AAC – Advanced Audio Coding. A digital audio compression standard providing very high sound quality at relatively low bit rates. The standard Audio codec often referred to as MPEG-4 Audio. With QuickTime being the most popular encoder for AAC audio. It is frequently found in QuickTime 6 movies and MP4 files. Sounds much better than MP3 at lower bitrates, recommended for use with 3ivx Video.
A-B roll – Videotape editing arrangement where scenes on tape are played alternately on VTRs A and B and recorded on VTR C. Typically, the final output recorded on CTR C contains some scenes from VTR A and some scenes from VTR B with transitions (cuts, mixes, wipes, etc.) between the scenes. A-B Roll Two video sources played simultaneously, to be mixed or cut between. A/B Edit – An editing technique in which the output is switched form one video source (A) to another (B).
A/B roll editing – Editing from two source VCRs to a third recording VCR. A switcher or mixer is used to provide effects such as dissolves.
ac – Alternating Current. Electrical current that changes polarity regularly and continually.
AC coupling – A method of coupling one circuit to another through a capacitor or transformer so as to transmit the varying (ac) characteristics of the signal while blocking the static (dc) characteristics. In some GVG distribution amplifiers, when the ac coupling mode is selected, a feedback loop maintains the output signal at an average dc level of 0 volts regardless of APL (Average Picture Level) or dc offset of the incoming signal.
AC-3 – 1. Audio Compression-3 is usually marketed as Dolby® Digital and used in DVD, HDTV, and many movie theaters. 2. Audio Codec 3, raw Dolby digital audio stream. Commonly 5.1 or 2.0 channel surround sound. Used in most cinemas and found on nearly all commercial DVDs muxed in .vob.
AC/DC coupling – May also be called simply dc coupling Coupling between circuits which accommodates the passing of both ac and dc signals.
AD – Assistant Director. An assistant director’s duties include tracking the progress of filming versus the production schedule, and preparing call sheets. A First Assistant Director is responsible for the preparation of the shooting schedule and script breakdown used to plan the shooting of a film or television show. The AD works directly with the Director to manage of the minute to minute operations on the set during the process of filming, as well as co-ordinating the necessary communication of details of future operations as the filming progresses. Other duties include tracking the progress of filming versus the production schedule, observing all rules related to union crafts, labor contracts and location agreements, maintaining safety on the working set, and working with the Unit Manager to keep operational costs within the budgeted plan. A Second Assistant Director is responsible for information distribution and reporting, cast notification and preparations during the shooting process, recording of all data relative to the working hours of the crew and cast, management of the background cast (atmosphere or “extras”), preparation of call sheets, production reports,and other documentation. When needed, the Second Assistant Director can assume the duties of the First Assistant Director on a temporary basis.
A/D converter – Analog-to-digital converter (ADC, A/D, A-to-D). A circuit that uses digital sampling to convert an analog signal into a digital representation of that signal. ADC Analog-to-digital converter.
ADO – Ampex Digital Optics. Trade name for digital effects system manufactured by Ampex.
ADPCM – Adaptive Pulse Code Modulation. 1. A compression scheme used by CD-I and CD-ROM XA formats. Used to interleave audio with data. 2. An audio compression algorithm for digital audio based on describing level differences between adjacent samples. 3. A means of transforming analog sound to low bit-rate signals with the help of a linear sampling algorithm.
ADR – Automated Dialogue Replacement, Dialogue Looping, Dialog Looping, Looping. The re-recording of dialogue by actors in a sound studio during post-production, usually performed to playback of edited picture in order to match lip movements on screen. ADR is frequently used to replace production track of poor quality (e.g., due to high levels of background noise) or to change the delivery or inflection of a line. ADR can also be used to insert new lines of dialogue which are conceived during editing, although such lines can only be placed against picture in which the face of the actor speaking is not visible.
ADR editing – Automated Dialogue Replacement Editing. The process of editing sound during Automatic Dialogue Replacement.
ADR Editor – Automatic Dialogue Replacement Editor, the person who performs ADR Editing.
ADRM – Automated Dialogue Replacement Mixer, ADR Mixer. The person who mixes the sound during Automated Dialogue Replacement.
ADSR – Attack/decay/sustain/release, the four segments of a common type of synthesizer envelope. The controls for these four parameters determine the duration (or in the case of sustain, the height) of the segments of the envelope. See envelope.
AES – Audio Engineering Society.
AES/EBU – Informal name for a digital audio standard established jointly by the AES and EBU organizations. The sampling frequencies for this standard varies depending on the format being used; the sampling frequency for D1 and D2 audio tracks is 48 kHz.
AFM – Audio Frequency Modulation recording. An audio signal is frequency-modulated and recorded on the video track together with a video signal, enabling multi-channel audio recording and better reproduction.
AFV – Audio follow video. (see below).
AGC – Automatic gain control. 1. Camcorder circuitry that adjusts incoming signal levels automatically, alleviating excessive image brightness and distortion of loud sound. 2. Circuitry used to ensure that output signals are maintained at constant levels in the face of widely varying input signal levels. AGC is typically used to maintain a constant video luminance level by boosting weak (low light) picture signals electronically. Some equipment include gain controls which are switchable between automatic and manual control. 3. Electronic circuit designed to keep signals at an acceptable level by amplifying signals that are too low or reducing signals that are too high.
