source of light.
Floor lamp A light source on a stand.
Floor manager The person responsible for the productional organisation (including performer cueing) and general discipline in the studio. He is the director’s representative on the floor.
Floor paint A paint used for studio floors that can be washed off, often used in conjunction with a patterned roller.
Floor plan Plan of a studio (usually to a scale of 1:50) showing the disposition of sets, furniture and equipment.
Flutter Rapid variation in speed of a recording medium.
Flying erase head A rotating video head used to erase video tracks when electronic editing on videotapes.
Flying spot scanner Device using a plain raster viewed by image sensors through film or slides to produce a picture free of registration error.
Focal length Distance from the optical centre of a lens to the point of focus of an object at infinity.
Foldback Sound fed to a loudspeaker on the studio floor from the sound mixer.
Frame Television picture comprising two fields.
Frame store (synchroniser) Device that can store an incoming signal and replay it in synchronism with a local reference, thus enabling remote pictures to be mixed with local pictures.
Frequency modulation (FM) A method of transmitting information by changing the frequency of a high-frequency carrier wave in proportion to the amplitude of the lower-frequency signal we wish to transmit. (The amplitude of the carrier remains unchanged.) The frequency-modulated carrier is subsequently demodulated to recover the original signal.
Fringing Colour errors at the edge of coloured areas in a picture.
Front axial projection (FAP) The projection of a background scene through a half-silvered mirror on to a highly reflective screen viewed on axis by a camera through the mirror. Now rarely used.
Gain Measure of amplification or attenuation, usually in decibels.
Gallery Production control room.
Genlock The control of the local pulse generator by a remote source to make pictures from both areas synchronous at the mixer.
Gobo Metal ‘cut-out’, used in projection of abstract shapes, clouds, windows, etc.
Grams Record playing equipment.
Grey scale Test card showing graded steps from black to white, used for line-up of colour cameras and colour monitors
Grille Test signal consisting of vertical and horizontal lines on a contrasting background.
Ground row (1) Floor lamps used to light a cyclorama or backcloth. (2) Scenic cut-outs, usually floor standing and of reduced height; can be used to hide lighting ground row.
Group In a sound desk two or more channels may be faded up together, and so combined into a group. A single group fader then controls all these sources simultaneously.
Guide track (1) Pre-recorded sound track used to synchronise action. (2) Sound track recorded during shooting to serve as a guide during post-synchronising, but not used in the main programme.
Gun microphone Type of microphone with a narrow pick-up angle. Such microphones embody a slotted or perforated tube, typically about 0.5 m long.
Gyroscopic errors Unstable recording due to a portable VTR being moved around during recording.
Hard light Luminaire that produces clearly defined shadows, e.g. a spotlight.
Harmonic An oscillatory motion (mechanical or electrical) that is a multiple of a fundamental frequency.
Harmonic distortion Changes in the total harmonic content in a signal caused by non-linear circuits.
Head Pan and tilt device supporting a camera.
Head clog Build-up of oxide particles from videotape on to the video head, causing a reduction or total loss of picture during recording or playback.
Head gap The magnetic gap between the poles in tape recorder heads.
Headlamp Luminaire mounted on a camera.
Headset Headphones, sometimes with microphone attached.
Helical scan Method of recording where videotape is wound in a helix around the drum carrying the video heads. Method used in all VCRs.
High band See BVU.
High energy tape Tape with higher coercivity than ferric oxide and giving improved picture quality.
High key High luminance pictures, generally with low colour saturation.
House lights Working lights in a studio.
Howl-round A whistling effect caused by sound from a loudspeaker being picked-up by a microphone which feeds the sound directly back to the loudspeaker again.
Illumination A measure of the amount of light incident on a surface. It is measured in lux (lumens/m2) or foot-candles (lumens/ft2).
Infill Picture source placed within a foreground shape in another picture, using colour separation overlay.
Inlay A picture keying itself into another picture so that the former becomes the foreground in the latter picture, e.g. name captions over studio pictures.
Iris The variable diaphragm that controls the amount of light passing through a lens.
