address track time code The address track is where time code is recorded on 3/4" cassette systems. (see timecode)

AGC Automatic gain control insures that the camera or recorder is getting a sufficient level by boosting or limiting the incoming video or audio signal signal

aliasing A corruption or distortion of an image, often the result of compression or undersampling (subsampling). Jagged edges on titles are a common form of aliasing; because a monitor recreates images using individual pixels, diagonal lines will appear stepped. Graphic applications offer an anti-aliasing feature, which conceals aliasing by shading and thereby softening the edges of these lines. Titles created by matte or luminance keys on video switchers are also anti-aliased. (see switchers)

algorithm A mathematical formula (which is then applied to perform a computer processes).

All Stop A key on edit controllers which terminates all actions on any controlled machine, be it in play or record mode. If an edit has been programmed and aborted by the All Stop button, no update will be recorded on the EDL.

alpha channel A grayscale channel used for keys. On the alpha channel, the image to be keyed is usually represented by white, so for example a title that is to be keyed over video will appear on an alpha channel as white letters on black. The black is transparent, so in the final image what will remain is only the title, filled with whatever source has been designated.

ambience Also called "room tone", ambience is the natural sound occuring in any location. You should always record a minimum of 30 seconds of ambient sound for each camera location. This way you will be able to cover a myriad of problems (audio dropping out, audio changing) that can arise when editing sound.

amplitude Technically, amplitude is the greatest value of a wave, but it is also commonly used to refer to volume or the strength of a signal.

analog An analog signal is a continuous signal, as opposed to a digital one, which is created by sampling of the original. When analog signals are copied, they result in a degradation of the signal; this is referred to as a "generational loss". Digital signals show no generational loss, as they are mathematically reproduced anew (from values of 0s and 1s) every time.

assemble mode A type of recording or editing. Assemble recording is basically the same as hitting play and record at the same time to put your deck into record mode; it results in a break in control track, and erases everything that was previously on your tape, laying down new control track, new video and audio, and new timecode if you have an internal or external timecode generator. An assemble edit makes an assemble recording beginning at your in point.

A mode assembly A method of online auto-assembly based on the record machine's in-time. The program is therefore assembled sequentially, so this is potentially the most time-consuming method, though often the most accurate. There is also potential for confusion here: even though the term is "auto-assembly", the program is NOT assemble edited--it is almost always done in insert mode, to allow for separate audio and video edits.

artifact A corruption or distortion of the original signal when it is reproduced

aspect ratio The relationship of width to height. The current aspect ratio of video is 4:3. HDTV has an aspect ration of 9:6.

ASCII American Standard Code for Information Interchange. ASCII assigns an 8-bit binary code to each letter which can then be read by any computer, enabling many different kinds of files to be shared.

asymmetrical compression A compression algorithm which needs a greater amount of processing power to compress information than to decompress it. (see also post-production)

auto assembly A function performed by advanced edit controllers which build audio and video edits as dictated by an EDL. (see also edit decision lists)

automatic gain control AGC insures that the camera or recorder is getting a sufficient level by boosting or limiting the incoming video or audio signal

auto transition Controls on a video switcher which set up the rate at which a dissolve, wipe or key will take place, and execute the command. (see also switchers)

B

back porch Part of the horizontal blanking portion of the video signal. The back porch extends from the end of the horizontal sync pulse (contained within the horizontal blanking) to the beginning of the next line of picture. Burst is located on the back porch.

backtime To compute a source or record machine's in point based on the out point and duration of the material to be inserted or laid down.

bandwidth The size of the conduit through which digital information is sent. The greater the bandwidth, the faster the information travels. The question of bandwidth is critical where video is concerned, as full-resolution, full speed NTSC video requires approximately 1M per second. HDTV will require even more. The availability of "video-on-demand" and convergence (the true melding of broadcast and internet) is dependent upon adequate bandwidth.

basic A "blacked" tape--that is, one having control track and most often, time code. This tape can then be used for insert editing. Though any synchronous (see sync) signal can be laid down as the basic, black is most often used, as it is visually least distracting and edits can be previewed or reviewed more easily.

bars and tone A standard reference signal used to insure that the audio and video levels recorded by the camera are accurately reproduced by the deck playing back the tape. Bars are normally recorded at the beginning of every tape, and professional cameras have the ability to generate bars. It's not always possible to have reference tone, in which case audio levels will need to be adjusted based on the actual recorded material. Bars should be viewed as a reference only--when editing, monitor video levels using a waveform monitor and vectorscope. (see also scopes)

beam splitter A prism within the camera that separates the light seen by the lens into red, blue and green wavelengths, which are then processed by the camera.

Beta, Betacam Sony 1/2' video format, and also the cassettes used. Also available using metal tape, (SP), and in digital format, which plays analog tapes as well.

Beta SP The SP stands for "superior performance". Similar to Beta, but uses metal tape, which is of a higher grade than ordinary Beta tape. Beta SP decks can play and record regular Beta tapes, but SP tapes cannot play or be recorded on regular Beta machines. (see also sample Beta SP deck)

bidirectional A type of microphone which picks up sound from two directions, front and back.

bin A term used in non-linear editing systems. "Bin" is an old film term--film editors would hang pieces of film from hooks. To keep the film from picking up dust and dirt on the floor, the hooks were suspended over canvas bins. (see also digital editing)

bit Short for "binary digit". A bit is the smallest piece of digital information, and has a value of either 0 or 1 (off or on).

bitmapped A pixel-by-pixel recreation. A bitmapped image stores color information about each individual pixel, and is therefore larger file-wise than a vector-based image, which uses a mathematical formula to recreate color information. While vector-based images result in smaller files, because they define areas of color, they are less successful at recreating subtle coloration, such as gradients.

black Also called setup or pedestal, black is the absence of luminance in a video signal. The correct black level is 7.5 IRE on a waveform monitor, which is an oscilloscope, commonly referred to as a scope. It's important to make sure your scope is calibrated, then you can adjust levels to the proper setting using a TBC, or time-base corrector. Raising the pedestal will make black areas of an image appear grey, and will also raise the overall luminance. While sometimes the black areas of an image may not appear dark enough even though they are set to the correct level, lowering the pedestal causes it to interfere with horizontal blanking and is technically unacceptable. If it were being broadcast, your signal could be pulled off the air.

black burst Black burst is a composite video signal containing horizontal and vertical synchronization information, burst, and pedestal. It is also called color black.

blanking There are two types of blanking, horizontal blanking and vertical blanking. One frame of NTSC video, which is the current standard, lasts for 1/30th of a second and is made up of 525 lines which are scanned, or "painted" with an electron beam across the back of the picture tube in two fields--one field for the odd-numbered lines, one field for the even-numbered lines (see interlacing. The beam, or "gun" travels left to right, and when the end of one line is reached, it turns off until it reaches the beginning of the next line. The period of time during which the beam is turned off is called the horizontal blanking interval. During this time, color burst information and horizonal sync pulses are sent. When all the lines of one field are painted, the electron beam turns off and travels to the top of the screen to begin the process of scanning the second field. This period of time that the beam is off is referred to as the vertical blanking. During this time equalizing pulses, which concern the field being scanned, and vertical sync pulses are sent, as well as other information (see interlacing). Blanking is created by the source of the original tape (a camera or a film-to-tape transfer) and increases slightly with each successive generation. Though normally invisible to the viewer, if a tape is down several generations, blanking may exceed legal limits (20 to 21.5 lines for vertical blanking and 10.3 to 11.4 microseconds for horizontal blanking).