AIFF – Apple’s Audio Interchange File Format, normally used for uncompressed PCM audio at various depths and sampling rates, or simpler audio codecs (ie MACE 6:1).
AIV – An acronym for “audio in video”. Digital audio can be transmitted either via a separate connection (AES/EBU) or embedded in the video signal, meaning that audio is sent over the same data connection as the video signal. See also AES/EBU and Embedded.
AM – Amplitude modulation is a process used for some radio (AM broadcast) and television video transmission. A low frequency (program) signal modulates (changes) the amplitude of a high frequency RF carrier signal causing it to deviate from its nominal base amplitude. The original program signal is recovered (demodulated) at the receiver. This system is extensively used in broadcast radio transmission because it is less prone to signal interference and retains most of the original signal quality. See Frequency Modulation.
AMPAS – 1. Academy of Motion Picture Arts and Sciences. 2. Academy of Motion Picture Arts and Sciences Awards – AMPAS awards, Oscars, Academy Awards. The term “Oscar” was coined by an anonymous person who remarked that the statue looked like their Uncle Oscar.
ANSI – American National Standards Institute.
asa – Exposure index or speed rating measures the film speed sensitivity to light.
ASCII – American Standard Code for Information Interchange. A standard code used extensively in data transmissions in the past, in which 128 letters, numerals, symbols, and special codes were each represented by a binary number.
ASF – Advanced Streaming Format. Microsoft’s second video format, principally designed for streaming.
ASIC – Application specific integrated circuit. An integrated circuit designed for special rather than general applications.
ATR – Audio tape recorder.
ATSC – Advanced Television Systems Committee (USA). A group whose charter is to develop voluntary national standards for high definition television. It is the organization that is defining the standard for high-definition television in the United States.
ATV – Amateur TeleVision. Specialized domain of ham radio, transmits standard TV signals on UHF radio bands.
AVCHD – Advanced Video Coding High Definition. A format using MPEG-4 AVC/H.264 compression originally made for consumer HD camcorders. AVCHD can be played on media players in computers, or burned onto DVD recordable media and played back on Blu-ray machines at 1920 x 1080 resolution.
AVI – stands for Audio Video Interleave and is one of the most common formats for audio/video data on the PC. Developed by Microsoft for use in their Windows PC architecture, the formal name for the AVI is Audio Video Interleave (Interleave because the video and audio are bound together in chunks). AVI is not a CODEC itself. It is a container or a “wrapper” which allows different CODECs to be placed inside for playback. Microsoft’s first video format. Header information is placed at the end of the file. Limited codec support. Spec has been hacked too many times, and is not fully supported.
AVID – Manufacturer of a popular non-linear editing system. Often used to refer to the system itself, as “AVID editor”. Competitors include Lightworks and Apple’s FinalCut Pro.
aaton code – In-camera keycode/timecode reader.
Abby Singer – The second-to-last shot of the day. Named after production manager Abby Singer, who would frequently call “last shot of the day” or “this shot, and just one more,” only to have the director ask for more takes. See also martini shot.
aberration – 1. Something that prevents light from being brought into sharp focus, disabling the formation of a clear image. 2. Lens flaw – the inability of a lens to reproduce an accurate, focused, sharp image. Aberration in simple lenses is sub-categorized into seven types: Astigmatism – lines in some directions are focused less sharply than lines in other directions; Chromatic aberration or Axial chromatic aberration – different wavelengths of light coming into focus in front of and behind the film plane, resulting in points of light exhibiting a rainbow-like halo and reduction in sharpness; Coma – the image of a point source of light cannot be brought into focus, but has instead a comet shape; Curvilinear distortion – distortion consisting of curved lines; Field curvature – the image is incorrectly curved; Lateral chromatic aberration also known as transverse chromatic aberration – variation in the magnification at the sides of a lens (this aberration type used to be termed “lateral color”); and Spherical aberration – variation in focal length of a lens from center to edge due to its spherical shape – generally all parts of the image, including its center. The effects of lens aberration usually increase with increases in aperture.
above-the-line expenses – The major expenses committed to before production begins, including story/rights/continuity (writing); salaries for producers, director, and cast; travel and living; and production fees (if the project is bought from an earlier company). Everything else falls under below-the-line expenses.
absolute uncertainty – The uncertainty in a measured quantity is due to inherent variations in the measurement process itself. The uncertainty in a result is due to the combined and accumulated effects of these measurement uncertainties that were used in the calculation of that result. When an uncertainty is expressed in the same units as the quantity itself it is called an absolute uncertainty. Uncertainty values are usually attached to the quoted value of an experimental measurement or result, one common format being: (quantity) ± (absolute uncertainty in that quantity). Compare: relative uncertainty.
absorption loss – In telecommunications, attenuation of the optical signal within the fiber optic transmission medium. Usually specified in terms of dB/km.
abrasion marks – scratches on film caused by dirt, emulsion pile ups, improper handling, and other film damage.
academy aperture – Projection aperture screen image aspect ration of approximately 1:37:1.
academy leader – Identification and timing countdown film leader designed to specifications of the Academy of Motion Picture Arts & Science, and placed at the head end of a print reel. The countdown cuing information is related to feet before the first picture start.
access copy – Also called distribution or reference copy. An access copy should provide easy access or review of the content of a less accessible preservation or intermediate copy. The access copy is often relatively low resolution and made available online. An access copy should be a widely supported format that is easy to playback. See Additional Description and NARA’s Internal Specifications.