Jack Type of audio socket consisting of concentric contacts separated by, insulators.
Jack field Multiple rows of jacks (may also apply to rows of video sockets).
Jack plug Audio plug with two or three concentric contacts.
Jelly Gelatine or plastic translucent material used to diffuse or colour a light source.
Kelvin See Colour temperature
Key light The primary light that establishes the shape or form of an object.
Keying colour The colour providing the switching signal in colour separation overlay or chroma key
Kilowatt (kW) One thousand watts.
Lantern Studio lighting unit or luminaire.
Lead oxide vidicon A camera tube more usually known as a ‘plumbicon’, now superseded by CCD sensors.
Leader Standard length of film or videotape at the front of a programme to ident the programme, protect the beginning of the programme from damage, and enable machinery to run up to the correct speed before the start of the programme.
LED Light-emitting diode.
Leddicon Trade name for a lead oxide vidicon.
Lens hood Device attached to the front of a lens to minimise the possibility of lens flares.
Lift An electronic adjustment in camera or telecine channel (usually operated continuously for optimum picture equality), which moves all picture tones up or down the tonal scale. This is achieved by adjusting the video signal’s DC level relative to picture black level.
Light box An evenly illuminated ground glass screen, usually lit with fluorescent tubes. Used for viewing transparencies.
Lighting barrel Bar from which luminaries are suspended.
Lighting console Control unit for adjusting the brightness of individual lamps and memorising combinations of settings.
Lighting hoist Machinery for raising or lowering luminaires.
Lighting plot Plan of the lighting rig for a particular programme.
Lighting rig (1) An arrangement of luminaries for a particular programme. (2) The installed lighting in a studio, including luminaries, suspension and hoists.
Limiter Device for restricting the maximum amplitude of a vision or audio signal.
Line standard The number of lines making up the TV picture (625 in Europe, 525 in the USA and Japan).
Line-up (set-up) Check on the technical performance of equipment prior to broadcasting or recording.
Linear source A tungsten halogen strip light typically 119 mm long and 13 mm in diameter. Used in soft-light sources and cyc lights.
Lines (1) Scanning structure of a TV picture. (2) Circuit external to a centre booked through local BT operators. (3) Measure of the ability to resolve picture detail (a broadcast camera may have a resolution of 700 lines).
Lip mic Ribbon microphone used very close to the presenter’s mouth to exclude external sounds in noisy environments.
Low-angle dolly Camera mounting that enables the camera lens to go very close to the ground.
Low band Standard U-matic (3/4 in) recording, non-broadcast quality.
Low key Picture where the majority of tones are low luminance.
Lumen Unit of luminous flux or quantity of light emitted per second.
Luminaire Lighting unit or lantern.
Luminance Brightness part or monochrome part of a colour picture.
Lux Metric unit of illumination. 1 Lux = 1 Lumen/m2
M-format An integrated broadcast quality camera/recorder system using the VHS cassette size but not compatible with standard VHS.
Master First generation recording.
Master tape Final edited version of a videotaped programme.
Matte A mask, electronic or physical, used to obscure one picture and replace with another of the same size, dimension and position as the mask.
Matte generator See Colour synthesiser.
Megahertz (MHz) One million hertz.
Mic Microphone.
Mix A transition between one picture and another where one picture fades out whilst the other fades in.
Mixer Equipment devised to select and mix sound or vision sources individually or combined at any desired level.
Modulator An electronic facility used when television signals are to be distributed by coaxial cable over an appreciable distance, or made available at a number of monitoring points throughout an area. By superimposing the picture and sound signals on a radio frequency carrier, high quality results are achievable, viewed on conventional TV receivers.
Moiré Fine pattern on the screen caused by interference between picture elements and subcarrier.
Monitor Video display screen.
Monochrome (mono) Picture without colour information.
Multiplex A system of coding signals so that more than one can be carried on a single cable or radio frequency carrier such that each individual signal can be decoded at the receiving end.