B mode assembly Auto-assembly that records all edits from one playback source or reel, then moves on to another. Also called checkerboard assembly, as during the process the record tape will have some sections that have been recorded on, some sections that have not.

BNC A type of video connector used to connect input or output of a composite signal or the three component signals. A BNC connector is also sometimes used to connect output video from a source to a monitor. (see also cables and connectors)

boom A pole used to suspend a microphone, and for convenience, used to describe the mic itself.

B reel This is originally a film term. Because a transition requires two sources--a source you are dissolving from and a source you are dissolving to, the material you dissolve or wipe to needed to be on a separate reel, which is itself a film term. The "from" source was known as the A reel, the "to" source was known as the B reel. Non-linear editing systems or digital format systems have eliminated the need for actual B reels. However, an EDL will still reflect B reels if the option is selected. (see also preread)

breezeway In the horizontal blanking interval, the breezeway is the space between the end of the horizontal sync pulse and burst.

b roll A generic term for any footage apart from interview material. B roll is also sometimes used to describe a copy of a tape, made with identical time code to be used as a b reel.

bump To copy to another format. A half-inch tape can be bumped to 1 inch, a 3/4 inch cassette can be bumped to Beta, etc.

burned-in time code See window dub

burst. A color reference signal sent out during the horizontal blanking interval. Burst is required by receivers (TVs) to decode the color information in the video signal.

bus A group of buttons which on a video switcher represent various available inputs. When a button is pressed, it selects that source. (see also switchers)

BVB A type of edit preview which shows black up until the in- point of the edit, then the video (and/or audio) to be edited in, then black again.

C

camera original The tape on which the original material is shot. The first generation.

cans Slang for intercom headsets.

capacitor A capacitor is something that holds on to an electrical charge. Condenser microphones take acoustic energy, store it, and release it as electrical energy. (see also capacitor mics)

cardioid A microphone pickup pattern which is heart-shaped, sensitive to sound in front and to some extent to the sides, but not in back of the mic. Cardioid means "heart-shaped". see also pickup patterns)

CCU Camera control unit. This sets white, black, and color levels transmitted by the camera.

character generator An internal CG on a deck creates a visual readout of the time code which is playing or being recorded on the machine. More sophisticated CGs are used in post-production to create the titles identifying people on screen, and are capable of storing information and producing complicated effects. (see also the post-production suite)

CCD A charge-coupled device. An electronic pickup element that changes the light picked up by a camera lens into the electrical pulses of the video signal recorded by the camera or deck. Cameras using a charge-coupled device (or CCD) are known as chip cameras, because the CCD is a chip. (see also light into video)

checkerboard assembly Auto-assembly that records all edits from one playback source or reel, then moves on to another. Called checkerboard assembly because during the process the record tape will have some sections that have been recorded on, some sections that have not. Also called B mode assembly.

chroma, chrominance The red, green and blue (color) information of the video signal.

chroma key A key is an electronic hole cut into a picture which is filled by another video source, or, in the case of a self-key, by itself. A chroma key cuts a specific color out of the background picture, and the missing portions of the picture are replaced by video from another source. The classic example of a chroma key is the weatherperson standing in front of a map. He is really standing in front of a blue or green screen. The blue or green is cut out, and the map is keyed in. This effect is accomplished using a video switcher.

chroma subsampling A digital compression technique that reduces the file size of the material being digitized by reducing the amount of color information contained in the file. (see also compression)

clip 1. On non-linear edit systems a clip refers to a piece of digitized video and/or audio. 2. A control on a video switcher that adjusts the level at which the key will be cut in. 3. To limit: a video clip sets a maximum white level. An audio clip suppresses any audio above a certain threshold, compressing it to the level of the clip. This can result in distortion.

clipping Audio distortion, caused either by the use of a limiter or by excess volume, eliminating frequencies which should be present in the signal. Also used to describe a threshhold set for video level.

closed-captioning Text display of program audio made possible by encoded data transmitted during the vertical blanking interval, or VBI. Special equipment decodes the signal.

C mode assembly Auto-assembly that moves sequentially through any one playback tape before moving on to another playback tape. C mode assembly also results in a checkerboard on the record reel.

CMX A complex, online edit system developed by CBS and Memorex.

co-axial cable The type of cable used to carry video signals from machine to machine, and video and audio from cable TV.

codec Codec is short for "compression-decompression". It is the often proprietary mathematical formula various digital systems use to compress and decompress information during file transfer. (see also compression)

color burst Often simply referred to as "burst". A color reference signal sent out during the horizontal blanking interval.

color correction A post-production technique that can adjust the overall hue of an image, or the parts of the individual components on a video signal.

color framing In composite video, the phase relationship of the color reference signal, or burst, inverts every frame, so if one cuts to the same image, this results in a horizontal shift.

color temperature A measure of the intensity of a particular light, which determines how it is seen by the camera. Lights with a low color temperature appear red, because red is the low end of the spectrum; high color temperature lights appear blue. This is true in film recording as well. It is critical to white balance a video camera each time you begin shooting in a different location. This gives the camera a reference for white light (which is a combination of red, green and blue light) and insures that colors will appear true to reality on the tape. (see also white balance)

component The separation of the luminance (black and white) portion of the video signal from the chrominance (chroma or color) portion. A component signal is superior to a composite signal because of this separation--the information is carried from point to point via three separate cables (Y, R-Y, B-Y) as opposed to one, which is the case in composite video.

composite A composite video signal is one that contains both color (chrominance) and black and white (luminance) information. It is carried from point to point over a single cable.

compositing Layering. Compositing of images involves layering several different sources which result in a single image.

compression 1. A method of decreasing a digital file size to conserve transfer time or storage of the file. 2. The limiting of audio to a preset level.