accommodation – The ability of our eyes to refocus at a new point of interest. In normal vision, the processes of focusing on objects at different distances (accommodation) and convergence/divergence (the angle between the lines of sight of our eyes) are linked by muscle reflex. A change in one creates a complementary change in the other. However, watching a stereoscopic film or TV program requires the viewer to break the link between these different processes by accommodating at a fixed distance (the screen) while dynamically varying eye convergence and divergence (something we don’t do in life) to view objects at different stereoscopic distances.
accurate – Conforming closely to some standard. Having very small error of any kind. See: Uncertainty. Compare: precise.
acetate base film – Cellulose triacetate film is the material used for making film in the 20th century.
acetate film – Also called “safety film” because it was created as a non-flammable alternative to nitrate film stock. Includes cellulose diacetate, cellulose butyrate, cellulose propionate, and cellulose triacetate. Cellulose triacetate has been standard since the 1950s and is usually referred to as simply “acetate”. All acetate film is susceptible to vinegar syndrome. Acetate base film was replaced by polyester.
acetate magnetic tape base – Cellulose acetate was used as a tape substrate (base) in many early magnetic tapes from the 1940s until the mid 1960s. Acetate is susceptible to vinegar syndrome. Acetate magnetic tape bases were replaced by polyester.
achromatic – 1. Free from chromatic aberration. An achromatic lens is able to transmit light without separating it into colors. 2. Achromatic color is distinguished by differences in its lightness. It has no hue, like black, white and shades of gray.
acoustics – the science of sound wave behavior in air.
action – “Action” is called during filming to indicate the start of the current take. See also cut, speed, lock it down.
action safe area – The area of a television picture that is visible on consumer television sets.
action axis – Imaginary line drawn between two subjects or along a line of motion as an aid in maintaining continuity of screen direction. Sometimes referred to as the “180-degree rule.”
active picture area – The part of a TV picture that contains actual image information as opposed to sync or other data. Vertically the active picture area is 486 lines for NTSC and 576 lines for PAL. The inactive area is called blanking.
active video – The portion of a video signal that contains picture information.
actor, actress – A person who plays the role of a character. Historically, the term “actor” refered exclusively to males, but in modern times the term is used for both sexes.
acutance – A measure of the sharpness with which the film can produce the edge of an object.
adaptive – Able to adjust or react to a video condition or application, as an adaptive circuit. This term usually refers to filter circuits.
additional camera – or B Camera. An extra camera operator, often needed for complicated action sequences or stunts. Contrast with additional photography.
additional photography – Additional photographer, reshoots, reshooting, pickups. Focus group or studio reaction to some shots or scenes may be bad enough to convince the filmmakers to discard them. In some cases, actors are recalled and parts of the movie are refilmed. This is referred to as “Additional Photography”, “Reshoots”, or “Pickups”. Contrast with additional camera, pickups.
additive synthesis – A system for generating complex waveforms or sounds by combining basic waveforms or sampled sounds prior to further processing with filters and envelope shapers. Additive synthesis is typically used in wavetable synthesizers like the Wavestation.
ad-lib – Unrehearsed, spontaneous act of speaking, performing, or otherwise improvising on-camera activity without preparation.
administration metadata – This includes digital rights, encryption, user access, air date scheduling, and other business administration.
advance – 1. Of a composite print: the distance between a point on the soundtrack and the corresponding image. 2. Of payment: an amount given before receipt of services.
aftertouch – 1. A type of control data generated by pressing down on one or more keys on a synthesizer keyboard after they have reached and are resting on the keybed. See channel pressure, poly pressure. 2. A type of pressure controlled MIDI data determined by how hard you press a key or group of keys on a keyboard after the initial attack, and while the key is being held down. It is typically used to add expression to a performance.
agent – A person responsible for the professional business dealings of an actor, director, or other artist. An agent typically negotiates the contracts on behalf of the actor or director, and often has some part in selecting or recommending roles for their client.
agitation – Gentle movement of liquid photo-processing chemicals (developer, stop-bath, fixer) during processing of film or paper in order to achieve uniform results. Agitation is necessary to achieve uniformity in various chemical developing solutions.
air – To broadcast a signal.
Alan Smithee – The sole pseudonym that the Directors Guild of America allowed directors to use when they wish to remove their name from a film. The name has reportedly been retired by the Directors Guild of America, after 1997’s An Alan Smithee Film: Burn Hollywood Burn revealed the alias to the general public. It appears that project-specific pseudonyms are now used instead, selected on a case-by-case basis when the DGA agrees that a film has been taken away from a director and cut and/or altered to such an extreme extent that it completely deviates from that director’s original vision.
algorithmic composition – A type of composition in which the large outlines of the piece, or the procedures to be used in generating it, are determined by the human composer while some of the details, such as notes or rhythms, are created by a computer program using algorithmic processes.