Munsell system A system of colour notation, classifying a wide range of hues at varying degrees of saturation. The luminance of a surface is scaled in values from 10 (White) to 0 (Black). Surfaces with the same luminance value will appear the same tone (shade of grey) on a monochrome display.
Musa Professional video connector used mainly on vision distribution equipment and jack fields.
Music circuit (programme line) A high-grade sound line permitting wide-band, low-distortion transmission of audio signals, particularly between a remote source and its destination.
Mute Film or videotape without sound.
Newvicon Camera tube of a vidicon type but more sensitive than a vidicon.
Nicad battery Nickel cadmium battery.
Noise (1) Random dots on a picture (snow). (2) Background hiss, hum, etc. on sound.
Non-composite Vision signal minus synchronising pulses.
Non-sync Vision signals not synchronised with each other.
North light Large soft light source.
NTSC (National Television Systems Committee) Colour television system used in the USA, Canada and Japan.
Overlay See Colour separation overlay.
Overscan The normal domestic display of a picture whereby some of the linage is lost at the edge of the screen.
PA (1) Public address system. (2) Production assistant (person who assists director).
Paint Box Electronic painting device using a tablet and electronic stylus manufactured by Quantel.
PAL (Phase alternate line) Colour television system used in most of the countries of Western Europe.
Pan Rotation of a camera through a horizontal arc, thus ‘pan right’ and ‘pan left’ (Note: sometimes used incorrectly for tilt, hence ‘pan up’ and ‘pan down’.)
Panning head Device between camera and its mounting, enabling smooth panning and tilting of the camera.
Pantograph A spring-counterbalanced, collapsible, lighting suspension unit designed on the lazy-tongs principle. Units are available which allow the heights of luminaire of various weights to be adjusted easily over a wide range.
Passes Number of times a recorded videotape passed the video head to produce further recordings on a VT build-up.
Patch panel A system for connecting luminaires distributed about the studio with a selected series of supply circuits (usually incorporating dimmers/ switching/protection devices). It frequently takes the form of a plug and socket (jackfield) arrangement.
PDA See Pulse distribution amplifier.
Peak programme meter (PPM) Device for indicating peaks of sound levels.
Peak white Maximum level of a vision signal.
Pedestal Single manned studio camera mounting enabling smooth shot development including camera height.
Periscope Optical device for taking low-angle shots.
Perspective (sound) The illusion of distance of a sound source.
Perspective (vision) In pictorial terms, an illusion of depth and space created by the use of decor, lighting and lens-angle selection. It is essential for picture and sound to maintain related perspective to create a co-ordinated effect.
PFL See Pre-fade listen.
Phantom power DC power provided down the audio cable for electrostatic microphones.
Phase distortion Distortion arising when the relative phases of component parts of a complex wave are changed.
Playback (1) Replay of recorded material. (2) Replay of pre-recorded music for performers to sing or dance to.
Plumbicon Trade name for a lead oxide vidicon tube, now largely superseded by CCD sensors.
Portapak Battery-powered videotape machine.
Positioner Vision mixing facility for positioning wipes on the screen.
Post dub Recording of additional information on a sound track after the main recording has been completed.
Post-synchronise To attempt to add synchronised sound (e.g. dialogue or music) after the pictures have been shot.
PPM See Peak programme meter.
Pre-fade listen (PFL) Facility on sound mixers to enable sound sources to be checked before being faded up.
Pre-record Record part of a programme before the main recording.
Presence Boosting the mid-range frequencies (3–8 kHz) of an audio signal to improve subjective sound quality.
Preview (1) Advance showing of a programme. (2) Checking a picture before its use in a programme. (3) Band of switches on a vision mixer permitting advance selection of sources before putting them on transmission.
Producer The person responsible for the overall planning, financial control and artistic shape of a series of programmes.
Profile lamp Luminaire with focusing lens for projecting images on to a background.
Prop(s) Properties. Movable articles used for set dressing or as part of the action.
Public address (PA) In television studio operations, a feed of selected sources being reproduced by loudspeakers near a studio audience.
Pull focus Change the plane of focus in a scene to draw attention to a new point of interest.