condenser mic Also called a capacitor microphone. A kind of microphone that converts sound waves into an electrical charge, which is stored and released by the capacitor. The variations of acoustic energy result in variations of voltage, and therefore volume. Condenser mics require a separate power supply. (see also microphones)

constant A mathematical value, either a particular time code number or a duration (1 second, 30 seconds, etc.) which can be stored by various types of edit systems and entered whenever needed. A typical use of a constant would be the time code of a corporate logo which is used frequently throughout a program.

continuity The necessary maintenance of reality within a scene--if a window is open in one shot, it needs to be open in the next, for example--in order to not confuse the viewer.

contrast ratio The difference between the lightest and darkest portions of an image.

control room The area where the director and on-air staff coordinate a live broadcast. The control room always maintains headset intercom communication with the studio (where the action is taking place), but is separate, largely to prevent studio microphones from picking up technical instructions given to the studio personnel, and to avoid feedback.

control track Control track, also called a "frame pulse", is an electronic signal similar to sprocket holes on film--it provides for stable edits and playback. Any time you record onto videotape from a synchronous signal, you lay down control track. If you see noise (also called snow or hash) appearing at an edit point, you have broken control track.

convergence The marriage of television and the internet. Because video files are so large, unlimited or greatly increased bandwidth is the prerequisite of true convergence.

crackle Crackle is a popping or rustling in an audio signal. It can be the result of a bad cable or connector, or a dirty pot on a mixer. If you are working with a mixer, turn the various knobs connected to the channel on which you are experiencing the crackle. If this affects the crackle it is in all likelihood the reason for it, and can sometimes dislodge the dirt which may be causing it.

cross-pulse monitor A monitor that is capable of offsetting the video picture so the horizontal and vertical blanking intervals are center screen for easier viewing.

CRT Cathode ray tube. A computer screen or television is a cathode ray tube, which is coated on the back with light-sensitive phosphor. An electron beam sweeps across the back of this picture tube (see interlace scanning) and causes the phosphor to glow, resulting in the picture we see on the screen.

cut To instantaneously change from one video and/or source to another.

D

DAT Digital audio tape, or its recorder. Offers superior quality to analog audio.

decibel A unit of sound measurement abbreviated as dB. A VU (volume unit) meter shows a visual representation of audio being played or recorded, with a typical range from -20 to +3 dB.

deck A videocassette recorder.

demodulate An audio or video signal is encoded onto a portion of the radio frequency spectrum in order to be transmitted. A reciever, which is what a television set is, receives the signal and demodulates it--that is, reverses the process and converts the signal back into video and audio.

depth of field The shortest distance from the camera lens to the longest distance from it in which all objects remain in focus. Wide lenses (eg 35mm) have a greater depth of field than longer, or zoom lenses.

diaphragm Part of certain kinds of microphones, a diaphragm is a thin metal strip that vibrates in response to sound waves.

diffusion filter A filter used on a camera lens to soften light and lower contrast.

digital An analog signal is a continuous signal, occuring in nature, for example a sound wave. An analog recording is also continuous. A digital signal uses off and on pulses (in the form of 0s and 1s) to reproduce or record mathematical values representative of the original analog signal.

digital effects generator A post-production device that uses a computer to manipulate video images.

digitize To convert from an analog signal into a digital one, and bring that signal into a computer for editing or image manipulation.

director The person who literally calls the shots in television or film production.

direct output On non-linear editing systems direct output sends the processed digital signals out in the form of a component or composite video, and analog or digital audio.

dissolve A transition effect whereby one image is gradually replaced by another.

distribution amplifier Signals travelling over distances lose strength and can pick up interference (noise). Distribution amplifiers (DAs) boost the signal so that it will not need to be boosted at its destination, which would increase the signal-to-noise ratio.

D mode assembly Auto-assembly according to the record machine's in point, so similar to A mode. However, in D mode, any edit other than a cut is notated and executed at the end of the EDL.

Dolby NR™ A noise reduction system. If a tape is recorded with Dolby™ on, it must be edited with Dolby™ on, otherwise the sound quality will be inferior.

dolly A camera move that involves physically bringing the camera in closer to the object being recorded. In order that the dolly be smooth, tracks are often laid down and the camera is wheeled over them.

downstream Occuring later. A downstream key is one that has been set up after any other effects. Any downstream effect can be changed without altering the image upstream of it.

drop frame time code We say that video travels at 30 frames per second, but in reality it travels at 29.97 seconds. Over the course of one hour, this slight time discrepancy accumulates to 3.6 seconds, a sizable amount, which of course would be compounded x24 over the course of a single day. Drop frame time code drops two frames every minute except at 10-minute marks (10 minutes, 20 minutes, etc.) to account for this difference, resulting in one hour of videotape lasting exactly one hour, and accurate time-of-day code.

dropout A flaw in the ferrous oxide backing of videotape on which the signal is recorded, a dropout can be insignificant and barely visible, or large enough to break control track and cause the signal to lose stability. (see also the video signal)

dropout compensator A piece of equipment that conceals minor dropouts, by replacing the line containing the unacceptable signal with information from the scan line above it.

dub A copy. When a tape is dubbed, the copy is referred to as "down a generation".

dynamic motion control A control on various format machines that allows for freezing the action and slow or fast motion playback of video.

dynamic tracking A process that aids in the playing back of unstable video or video with problems in the control track by having the machine lock to the video frame line instead of to control track.

DVE This stands for digital video effects, and is piece of special effects equipment that can manipulate video.

E

effect A video transition other than a cut, or the digital manipulation of an image.

effects keys On certain edit systems, the keys that allow the editor to select the type of transition (cut, dissolve, wipe).

edit To lay down the content of a particular segment or program of material.

editors, edit systemsThere are two main types of systems--linear and non linear. Linear systems range from simple editors that create edit points based on control track to complex, time code based systems like CMX. Non linear systems are digital and random access. They have been in common use for only about 10 years, and though vary in regards to the quality they can output, are all sophisticated systems. The term editor also refers to the person running the edit system.

ENG Electronic news gathering.

equalization The altering of specific areas of audio frequency, either to correct error or to enhance sound.

equalizing pulse pulses sent during the vertical blanking interval regarding which field is being scanned.

E to E mode Electronics-to-electronics mode. On some machines, once a tape is inserted the image at that particular spot on the tape is displayed, even if the machine is in stop or pause mode. E to E mode allows you to see the signal going into the machine (the input), instead of the output, which is the material on the tape in the machine.

exit key A key on many editors that allows the operator to escape from current dialog.