aliasing – 1. Distortion in the video signal which may manifest itself in different ways, depending on the type of aliasing: Spectral aliasing is caused by interference between two frequencies, such as the luminance and chrominance frequencies or the chrominance and field scanning frequencies. It appears as moire or herringbone patterns, straight lines that become wavy, or rainbow colors. Spatial aliasing is distortion that occurs because of limitations in physical resolution of the scanning process. It appears, for example, as straight diagonal lines that become stairstepped or jagged. Temporal aliasing is distortion resulting from information lost between line or field scans. It appears, for example, when a video camera is focused
on a computer screen; the video output shows a flickering bar on the computer screen because of the lack of scan synchronization of the camera and the computer. 2. Undesirable video display effects caused by excessive high frequency video information. Three examples are: jaggies (that occurs in a digital image when not enough samples are taken to accurately represent straight lines and smooth transition between highly contrasted edges), or stair-stepping (effect seen along the edges of objects), stepped or jagged edges of angled lines, especially at the slanted edges of letters; and raster scan aliasing, e.g., twinkling or strobing effects on sharp horizontal lines; and temporal aliasing, e.g., rotating wagon wheel spokes apparently reversing direction. 3. Undesired frequencies that are produced when harmonic components within the audio signal being sampled by a digital recording device or generated within a digital sound source lie above the Nyquist frequency . Aliasing differs from some other types of noise in that its pitch changes radically when the pitch of the intended sound changes. See Nyquist frequency.
alignment – The adjustment of components in a system for optimum performance.
all inputs hostile – Measurement technique, particularly for crosstalk, using worst case conditions (typically, full chroma signal on all inputs other than the one under test).
all ones – A digital signal consisting of data that contains all logical ones. In telecommunications, a test signal consisting of 11111.
all-notes-off: A MIDI command, recognized by some but not all synthesizers and sound modules, that causes any notes that are currently sounding to be shut off. The panic button on a synth or sequencer usually transmits all-notes-off messages on all 16 MIDI channels.
alpha channel – A view of an image that represents the presence and degree of opacity of objects. The channel associated with each pixel determines the degree of opacity of that pixel using a grayscale range. In video production, the alpha channel is used to determine layer masking (mask channel).
alphanumeric – A display symbol set consisting of the twenty-six letters of the alphabet and the digits 0 through 9. Also called ‘alphameric’.
alternating current (AC) – an electric current that reverses its direction periodically.
alternate mark inversion (AMI) – In telecommunications, an encoding protocol where successive data 1’s are transmitted as alternate, equal positive and negative pulses, and data 0’s are sent as spaces, each of zero amplitude.
ambience – Generally thought of as the character or quality of some environment. In audio we specifically mean the acoustical (sonic) characteristics of a space, including everything from the size of the space to what type of sounds are a normal part of it. For example: a big auditorium may, as part of its sonic character, have a large HVAC (Heating, Ventilation, and Air Conditioning) system that runs, which provides a constant background noise level. Any noise existing or injected into a space Humans will of course be acted upon by the space based on things like size, shape, and the various surfaces that reflect sound; they have a great ability to discern a lot about an environment from these aural cues. As an experiment put up a microphone in some different rooms of your house or apartment and make recordings. Listen to them later at an exaggerated volume so you can really hear the ambient noise level as it is being acted upon by the room acoustics. You will most likely be able to identify each room by its sound.
ambient light – all light in a viewing room produced by sources other than the display.
ambient noise – sound that is extraneous to the intended , desired, intentional, audio; background noise.
ambient occlusion – Ambient occlusion is a shading method that is often used as a replacement to Global Illumination because it can be much faster to render and easier to control, but it’s not that accurate. It adds extra soft self-shadowing, which gives the image more realism. A common technique is to render the scene in normal way and then render out a separate Ambient Occlusion pass to make a final composite.
ambient sound – or ambience. Natural background audio representative of a given recording environment. On-camera dialog might be primary sound; traffic noise and refrigerator hum would be ambient.
Amiga – The video computer that created the desktop video revolution.
amp, ampere (A) – 1. Unit of measure of electrical current, equal to one volt sent through a resistance of one ohm. Also one watt divided by one volt. 2. A connector manufacturer.
amplified – Any electronic device used to increase the level or power of signals applied to it.
amplifier – 1. an electronic device for increasing the strength of electrical signals. 2. The magnitude of a signal in voltage or current. Frequently expressed in terms of peak, peak-to-peak, or RMS.
amplitude – 1. the strength of an electronic signal as measured by the height of its waveform. 2. The amount of a signal. Amplitude is measured by determining the amount of fluctuation in air pressure (of a sound), voltage (of an electrical signal), or numerical data (in a digital application). When the signal is in the audio range, amplitude is perceived as loudness.
amplitude modulation (AM) – A method of imposing information on a carrier signal, such as a sine wave, by varying its amplitude.
anaglyph – A type of stereoscopy in which the two pictures are individually coloured and then superimposed as a single image rather than two separate images. Each eye sees only the required image through the use of coloured filters (e.g. red and green or red and ‘cyan’ (similar to blue)). Anaglyph glasses have been popular over the years for viewing 3D comics and some 3D films (particularly on VHS and DVD). Although Anaglyph itself has fallen out of favour for quality Stereo work there is modern work going on with other somewhat anaglyph like colour based systems (e.g. Trioviz or ColorCode-3D).