Pulse distribution amplifier (PDA) Used for distributing the necessary pulses to camera and other vision equipment needing synchronisation.
Purity The correct rendition of a plain colour on a cathode ray tube.
Ql Quartz iodine lamp. See Quartz halogen.
Quadruplex recorder Professional videotape machine using 2-inch wide tape and orthogonal scanning, now completely superseded by helical scan machines. Some specialist companies are able to transfer historic recordings on this format.
Quartz halogen Lamp made of quartz glass and filled with halogen gas, used in most modern studio lights.
Raster The bright rectangular area formed on the screen of a television picture tube (by an unmodulated scanning beam tracking an interlaced line pattern on its phosphor surface).
Registration The combining of Red, Green and Blue camera images to obtain a single image.
Reverberation The prolongation of sound caused by repeated reflections from walls, floor, ceiling etc.
Reverberation time The time taken for the reverberant sound to decay through 60 dB.
Reverse talkback Talkback from a destination to the source, e.g. cameraman to director.
RGB Primary colours (red, green, blue) of television system.
Rostrum (1) Raised platform in the studio. (2) Flat bench for stills, animations or model work.
Rostrum camera Camera supported over a flat bench with calibrated control of panning, tracking, zooming and focus for stills, animations or model work.
Saticon Type of camera tube found in some studio and industrial cameras, now being superseded by CCD sensors.
Scanner (1) Mobile production vehicle. (2) Head assembly on a VTR.
Scene dock Storage area for scenery.
Script Rehearsal script only contains the actors’ lines (dialogue) and basic action (moves). A camera script also includes the operational, technical and staging information required for production treatment.
SECAM (Séquence Couleur avec Mémoire) Colour television system used mainly in France and USSR.
Sepmag Film using separate tracks for sound and picture that are synchronised.
Set-up See Line-up.
Shadow mask tube Type of display CRT used in colour television receivers and monitors.
Shot An uninterrupted picture from one camera.
Sibilance Sound distortion where some consonants, in particular S sounds, are over-emphasised.
Sidebands The band of frequencies either side of a carrier frequency, resulting from the process of modulation.
Slide scanner Device for producing television pictures from 35 mm slides.
Soft source A light source of large area which produces diffused illumination, and hence soft-edged shadows.
SPG See Sync pulse generator.
Split focus Focusing between two objects at different distances from the camera.
Split screen Two or more images displayed separately on different parts of a picture.
Spot (spotlight) Source of light giving well-defined shadows.
Spot effects Live sound effects.
Spring reverb Cheap echo device employing a spring with sound transducers.
Stage weight Heavy weight with hand grip used for restraining scene braces or items of scenery.
Standards conversion Conversion of one picture standard to another, e.g. 625 lines 50 Hz PAL to 525 lines 60 Hz NTSC, and vice versa.
Star filter Camera filter producing symmetrical starlike radiations from highlights, e.g. a light on jewellery.
Still frame Stationary picture from videotape machine or disc.
Storyboard Sequence of drawings to indicate how a story should be shot.
Super (superimpose) Mix two pictures together.
Switcher See Vision mixer.
Sync pulse generator (SPG) The heart of the TV studio that produces all the necessary pulses to drive the video equipment.
Synchroniser Digital store for a frame of video that may be read out at a different rate so that pictures can be synchronised with local pictures. May also be used as a basic timebase corrector.
Talkback Communications between production and technical staff.
Tally light ‘Camera live’ light.
TBC See Timebase corrector.
Tearing Ragged effect sometimes seen from chroma key switches when incorrectly set up.
Technical run Rehearsal of a complete programme usually in a rehearsal room for the technicians responsible for lighting, sound and cameras.
Telecine (TK) Machine for replaying film on TV.
Teleprompter Device usually fitted on the front of a camera to enable a performer to read the script whilst looking directly at the camera.
Termination The electrical load value required to match the output impedance of a piece of equipment, or a line.
Test card Studio caption specially designed to enable cameras, monitors and receivers to be lined up.
Throw focus Change focus from foreground to background.