F

feedback A kind of ricocheting of a signal, either audio or video, that occurs when the signal being sent out is picked up by another piece of equipment within the system and sent out again over it. Audio feedback can be painfully loud and is always irritating, video feedback is often used for "artistic" effect.

fiber optic A type of digital transmission cable, fiber optic uses light pulses to transmit data.

field 1/60th of a second of video, a field is one half of a frame, and is comprised of either the even numbered of the 525 lines of an interlaced scanned frame, or the odd numbered lines.

field dominance Edit systems can begin an edit on either field of a video frame, resulting in either field 1 or field 2 dominance.

fill 1. The source that is used to fill in the hole cut by a key. 2. A generic term for the light used to fill in shadows and give definition to a camera subject. (see also lighting)

fixed frame size In digital edit systems the complexity of a video frame determines how large the file needed to store it will be. Storage can be set at either a fixed frame size, which allots the same amount of storage for any given frame, or variable frame size, which adjusts according to the complexity of a particular frame. (see also compression)

flag, flagging 1. A bend in the edges of an image resulting from stretching of the videotape, either during recording or playback. If the bend goes to the right the record machine was at fault, to the left means the problem is the playback machine. (see also skew) 2. A flag is an attachment for a light or camera positioned to block light.

flood A soft, diffused light.

focal length The length of a lens relative to the kind of shot it produces. "Long" (focal length) lenses result in close ups, "short" lenses yield a wide-angle picture.

footcandle A unit of light measurement--the amount of light shed by a candle at a distance of 1 foot.

foregroundThe content of the frame or the action that takes place in it closer to the camera lens or viewer, as opposed to in the distance.

frame 1/30th of a second of video. A frame consists of two fields, which are composed by either the even-numbered or the odd-numbered lines of an interlaced scan.

frame synchronizer A piece of equipment that locks the sync signal of a video input source to the "house" sync. (see genlock) A frame synchronizer can also accept video that has a problem with sync and send it out locked to the rest of the system.

freeze frame A stopped action image, created either digitally on non-linear systems, or on an analog machine by keeping the heads scanning the same frame of video. There are additional methods for creating a freeze frame.

frequency The number of complete cycles per second of a sound wave. The frequency of a wave determines its pitch.

front porch The area of the horizontal blanking interval extending from the end of picture information to the beginning edge of sync. (see also video signal)

f-stop A number on a lens indicating the relative size of the iris and thereby the amount of light the lens allows in. A high f-stop number (f16, f32) lets in little light, a low number (f1.2) means the iris is wide open and lets in alot of light. A higher f-stop results in greater depth-of-field.

G

generation Generation refers to the relation of a particular tape to the original of that tape. "First generation" is the actual recorded tape, "2nd generation" is a copy of that, etc. The image quality of tapes down several generations will deteriorate, sometimes badly, as errors (some possibly present in the original) will be compounded. It is important to note however, that this is a consideration in analog recordings only--digital copies do not deteriorate in quality, as the information is recreated anew each time.

genlock Any time several sources (playback machines, cameras, special effects generators, etc.) are either broadcast or edited together, they need to be "locked" to each other, otherwise there will be shifts or breakup during editing or airing when switching from one source to another. Genlock is a system that locks the sync and burst from these various sources. (see also switchers)

GPI General purpose interface. An electronic pulse that triggers various pieces of equipment (DVE, switchers, etc.) to perform a preset function.

H

HDTV High definition television. Because HDTV boasts more than double the number of scan lines per frame, the resolution of this wide-screen, digital format is far superior to current NTSC broadcast. HDTV uses a technique called "progressive scanning" (as opposed to interlace) to trace the information across the screen.

headsThe head is the device which rolls across videotape and either lays down information (in record mode) or reads it (in playback mode). Older, 2" machines are referred to as "quads", meaning that there are four record heads in the apparatus. Cassette type decks, as well as 1' machines are "helical", where the head travels across the videotape at an angle. For this reason, helical is also referred to as "slant track". Early videotape was physically cut to make edits--this became impossible with the advent of slant track, but in time, using electronic pulses to cue the machine to go into edit mode (instead of physically editing the tape) was accepted by the professional community and helical scan became industry standard.

helical scan The method of recording and playing videotape whereby the record and play heads are at an angle to the path of the tape. All modern machines are helican scan type.

heterodyne A heterodyne signal is a naked signal, viewed before processing and correction by a time base corrector. While the image may appear fine to the eye, it is technically unsatisfactory and must be processed before the source can be input into a switcher or edited onto another tape.

Hi 8 An inexpensive tape format that has become very popular in recent years, especially now that a digital version is available. The biggest problem with Hi 8 tape is that, because it is so thin, it sheds easily, resulting in dropouts after only minimal use. It's a good idea if you shoot in Hi 8 to dub (copy) your originals (with slaved time code to another format, and work from the copies. Then you can prepare an EDL and auto assemble from your original.

high definition Having superior resolution, which is a result of increasing the number of scan lines. This is the "HD" in HDTV.

hiss Unwanted audio noise in a recording, hiss is extraneous high frequency audio. Extraneous low frequency noise is referred to as hum.

horizontal sync A pulse sent dring the horizontal blanking interval that coordinates the correct location and timing of the electron beam. It tells the beam to go back to the left side of the screen and begin tracing another line of picture. On a waveform monitor, horizontal sync appears as a -40 IRE pulse.

hue The tint, or shade of a color. The hue adjustment on a time base corrector shifts the hue of the entire image, making it overall more green, for example, or more magenta. When timing one piece of equipment with another, the hue of one image must be in correct relationship to the hue of the other--this is often referred to as "system phase".

hum Hum is unwanted low frequency audio noise in a recording, as opposed to hiss which is high-frequency. Hum is often caused by feedback.