analog – 1. An electrical signal using continuously varying electrical voltages. Analog video that is copied or edited several generations suffers from generation loss and is subject to degradation due to noise and distortion. 2. The term analogue simply means like or similar. Traditional recording media have been analogue (magnetic recording tape and vinyl records). In analogue, the positive and negative aspects of a sound wave are converted via a transducer (microphone), to an A.C voltage. 3. Analog video and audio emit a steady wave of magnetic patterns that are interpreted as video and audio to be transferred to magnetic tape for viewing. 4. a method of transmitting information by a continuous but varying signal. 5. A signal that varies continuously over a range of amplitudes. A digital signal by contrast has only two values, representing 1 or 0. 6. Capable of exhibiting continuous fluctuations. In an analog audio system, fluctuations in voltage correspond in a one-to-one fashion with (that is, are analogous to) the fluctuations in air pressure at the audio input or output. In an analog synthesizer, such parameters as oscillator pitch and LFO speed are typically controlled by analog control voltages rather than by digital data, and the audio signal is also an analog voltage. Compare with digital. 7. a reproduction of something in another form. For synthesizers, this refers to the electrical voltages generated. They are analogs of the pressure waves that will eventually come out at the speaker as sound. These electrical signals are generated by an oscillator. Other electrical components can shape (envelope) and color (filter) the signal. The signal is prone to distortions from to the design and/or limitations of the electrical components used, which we may perceive as a warm and more natural sound than a digitally generated equivalent. Any synthesizer, new or old, that uses voltage controlled oscillators (VCOs) can be considered analog. 8. An adjective describing any signal that varies continuously as opposed to a digital signal, which contains discrete levels. A system or device which operates primarily on analog signals. The human nervous system is analog; it conveys analog ‘information’. It is not digital. The human brain is, therefore, also not digital.
analog component – Another name for component video, such as RGB or Y, R-Y, B-Y as opposed to digital component video.
analog-to-digital (A/D) converter (ADC) – A device that changes the continuous fluctuations in voltage from an analog device (such as a microphone) into digital information that can be stored or processed in a sampler, digital signal processor, or digital recording device.
anamorphic – Anamorphic filming technique was developed to make widescreen movies using 4:3 film. An anamorphic lens distorts the image picked up by the camera before it reaches the film. By using a similar lens when projecting the film back on screen, the correct, intended aspect ratio is restored.
anamorphic cinemascope – An optical system which has different magnifications in the vertical and horizontal dimensions of the picture. See also aspect ratio, contrast with spherical. Cinemascope is a tradename of an anamorphic technique.
anamorphic lens – A camera lens that produces a squeezed image on the film. When the film is projected using the proper lens reverses the effect and the image spreads out horizontally to create a wide-screen picture.
anamorphic release print – Print where the image is compressed horizontally. This print is designed to be viewed on a wide screen projection.
anamorphic widescreen – 16:9 Enhanced DVD mastering process whereby a film source with an aspect ratio greater than 4:3 (usually also greater than or equal to 16:9) is transferred to the DVD video master in such a way that the picture is vertically stretched by a factor of about 1.33 (e.g. if the picture had an aspect ratio of 16:9, it now has one of 4:3). The idea is to use as much resolution of the video master as possible so widescreen pictures use the 4:3 frame optimally, gaining another 33% of vertical resolution and looking markedly sharper. When playing a DVD with anamorphic widescreen the display (16:9 capable TV or projector and screen) has to vertically squeeze the picture by a factor of 0.75 so a circle is still a circle. If the display cannot do this the DVD player will do the squeezing and add black bars on the top and bottom of the picture. In that case the additional 33% resolution are not available.
angle – Field of view (fov) in degrees. 30° corresponds to the normal lens of 35mm still camera.
answer print – 1. The first print made from a negative. This is a timed print that has been designed to determine whether other color changes are needed before making release prints. 2. The first film print combining picture and sound in release form offered by the film processing laboratory to the producer for acceptance.
angularly reflective screen – a screen that reflects light back to the viewer at a complementary angle.
animatic – 1. Simple animation consisting of art work designed to be used as a video tape storyboard. Most commonly used for test commercials. 2. A more advanced storyboard using proxy models to rough out basic animation and camera shots. (Film industry term.)
animation – 1. Visual special effect whereby still progressive images displayed in rapid succession creates the illusion of movement. 2. The process of creating the illusion of motion by creating individual frames, as opposed to filming naturally-occurring action at a regular frame rate. See also computer generated animation, claymation, time lapse. Contrast with motion capture, rotoscoping. 3. The process of developing the actions (poses, timing, motion) of objects. Animation methods include key-frame animation, path animation, non-linear character animation, and motion capture animation. Animations are sequences of frames. 4. Usually found in .movs. Nearly uncompressed, used for exporting to a high quality source (such as animation) from QuickTime.
anime – A style of animated movie which had its roots in the comic books of Japan. Animation enjoys an immense variety of subject matter and audiences in Japan. Outside of Japan, “Anime” is often used to describe only the adult oriented science fiction and fantasy entries in the field.
answer print – The first graded print of a film that combines sound and picture, which is created for the client to view and approve before printing the rest of the copies of the film.
anti-aliasing – 1. The process of electronically reducing aliasing, especially letters and genlocked graphic elements. 2. sampling methods for avoiding the unwanted visual effects or artefacts caused by limited display resolution. These aliasing effects include ‘jaggies’(the jagged edges from letters or graphic elements such as titles and 3D objects, and stair-casing along diagonal lines), moiré effects, and temporal aliasing (strobing) in animated scenes. 3. A group of methods used to avoid image resolution artefacts, such as jagged edges on high-contrast contours. Anti-aliasing is accomplished by interpolating between the colours of adjacent pixels using sub-pixel techniques.