Tie-line Interlinking sound or vision connection routed between technical areas.
Tilt To move a camera through a vertical arc. ‘Tilt up’ and ‘tilt down’ refer to the direction the front of the camera moves.
Timebase corrector (TBC) Device for eliminating instability in VTR playbacks to make them synchronous at the vision mixer.
Time code Digital signal which uniquely identifies frames, used for synchronising VTRs in editing and for logging purposes when preparing an edit.
TK See Telecine.
Tone Audio signal used for sound line-up, usually 1 kHz.
Track (1) Forward or backward movement of a camera. (2) Rails on which a camera can move (used mainly on location on uneven surfaces). (3) Ability of a zoom lens to remain in sharp focus on a subject while the zoom range is altered, i.e. change of shot size.
Track laying Synchronising a number of sound sources on different audio tracks with a picture.
Tracking line Imaginery line on which the camera moves.
Transceiver A combined transmitter and receiver.
Transcoder Device for converting from one colour system to another (but not line or field standards).
Transducer A device for converting one type of energy into another, e.g., loudspeaker converts electrical signals to sound waves.
Trimming tool A tool made of non-magnetic material used for adjusting the position of ferric cores inside coils (i.e. tuning them).
Tungsten Incandescent lamp used for domestic and house lighting having a nominal colour temperature.
Twin track Audio recording using half the width of quarter-inch tape.
TX Transmission.
U-Matic One of the commonest types of videocassette formats of industrial/ professional quality (becoming obsolete).
Underscan Reduced width and height of a television picture; used to ensure that all the picture information can be seen and not cut off at the edge of the screen as on domestic receivers, which are overscanned.
Upstage The acting area farthest away from the camera. Hence to walk ‘upstage’ is to walk away from the camera.
VCR Videocassette recorder.
VDU Visual display unit (usually for text or computer information).
Vectorscope Test equipment used for aligment of colour signals, giving a display of chrominance information in polar form.
VHS Domestic cassette format, now produced as standard play, long play and ‘super’ for semi-professional use.
Video disc Device for playing back vision and sound on a laser disc resembling an audio compact disc but larger.
Videotape recording Recording of audio and video signals on magnetic tape.
Vidicon Camera tube using a photo-resistive image sensor, now superseded by CCD sensors.
Viewfinder Small monitor on or adjacent to a camera.
Vignette (1) Mask placed in front of a camera to obscure part of a scene. (2) fault occuring with some lenses that reduces light sensitivity at the edges of the picture.
Vision mixer (switcher) (1) Electronic equipment for cutting and mixing picture and for producing a variety of special effects. (2) The person who operates the above equipment.
VT Videotape.
VT clock Videotape leader identifying programme and providing accurate cueing of VT replays.
VTR Videotape recorder generally of the open-reel type (cassette recorders are usually referred to as VCRs)
VU meter (volume unit) Audio meter giving mean audio levels.
Waveform TV signal displayed on an oscilloscope.
Whip pan Rapid pan of a camera.
White Balance Adjustment of camera controls, usually automatic, to ensure correct colour rendition of the camera.
Wild track Audio not synchronised to a picture.
Window The amount of jitter from a VTR that a timebase corrector can handle, usually measured as timing errors in multiples of line (e.g. 2-line window 8-line window).
Windshield A gauze or fabric shield fitted over a microphone to reduce the audible effects of wind, breath, etc.
Wipe Facility on a vision mixer to enable one picture to be replaced with another by a moving edge, or edges.
Wow Variation in speed of a recorder causing audible pitch changes between 1 and 15 per second.
Xenon lamp A discharge type projection lamp having a colour temperature of about 6500 K (the standard for projecting colour film).
XLR Professional audio connector using three pins for balanced or unbalanced audio signals.
Y Symbol used for luminance part of a television signal.
Zero level In audio engineering, a signal equivalent to a sine wave of r.m.s. value 0.775 V (the voltage developed across a resistance of 600 ohms when 1 mW is dissipated in it).
Zoom lens of variable focal length which enables the shot size to be changed over a continuous range, e.g. 14:1.