I

in and out-point The frame on a source or record tape at which an edit is to begin or end.

in-frame edit Also called a "match-frame" edit. The type of edit that initiates a transition such as a wipe or dissolve, which involves 2 sources--a "from" and a "to". What is typically done is that you record the "from" up to or a little past the point in the action where you want the transition to begin. You then stop the machine, (updating your EDL and program your next edit (which is your dissolve or wipe) to begin at the exact frame where your previous edit ended. It is imperative that none of the parameters (video levels, etc.) on your "from" source change between the previous edit and the next, or this will be noticable. Assuming levels etc. stay the same, the edit will appear seamless. On certain systems you may see a horizontal shift at the point of the in-frame edit. This can be due to the equipment not being correctly timed, or it can be due to a temporary shift in where the playback machine locks to the horizontal blanking. Try the edit again to see if the problem clears up.

input The signal going into a camera or deck.

insert mode A type of recording or editing. In order for insert recording or editing to take place, it is necessary to have unbroken control track for the length of the desired recording. In insert mode you can choose which tracks to insert--video or audio or both. You can set an out-point for an edit, you can "pop" into and out of edit mode, and on some systems you can program separate in-points for video and audio.

interframe coding Part of MPEG compression. Each frame of video is not compressed independently; rather, certain frames are independently compressed, but the data contained in the frames in between is used to predict several subsequent frames which are then processed according to this prediction rather than upon the actual information of the frame. Interframe coding offers considerable storage benefits, but is not as accurate a method as intraframe coding. (see also compression)

interlacing, interlaced scanning One frame of NTSC video, which is the current standard, lasts for 1/30th of a second and is made up of 525 lines which are scanned, or "painted" with an electron beam across the back of the picture tube in two fields--one field for the odd-numbered lines, one field for the even-numbered lines. The beam, or "gun" travels left to right, and when the end of one line is reached, it turns off until it reaches the beginning of the next line (see blanking. When all the lines of one field are painted, the electron beam turns off and travels to the top of the screen to begin the process of scanning the second field. If the frame were not broken up into two fields, the first painted lines would begin to fade by the time the beam got around to painting the last ones, and our brains would perceive a flicker in the image. So the information is divided into two separate fields, which are then "interlaced" together. The phenomenon of "persistance of vision" allows us to see these individual fields and frames as continuous motion.

intraframe coding Part of the JPEG compression method whereby all the data necessary to display any individual frame is stored, and the display of that frame is not depending upon information from any previous or successive frames. (see interframe coding and compression)

iron oxide Videotape is a piece of mylar with an iron oxide backing. These metal particles become magnetized and store the video and audio information on the tape.

IRE The acronym forInstitute of Radio Engineers, IRE is also a standard signal measurement.

iris Analogous to the pupil of the human eye, the iris is an opening in a camera lens that opens or closes to let in or keep out light. (see also the camera)

J

JPEG The acronym for Joint Photographers Experts Group. JPEG compression is a lossy compression formula, which discards information about the frame being compressed. JPEG compression stores information about each particular frame compressed, so uses intraframe as opposed to interframe coding. (see also compression)

jump cut A cut that breaks continuity. An unintended jump cut can be confusing or jarring. However, jumps cuts are often used for artistic effect.

K

key frame In digital effects systems, a key frame signifies a change or the beginning of a change in the programmed effect. All computer programmed effects begin and end with a key frame, and there can be several key frames in between.

L

L cut Also called split edit, an L-cut is a cut in which audio precedes video, or vice-versa. Many editing systems are capable of programming L-cuts, and reflecting them in the EDL.

limiter An audio control that sets a volume threshold and suppresses all audio over that limit. Many record decks have a built-in limiter option.

linear, linear editing Travelling from one point to another in real time. Linear editing is sequential editing, meaning that, if a section of an edited piece is removed (rather than replaced) so that the overall time of the piece is affected, the entire piece must be re-edited from the beginning of the section that was removed until the end of the piece. (see also analog editing)

list management The method of preparing an EDL so that the edits reflected in it are accurate, or "clean", and a correct auto-assembly can be made from the EDL.

lock Stability. Machines that are locked are playing a stable signal. If there is an instability in the signal, the machine will not be able to lock. Machines check for horizontal, vertical, and control track lock before they will go into edit mode.

log A record regarding the visual (as opposed to the purely technical) information about a particular shot. Logging is a function of non-linear edit systems, and is the way that individual clips are identified to the editor (though not to the computer). Handwritten logs are often made by editors using linear systems, to guide them when they are looking for particular shots.

longitudinal time code (LTC)Time code is a visual labelling of each frame of video, displayed as hours:minutes:seconds:frames. There is more than one place to encode the signal. Longitudinal time code is time code recorded on one of the audio tracks.

lossless compression A method of compression that does not permanently discard any information in order to make the file smaller.

lossy compression A method of compression that, in order to make the file smaller, results in permanently irretrievable information.

lower third A common reference to the title identifying an on-camera speaker (or any title displayed at the bottom of the screen).

luminance The black and white information of the video signal. Luminance is also used to describe the light, or white level.

M

mark in/out A button on certain linear edit systems that allow one to put an in or an out point in "on the fly"--that is, as the tape is playing.

master Sometimes used interchangeably with "original", meaning the tape recorded by the camera, but more frequently used to describe the final edited product.

match cut A cut occuring at a precise point of action that is picked up at the same point of action, but from a different angle, or distance from the action.

match-frame edit Also called an "in-frame" edit. The type of edit that initiates a transition such as a wipe or dissolve, which involves 2 sources--a "from" and a "to". What is typically done is that you record the "from" up to or a little past the point in the action where you want the transition to begin. You then stop the machine, (updating your EDL and program your next edit (which is your dissolve or wipe) to begin at the exact frame where your previous edit ended. It is imperative that none of the parameters (video levels, etc.) on your "from" source change between the previous edit and the next, or this will be noticable. Assuming levels etc. stay the same, the edit will appear seamless. On certain systems you may see a horizontal shift at the point of the match-frame edit. This can be due to the equipment not being correctly timed, or it can be due to a temporary shift in where the playback machine locks to the horizontal blanking. Try the edit again to see if the problem clears up.

matte 1. A color filling the hole cut by a key. 2. A high-contrast image used to create a key. A matte key is a key filled with color generated by a switcher.

metal tape A type of videotape superior to standard ferrous-oxide backed tape. Metal tape is used in SP (for "superior performance") systems.

mixdown The process of combining audio from several different sources or tracks onto one track. Also called simply a "mix".

mixer An audio console, which is capable of equalizing and adjusting volume and direction. Most sophisticated edit systems route the source audio through a mixer rather than directly into the record machine; this way, the audio can be adjusted as needed.

modulate To alter an audio or video signal for the purpose of encoding it onto a radio frequency so it can be transmitted and then decoded back to its original signal.

MPEG Moving Picture Experts Group. A lossy compression method. MPEG uses both intraframe and interframe coding, and is an asymmetric compression method, meaning it requires more time to compress the image (store it digitally) than it does to play it back (decompress).