aperture – 1. An adjustable opening in a lens which, like the iris in the human eye, controls the amount of light entering a camera. The size of the aperture is controlled by the iris adjustment and is measured in f-stops. A smaller f-stop number corresponds to a larger opening which passes more light. F-stop examples are F2, F2.8, F4, F5.6, F8, F11. F-stops are logarithmic. Each stop admits 100% more light than the previous one. 2. (F/Number, F-Stop, Effect Aperture, Relative Aperture) A measure of the width of the opening allowing light to enter a camera. The apparent diameter of a lens viewed from the position of the object against a diffusely illuminated background is called the “effect aperture”. The ratio of focal length of a lens to its “effective aperture” for an object located at infinity is called the “relative aperture”, or “f/number”. Larger apertures allow more light to enter a camera, hence darker scenes can be recorded. Conversely, smaller apertures allow less light to enter, but have the advantage of creating a large depth of field. 3. an opening in a lens regulating the amount of light passing through the lens to the imager. See also shutter speed.
aperture preview – Controlled by a button or switch on some cameras, this feature permits you to look at the scene in the viewfinder with the aperture stopped down to the opening you intend to use when taking the picture. It is a handy aid in checking the effect of depth of field – i.e. what will be in focus.
aperture priority – Also called Aperture Value or AV. A function or shooting mode of a semi-automatic camera that permits the photographer to preset the aperture and allow the camera to automatically determine the correct shutter speed. What does that mean? You select the aperture setting you want and the camera then automatically calculates the appropriate corresponding shutter speed for proper exposure. It’s like a fully-automatic camera except you control the size of the aperture.
apochromatic – often shortened to “apo”, it means corrected for spherical and chromatic aberration. Lenses that are apochromatic cause all visible light wavelengths to focus on the sensor or film plane. Lenses that are not corrected for chromatic aberration tend to focus red, green and blue wavelengths on different planes.
append mode – In video devices capable of creating key frame effects, a mode that permits new key frames to be added to an existing key frame effect to make the effect longer.
armorer – A person who is responsible for weapons on the set of a movie or television show. Duties include providing the correct weapons to suit the era and style of the film, advising the director on use of weapons, choosing the correct blanks, creating a safe set for the use of said weapons, teaching actors about handling and using weapons, making sure use of all weapons is properly licensed, and ensuring the safety of everyone on the set while weapons are in use.
arpeggiator – A device that steps from note to note for whichever keys are pressed (or latched) in a preset or random pattern.
Art Department – The section of a production’s crew concerned with visual artistry. Working under the supervision of the production designer and/or art director, the art department is responsible for arranging the overall “look” of the film (i.e. modern/high-tech, rustic, futuristic, etc.) as desired by the director. Individual positions within in this department include: production designer, production buyer, special effects supervisor, draftsman, art director, assistant art director, set decorator, set dresser, property master, leadman, swing gang, and property assistant.
Art Director – The person who oversees the artists and craftspeople who build the sets. See also production designer, set designer, set director, leadman, and swing gang.
artifact(s) – 1. Sometimes spelled artefact(s) – Picture degradations that occur as a result of image-processing tasks, such as compressing an image which can result in an increase in digital “noise”. 2. A visual defect in an image caused by limitations or the malfunction of imaging equipment. See also motion artifact, contrast with cinch marks. 3. small disturbances that affect the quality of a signal. 4. any error in the perception or representation of any visual or aural information introduced by the involved equipment. Image artifacts appear as deviations from the original in the delivered image in video streaming systems.
archive – Off-line storage of video/audio onto back-up tapes, flash drives, optical disks, etc.
Articulation Artist – A person who takes an artist’s designs and builds them in a computer, so that animators can manipulate the figures to tell the story of the film.
artificial light – Man-made illumination not limited to “indoor” variety: fluorescent bulbs, jack-o’-lanterns, a car’s headlights. Has lower color temperature than natural light, and thus more reddish qualities. See: color temperature, natural light.
aspect ratio – 1. Proportional height and width of picture on screen. Current standard for conventional receiver or monitor is three by four (3:4); 3:5 for HDTV. 2. A measure of the relative sizes of the horizontal and vertical components of an image. “Academy Ratio” is 1.33:1. See also anamorphic. 3. Displays commonly have a 4:3 or 16:9 aspect ratio. Program material may have other aspect ratios such as 2.35:1, resulting in it being “letterboxed” on the display. 4. the ratio of image width to image height is widescreen or standard. This term is used to describe an image on a TV or movie theater screen, and is defined as the width of the image divided by the height. In the case of a standard TV with a full-screen image, it is 4:3 or 1.33:1 (once the mathematical division is calculated). Movie theater images are usually 1.85:1 or 2.35:1, sometimes called “widescreen” or “letterbox.” When the widescreen images are shown on a regular TV in their original aspect ratio, they leave a blank area at the top and bottom of the screen. 5. The proportions of an image expressed as the ratio between the horizontal and vertical dimensions. Because pixels are not necessarily proportional, the aspect ratio is independent of the number of pixels in the X and Y directions. For example, both NTSC and PAL television screens are 4 x 3 (aspect ratio 1.33). However, a CCIR601 NTSC image is 720 x 486 pixels, while a PAL image is 720 x 576 pixels. 6. 35mm film has an aspect ratio of 3:2 (or 1.5:1). Also applies to computer and television screens, image sensors and photographic prints. Computer monitors typically have an aspect ratio of 4:3, as do most digital cameras.