N

non-additive mix Normally in a dissolve, which a switcher sees as a video mix, each source can output only 50% of maximum video level so as not to exceed the acceptable luminance level. However, some switchers allow effects which mix two sources but do not limit the video level coming from one or the other. An example would be an effect that spotlights one area of the picture while darkening the rest. This is called a non-additive mix.

non-drop frame time code Non-drop frame time code is time code that does not drop any frames. As drop frame time code is used by networks that have to conform to strict time of day, any program not for broadcast does not need to use drop frame.

non-linear Often used interchangeably with the term random access, but the two have slightly different meanings. A non-linear system allows one to edit non-sequentially. One can remove portions from the middle of an edited segment, (affecting the overall time of the segment), without having to reedit from the edit point on. Any non-linear system is by nature random access, because it is digital, but random access refers to the computer's ability to call up any particular file at any time. So non-linear refers to what you DON'T have to do (cue up the playback machine to the exact spot on the tape you are looking for, among other things), while random access refers to what you CAN do (access any file instantaneously).

NTSC National Television Standards Committee, though sometimes sarcastically said to stand for "Never The Same Color". NTSC is the standard used in the United States and Canada, Japan and South America. It uses a rate of 29.97 (30) frames per second, and scans 525 lines per frame, while PAL (Phase Alternate Line, used in China, Britain and several European and Asian countries) and SECAM (Sequential Color With Memory, used in the Soviet Union and certain European and African countries) are based on a 25 frame per second rate and a scan of 625 lines per frame. There are other differences between the standards, which are not compatible. If you have NTSC video that you want to use on a PAL machine in Europe, for example, your video will need to be converted to PAL.>

Nyquist rate A formula applied to digital sampling. In order for information to be accurately recreated digitally, it must be sampled at least twice as fast as it can change. The Nyquist rate, also called the Nyquist limit, is equal to 1/2 of the highest frequency (number of times) of sampling for a particular signal.

O

online Post-production. An online room is a post-production room, which prepares the product for its final destination. (see offline & online)

on-the-fly While the machine is playing. You can "mark an in" or "out" on the fly, go into edit mode, even switch input sources on the fly while editing or on the air. (see sync mode editing)

open-ended edit A machine that is programmed with an "in-point" only on both the source and record machines.

original The camera or record master, the first recording (generation) of a particular signal.

oscilloscope Called a "scope" for short, oscilloscopes are used to monitor incoming and outgoing video. The luminance portion of the signal, as well as the blanking intervals are viewed with a waveform monitor. Chroma is viewed with the use of a vectorscope (though some color information can be seen on a waveform). (see also scopes)

out-point The termination point of an edit.

overmodulated Refers to audio. Recorded at too high a level and therefore distorted.

overrecord To record past the point of one's intended or presumed out-point in an edit. Often this is done to set the machine up for a match-frame edit, or because you're not really sure where you're going out of the material, or to lay down enough control track to continue with an assemble edit.

overscan A viewing option on monitors that allows you to see the picture as it will ultimately appear on a home television. Normally during production and editing the signal is viewed on "underscan, which allows you to see the edges of the video, blanking, etc.If there is a disturbance in the signal you can check to see whether this will appear on your ultimate picture by flipping to overscan. You can also check to make sure that titles are in the "title-safe" zone and will not be cut off on a home screen.

oxide The magnetic material on the back of videotape that carries the audio and video signal.

P

pan A camera move, from left to right or vice-versa, where the height of the camera doesn't change.

patch bay A board that allows you to direct or "patch" incoming and outgoing signals to different machines or locations.

pedestal 1. Also called setup or black, pedestal is the absence of luminance in a video signal. The correct pedestal level is 7.5 IRE on a waveform monitor, which is an oscilloscope, commonly referred to as a scope. It's important to make sure your scope is calibrated, then you can adjust levels to the proper setting using a TBC, or time-base corrector. Raising the pedestal will make black areas of an image appear grey, and will also raise the overall luminance. While sometimes the black areas of an image may not appear dark enough even though they are set to the correct level, lowering the pedestal causes it to interfere with horizontal blanking and is technically unacceptable. If it were being broadcast, your signal could be pulled off the air. 2. A pedestal shot is a camera move up or down a vertical axis. This type of move is almost impossible to do smoothly without some kind of pneumatic device.

phase 1. Often short for color phase, and refers to the overall redness or greenness of an image, (the hue or tint). If something is "out of phase" in this sense, the color is off. 2. Short for horizontal phase, or "h-phase", and refers to the horizontal blanking. 3. An out-of-phase audio signal is one in which the peaks and lows of sound waves cancel each other out, resulting in a loss of volume.

phosphor A light sensitive substance painted on the back of your television screen. An electron beam scans across it and activates red, green or blue "dots" which recreate the image being transmitted.

pick-up element A tube (see CRT) or a solid-state chip (see CCD) that converts light into a video signal. (see also the camera)

pixel Short for "picture element". A single dot, the smallest unit of the lines that recreate a bitmapped image on a television screen or computer monitor.

post-production This refers to editing, the adding of special effects, audio mixing or sweetening--all that is done to material after the stages of planning and shooting. (see also the post-production section.)

potentiometer Commonly called a "pot". A knob or lever that controls volume or direction (pan), etc. on an audio mixer.

preread A capability of certain digital edit systems that allows the record machine to dissolve from itself to a source, and thus eliminates the need for a "from" source, or "A reel".

preview To see what an edit will look like before actually performing the edit. Used only in linear editing systems, where performing the edit might erase previously recorded video or audio.

proc-amp A process-amplifier, which stabilizes sync and on certain machines, is used for setting hue and chroma level.

producer There are many different kinds of producers in video production. Generally, anyone with "producer" in his/her title will have some responsibility regarding content, as well as "how the job gets done". The director is ususally responsible for the look and style of a program, and if it is "live", for assuring that it is broadcast successfully.

Q

Quicktime The software which enables multimedia movies to play on a Macintosh computer.

R

random access Often used interchangeably with the term non-linear, but the two have slightly different meanings. Random access refers to the computer's ability to call up any particular file at any time. A non-linear system allows one to edit non-sequentially, and remove portions from the middle of an edited segment (affecting the overall time of the segment), without having to reedit from the edit point on. Any non-linear system is by nature random access, because it is digital, but non-linear refers to what you DON'T have to do (cue up the playback machine to the exact spot on the tape you are looking for, among other things), while random access refers to what you CAN do (access any file instantaneously).

RCA connector A type of connector used to carry a signal from certain types of cameras to certain machines, or from certain machines to other machines. (see also cables and connectors)

record inhibit A button or tab on a videotape which when removed will prevent the tape from being recorded onto. There is also a record inhibit switch within decks that prevent the deck from going into record mode.

regenerated time code Time code which is slaved to an external source (often time-of-day) and recreated anew, rather than simply copied from one tape to another, for example. There is also a "Regenerated/Preset" option on decks, which allows you to choose between externally regenerated time code or internally generated (from the deck itself) time code which you can preset to any specific hour:minute:second:frame value.

resolution Resolution is "pixels per inch". A higher number of pixels per inch results in a better quality image, but also a larger file. HDTV, by virtue of having approximately double the amount of scan lines of regular NTSC video, has higher resolution.

RF Radio Frequency, or the modulated video signal which can be sent out over radio waves to be received by a television set (receiver).

RGB Red, green, blue. A superior video signal used for sophisticated paint and graphics equipment. An RGB signal is similar to a component signal in that it separates color and luminance information, but it is actually of higher quality than component. It is converted to a component signal in order to be recorded by a videotape machine. (see also the video signal)

ringing Color "bleeding", often seen in titles, caused by the inability of NTSC resolution to handle the rapid changes of frequency in the color part of the signal.

room tone Also called "ambience", room tone is the natural sound occuring in any location. You should always record a minimum of 30 seconds of ambient sound for each camera location. This way you will be able to cover a myriad of problems (audio dropping out, audio changing) that can arise when editing sound.

rough cut A version of an edited piece or program that gives a general idea of what the program will look like, but which is not finalized in terms of content, overall length, effects and transitions, etc. Rough cuts are often thrown together so that any problems (technical or content) can be recognized and dealt with early on.

S

safe title Describes the area of the screen which identifying titles must not go beyond or else they will run the danger of not being seen in their entirety on a home television.

sampling The basis of digital recreation, sampling is taking the measurement of a signal at specific, predetermined intervals. The faster the sampling speed, the closer the resulting recreation will be to the original signal.

sampling theorem The rule that a signal must be measured (sampled) at least twice as fast as it can change, or else it will be inaccurately reproduced. (see Nyquist rate)

saturation The level of color in a signal, the color intensity.

scan line One horizontal sweep of the electron beam. One frame of NTSC video, which is the current standard, lasts for 1/30th of a second and is made up of 525 lines which are scanned, or "painted" with an electron beam across the back of the picture tube in two fields--one field for the odd-numbered lines, one field for the even-numbered lines. The beam, or "gun" travels left to right, and when the end of one line is reached, it turns off until it reaches the beginning of the next line. (see blanking) When all the lines of one field are painted, the electron beam turns off and travels to the top of the screen to begin the process of scanning the second field. If the frame were not broken up into two fields, the first painted lines would begin to fade by the time the beam got around to painting the last ones, and our brains would perceive a flicker in the image. So the information is divided into two separate fields, which are then "interlaced" together. The phenomenon of "persistance of vision" allows us to see these individual fields and frames as continuous motion.

scrubbing Scrubbing allows you to listen to your audio at any speed, with the pitch reflecting the given (lower than normal or higher than normal) speed. Scrubbing is frequently used during the editing process, to isolate audio or determine where it begins or ends.

SECAM Stands for "Sequential Color with Memory" (in French). Used in France and parts of Eastern Europe, SECAM is similar to PAL in that it scans at 25 frames per second. The two however, are not interchangeable.

select An old film term which refers to preferred shots. If a tape has ten takes of a particular shot, the "selects" would be the ones preferred by the editor and/or producer.

self-key A key that fills the hole cut by the key source with the same source.

sequence The term used by some non-linear edit systems to point to an edited segment (as opposed to individual clips).

servo A small light on the front of a deck that reflects the stability or instability of the machine during recording or playback. When the input signal is synchronous and the machine is in record mode, the servo light will be steadily lit. If there is a break in the signal, the light will flicker until the machine locks once again to the incoming signal. During playback, any break in control track or unsatisfactory tracking will cause the machine to lose lock, and the servo light will flicker until the playback signal is stable.

set in/out keys Buttons on certain linear edit systems that allow the editor to input a particular time code number as an in or out point.

setup 1. Also called pedestal or black, setup is the absence of luminance in a video signal. The correct setup level is 7.5 IRE on a waveform monitor, which is an oscilloscope, commonly referred to as a scope. It's important to make sure your scope is calibrated, then you can adjust levels to the proper setting using a TBC, or time-base corrector. Raising the setup will make black areas of an image appear grey, and will also raise the overall luminance. While sometimes the black areas of an image may not appear dark enough even though they are set to the correct level, lowering the pedestal causes it to interfere with horizontal blanking and is technically unacceptable. If it were being broadcast, your signal could be pulled off the air.

shuttle A variable speed control on certain decks that allow you to go much faster or slower than normal speed and still see the images on your tape.

signal-to-noise ratio The intensity of a clean audio or video signal compared to the extraneous interference that comes along with it. A high signal-to noise-ratio is desired; some noise can usually be filtered out. A low signal-to-noise ratio can result in an unacceptable signal.

skew Skew is the tension of the tape as it passes over the heads. On some older machines and home cassette players, skew is an adjustable control, but newer machines have eliminated it as it can cause the tape to stretch, which will result in flagging.

slate Identifies a particular scene. The clapper slate was used in film when it was necessary to have a visual mark to use to sync up separately recorded audio. The top of the clapper clapping down on the slate was that mark. Videotape records audio and video on the same piece of tape, so no such cue is needed. However, slates are still sometimes used for identification purposes.

slave Taking orders from some other piece of equipment. Source and record decks are slaved to a edit controller during an edit session; time code is slaved when it gets its numbers from an external source. (see regenerated time code)

slomo Slow-motion.

SMPTE Society of Motion Picture and Television Engineers. A group of industry standards, including SMPTE code, which lays time code on one of a tape's audio tracks.

snow Also called hash or noise (though noise has an additional meaning), snow is what you see if you turn on the television to a station that has stopped broadcasting but neglected to put up a slide of a flag waving or the like. Snow is just random garbage going out over the airwaves, and you hear it as well as see it. It is also what you get if you play a tape on which nothing has yet been recorded. Because there is no control track on the tape and therefore nothing to lock to, there is no picture.

source The tape or piece of equipment your material is coming from.

split edit Also called an L-cut, a split edit is a transition in which audio precedes video, or vice-versa. Many editing systems are capable of programming split edits, and reflecting them in the EDL.

star filter A type of filter that causes intense areas of light to sparkle and twinkle like stars.

storyboard A shot-by-shot visual representation of a sequence. A storyboard is frequently drawn by hand to convey the idea of a proposed commercial or program to a client. In digital editing systems, clips can be set to show a representative frame of each shot, and then laid out in sequence, thus creating a storyboard.

stripe To lay time code down on a tape for the purpose of being able to insert mode edit onto that tape.

subcarrier Kind of a container within a container, subcarrier is information encoded onto a frequency which is then encoded onto another frequency for delivery. In composite video, chroma information is encoded onto a signal which is then included in the luminance carrier signal.

submaster 1. A copy of an edited master, made in case anything should happen to it. 2. A tape or section of tape that has been edited or has had considerable work or compositing done to it that is not the final product, but is used as a source for the final product.

subsampling A technique of reducing what would otherwise be the necessary amount of information in order to create a samller digital file. Subsampling creates obvious aliasing and other errors, but can be used when a file does not need to accurately recreate its original, but only represent it. Subsampling is often employed in digital edit systems when material is digitized at a low resolution. This provides an enormous savings in file size and therefore storage. The material is unusable as a final product, but can be offlined and later redigitized at a higher resolution, or an EDL can be created from the offline.