aspheric (aspherical) lens -A lens element that changes shape across its surface as opposed to one having a smooth continuous arc. Generally, an aspherical lens deviates slightly from an exactly spherical shape, and is relatively free from aberrations. Light rays are bent more at the edges of a conventional spherical lens than they are at the center, causing them to come into focus before the film plane or sensor plane. A lens made with aspherical elements focuses all the light rays passing through it on the film/sensor plane.
assemble edit (assemble mode) – 1. An editing mode that replaces all signals on the record tape (video, audio, control, and time code tracks) with new signals. 2. Also called ‘assembly edit’. Assembly edits cannot be used for editing because since they erase the control track portion of the video tape. (See also Insert Edit). 3. Building a videotape in which a series of clips are placed in order, one after another.
asynchronous – Lacking synchronization. In video, a signal is asynchronous when its timing differs from that of the system reference signal. A foreign video signal is asynchronous before it is treated by a local frame synchronizer.
Assistants – may be permitted by the editor to do some creative work, such as commenting on the editor’s work; cutting temporary (“temp”) sound effects and music into the track; and sometimes even editing scenes. After picture lock, the Assistant oversees the creation of optical effects such as fades, dissolves, etc. and cuts them into the work-print; continues to work with the sound department as necessary; and in some cases oversees the final stages of post-production, all the way through sound mix, negative conforming, and the production of final prints. The assistant editor chain of command consists of the First Assistant Editor(s), who bears the most responsibility for the smooth performance of the assistant team; the Second Assistant Editor(s); and the Apprentice Editor(s).
Assistant Art Director – An assistant to the Art Director.
Assistant Camera – A member of the camera crew who assists the camera operator. This person is responsible for the maintenance and care of the camera, as well as preparing dope sheets. In smaller camera crews, they may also perform the duties of clapper-loader and/or a focus puller. See also additional camera.
Assistant Film Editor – Editing room crew member responsible for providing any and all required logistical assistance to the editor(s). Duties vary, depending on whether the assistant is working with a picture or sound editor and whether the show is being edited on film or on a non-linear editing system. On a film-edited show, assistant picture editors will, during production: liase with the film lab and sound transfer facility regarding the processing of dailies; leader, sync and edgecode the dailies rolls; coordinate and take notes during dailies screenings; organize and maintain camera reports, sound reports, script notes, and lined script pages from the set, as well as lab reports and sound transfer reports; log all dailies footage; and reorganize footage for editing, if necessary. Ongoing, and during post-production, they will: reconstitute trims; locate and pull trims requested by the editor; check sync, clean, measure, re-splice, and add change-over marks to cut reels;coordinate screenings of cut work; take notes during screenings. Once the sound department begins work, the assistants produce change sheets detailing each day’s changes to the workprint and production track and send them, along with any necessary duplicate trims, to the sound department.
Assistant Production Co-ordinator – An Assistant to the Production Co-ordinator. See also Production Secretary.
Associate Producer – An individual who performs a limited number of producing functions delegated to her/him by a producer, under the direct supervision and control of that producer. The term may also refer to a person who would qualify as an executive producer of a project, but for the fact that (s)he acts on behalf of a production company which is subordinate to another one on that project. See also co-producer and line producer.
asymmetry – The relationship and position of I3 and I11 can be expressed in terms of asymmetry. This represents the ratio of pit to land length and can indicate the size of the pits on a Compact Disc. Positive asymmetry indicates the pits are longer than the lands. Red Book specifies an asymmetry of negative 20% to positive 20%. See also Red Book.
atmosphere – In rendering, the environment that surrounds the objects in a scene. For example, the simulation of fine particles (fog, smoke, or dust) in the air. When an object is photographed in the real world, it is usually within an atmosphere (for example, air) and can be surrounded by other background objects.
attack – The first part of the sound of a note. In a synthesizer envelope, the attack segment is the segment during which the envelope rises from its initial value (usually zero) to the attack level (often the maximum level for the envelope) at a rate determined by the attack time parameter.
attenuate – to reduce the amplitude (strength) of a signal or current.
attenuator – A potentiometer (pot) that is used to lower the amplitude of the signal passing through it. The amplitude can usually be set to any value between full (no attenuation) and zero (infinite attenuation). Pots can be either rotary or linear (sliders), and can be either hardware or “virtual sliders” on a computer screen.
attenuation – The decrease in amplitude of a signal.
attenuator – A circuit that provides reduction of the amplitude of an electrical signal without introducing appreciable phase or frequency distortion.
audio bandwidth – The range of audio* frequencies which directly influence the fidelity of a sound. The higher the audio bandwidth, the better the sound fidelity. The highest practical frequency which the human ear can normally hear is 20 kHz. An audio amplifier which processes all frequencies.
audio bridge – In telecommunications, a device that mixes multiple audio inputs and feeds back composite audio to each stations, minus that station’s input. Also known as a mix-minus audio system.
audio clip – In a non-linear editing environment a clip indicates data of either video or audio that has been clipped out (copied) from a larger environment such as a reel or a video tape.
audio crosspoint module – Circuit board containing crosspoints for audio signal switching.
audio distribution amplifier (audio DA) – A device used to replicate an audio signal, typically providing 6 outputs, each of which is identical to the input signal.
audio dropout – Audio dropout is a brief reduction or loss of signal that occurs during playback, and it can be found in both analog and digital audio tape sources. Dropout is the result of a defect in the carrier or playback mechanism. Digital Audio Tape (DAT) is particularly susceptible to dropout. Digital audio dropout is caused by a non-uniform magnetic surface, or a malfunctioning tape deck. However, because the magnetically recorded information is in binary code, it results in a momentary loss of data and can produce a loud transient click or worse, muted audio, if the error correction scheme in the playback equipment cannot correct the error. Digital dropouts can be very difficult to eliminate. If you encounter a digital recording with dropout, try cleaning the playback head and re-transferring, or try re-transferring on a different deck. If the deck the tape was originally recorded on is still available and in good working order, try using it instead. Bear in mind that the dropout may have been recorded into the source; in these cases, switching decks or cleaning the heads will not solve the problem. Should dropouts persist, production or access copies of files can be remediated using software tools that use digital signal processing (DSP) techniques to resynthesize gaps in audio content.
audio dub – Result of recording over prerecorded videotape soundtrack, or a portion, without affecting prerecorded images.
audio frequency modulation (AFM) – Method of recording hi-fi audio on videotape along with video signals.
audio-follow-video – (AFV) During video recording, the video signal is usually accompanied by an audio signal. Sometimes, during video editing, it is often necessary to separate the audio from the video signal. Audio-follow-video mixers allow accompanying audio to “follow” the video when switching video sources or not. Thed igital video mixer provides either function. 2. An operational mode in which audio and video switchers are tied together so that when the operator selects the video source, the audio simultaneously and automatically switches to the same source.
audio mixer – Device with user-adjustable controls to blend multiple sound inputs into desired composite output. See also mix.
audio processor – an electronic device used to manipulate audio signals in some manner.
audio signal – an electrical representation of sound.
audio sound – An electrical signal that carries sound information.
audio transduction – converting acoustical energy into electrical energy, or electrical energy back into acoustical energy.
auteur – A filmmaker, generally a director, who creates a body of work with a unified sensibility that reveals through the interplay of themes and styles, a personal worldview. The term originated with François Truffaut, whose 1954 essay “Une certaine tendence du cinéma français” put forth the idea that the most interesting films were those that functioned as a medium of personal expression–and therefore bore the distinctive imprint of their “author.” American critic Andrew Sarris later translated and expanded this idea into an “auteur theory,” which proposed an evaluation of films based on their context within the filmmaker’s oeuvre, rather than for their technical proficiency or greater historical significance. The term “auteur” later came to refer to any filmmaker who performed or was intimately involved in all aspects of the moviemaking process (writing, directing, producing, editing, etc.).
authored DVD – An authored DVD uses a specific file and folder structure to organize audio, video, navigation and backup information. You will see files with various extensions on an authored DVD. These include: .VOB, .IFO and .BUP.
auto assembly – 1. Process of assembling an edited video tape on a computerized editing system using an edit decision list. 2. Automatic combining of edits on videotape conforming to a prepared edit decision list (EDL) with little or no human involvement.
autoconforming – In general, autoconforming is the process where an offline-edited edit decision list (EDL) or cut list is used to reproduce the high-quality content of video and audio with the original source material.
auto-correct – See quantization.
auto cue – Also called autocue or teleprompter, used in broadcasting and also in videocasting. A news reader can type in the text he/she has to read when going live on TV. The software then scrolls the text over the screen at a predetermined pace adapted to the natural speed for that reader, so that it will sound like speaking instead of reading from a text. The screen is placed directly next to the camera targeted at the news reader, so that it looks like the reader is addressing you directly instead of just reading the text out loud. It demands a bit of practice to do this right. The best result is always after rehearsing the text a couple of times so that you know a large part by heart. That way you will not appear to be reading. There is a very cheap application that provides you with a teleprompter for your podcasts, namely Vlog It (bought by Adobe in the meantime). It works quite well when you put your camera just above the screen while reading the scrolling text.
autodetection – Autodetection is a function of the DVS CLIPSTER/Pronto video systems that allows the operator to automatically detect and set the video format and raster of the incoming video signal, for example, for a capturing.
automatic exposure – Circuitry that monitors light levels and adjusts camcorder iris accordingly, compensating for changing light conditions.
autoscaling – Scaling generally indicates a change of the resolution of images, i.e. the images are made larger or smaller. If the resolution of the original material differs from the configured raster, it will be scaled either up or down to its maximum allowable width and/or height according to the selected video format. The autoscaling setting makes sure that no image information gets lost, i.e. the images will not be cropped nor will they be too small for the selected video format.
available light – Amount of illumination normally present in a particular environment: natural light, artificial, or a combination.
avatar – A virtual representation of a user on a network, typically in text or graphic form. Avatars are often assumed identities with only an oblique relationship to their real-world counterparts.
axis – One of three vectors (X, Y, and Z) that define the three dimensions of a scene. Often defined as local space, object space, origin axis or world space.
axis of action – In the continuity editing system, the “Axis of Action” is an imaginary line that passes through the two main actors of a scene, defining the spatial relations of all the elements of the scene as being to the right or left. The camera is not supposed to cross the axis at a cut and thus reverse those spatial relations. Also called the “180° line.”