S-VHS Super VHS. Metal (and therefore superior quality) VHS tape.

sweetening Refers to audio. Can be anything from adding sound effects, to correcting errors. Sweetening is done using very sophisticated equipment which edit rooms and even most post-production suites do not have.

switcher A device having many different input sources which is capable of selecting them and creating effects from them.

symmetrical compression A compression formula which needs the same amount of processing power to compress information as it does to decompress it.

sync, synchronous 1. Audio sync refers to sound matching the video it was recorded with, as for instance, lip sync. 2. In video, sync is an electronic pulse. The proper recording and playing back of the sync pulse(s) keep the picture from breaking up, drifting, or other errors. 3. Synchronous time code is time code that is locked to the beginning of each frame of video it is being laid down on. If it is not locked it will be useless for editing purposes. 4. Switcher input timing sync means that everything going into the switcher is in phase with it and locked to it, so effects will not shift or have other errors. (see genlock)

sync mode editing Rolling two or more sources at the same time and switching between them while editing. Often used in music videos, where there is alot of fast editing on a predictable beat. When the record machine is stopped, the EDL will update and reflect the edits made on the fly.

system phaseThe locking of the phase of various input sources' hue so that the colors of each source's image will display correctly when a switcher goes from one to another.

T

TBC or time-base corrector A time base corrector. Because the video image is created on a precise time schedule (the scanning of the lines, blanking intervals, etc., it must be recreated according to that precise timing, otherwise the picture will be unstable. A time base corrector insures that the playback of recorded material conforms to the correct timing, and that any errors arising from the recording are corrected. It combines several functions: it strips off the old sync and lays a new, clean sync signal; it has a dropout compensator to correct imperfections on the tape; it has controls to adjust video and color levels and phase so that the optimum image is displayed.

tearing A bleeding or shredding of color or white, often occuring in a key if the clip is not precisely set, or in areas of a picture that show high contrast coupled with extreme detail (for example, leaves against a bright sky.

tilt A move where the camera goes from something higher to something lower (tilt down) or vice-versa (tilt up) but where the camera itself does not move on a vertical axis.

time code Time code is a signal of hours:minutes:seconds:frames that is laid down as part of a video signal for the purposes of computerized editing. Time code can be recorded on an audio track (longitudinal time code, or LTC), on a separate track (address track TC, on 3/4" machines), or in the vertical blanking interval (VITC).

time code generator A piece of equipment that lays down time code.

timing The locking of one piece of equipment's signal to another's, a kind of "lining up" of the elements shared by various pieces of equipment so there is no breakup of the picture when moving from one source to another. Timing refers to sync, blanking and system phase.

timeline On non-linear edit systems, a graphical representation of the edited sequence.

title Also called "lower third(s)" because they usually appear toward the bottom of the screen, titles identify a speaker, date or location.

title camera A high-contrast (black and white) camera mounted on an animation stand. The output of the title camera is used as a switcher input, and the black and white is used as the source for a key.

tone A standard 0dB signal, usually accompanied by bars laid onto and played back on a tape for the purpose of setting and recreating correct audio level.

trackingThe adjustment of the tape being played back to the heads reading the information off the tape. Adjustments in tracking attempt to recreate the same relationship between the playback machine and the tape as existed between the recording machine and the tape.

transduction The changing of one form of energy into another form.

transition Going from one source of image or sound to another, either instantaneously, which is a cut, or by dissolve, which is a gradual replacement, or by wipe, which is a progressive substitution of one picture's pixels by another's (there is no such thing as an audio wipe).

transport keys The keys on certain edit systems that control the movement of the source and record machines--play, stop, fast forward, rewind.

trim A button on some edit systems that allows you to plus or minus a specified number of frames to your in or out point. In more sophisticated system, adjustment of the in or out point is made using a keyboard. Trim also refers to the act of plus or minusing frames from the edit in or out point.

U

user bits An area in the time code which can be recorded (and later viewed) with additional information if desired. User bits are not normally recorded--special equipment is required.

V

VBV On linear edit systems, a function which allows you to preview an insert edit by seeing the video which comes before the edit, black for the duration of the proposed edit, and the video following the edit.

VCR Video cassette recorder.

vector-based Using mathematical formulas to compute and recreate areas of color. Vector-based files are much smaller than those of bitmapped images, which recreate color based on the color information of individual pixels.

vectorscope A type of oscilloscope which displays the color portion of the video signal. (see also scopes)

vertical blanking One frame of NTSC video, which is the current standard, lasts for 1/30th of a second and is made up of 525 lines which are scanned, or "painted" with an electron beam across the back of the picture tube in two fields--one field for the odd-numbered lines, one field for the even-numbered lines (see interlacing. The beam, or "gun" travels left to right, and when the end of one line is reached, it turns off until it reaches the beginning of the next line. The period of time during which the beam is turned off is called the horizontal blanking interval. When all the lines of one field are painted, the electron beam turns off and travels to the top of the screen to begin the process of scanning the second field. This period of time that the beam is off is referred to as the vertical blanking interval, so vertical blanking is the top and bottom portion of the signal when no picture is being scanned. (see also blanking)

vertical interval time code Time code recorded during the vertical blanking interval.

VHS Video home system.

video level The amount of luminance, or white in the signal, measured in IRE.

VITC Vertical interval time code.

VTR Video tape recorder.

VU meter Volume unit meter. A meter that shows a readout of audio level.

VVV On linear edit systems, a function which allows you to preview an insert edit by seeing the video which comes before the edit, the video of the proposed edit, and the video following the edit.

W

whip An instability in an edit that occurs when the color framing the source and record of machines is mismatched.

white balance The focusing of a camera on a white object, and activating a control within the camera that registers that object as white, and adjusts the camera for black and red, green and blue accordingly.

window dub A copy of recorded material which shows a "burn-in" of the hours:minutes:seconds:frames time code signal.

wipe A wipe is a progressive substitution of one picture's pixels by another's (there is no such thing as an audio wipe). Wipes come on many shapes--box wipes, circle wipes, etc., and may be used either for keys or transitions.

X

Y

Z