A/B Printing: Printing from original film stock which has been conformed into two rolls with alternating shots and black opaque leader. This methodology will eliminate any potential splice marks from showing up on prints and permits the incorporation of optical effects and titles. (Film Editing)

A/B Rolls: Two or more rolls of film having alternate scenes intercut with opaque leaders in such a way that the 'A' roll presents its picture at the same time that the 'B' roll presents opaque leader, and vice versa. (Film Editing)

Above the Line: Refers to the creative elements of a production such as the writer, producer, director and actors. Literally, these are the elements which appeared above a bold line which divided standard production budget sheets. (Production)

AC: Alternating Current. An electric current with periodically changing polarity (i.e. 60 times a second for 60Hz power). (Electricity)

Accent Light: A light unit that emphasizes one subject. This might be a key light, a kicker, or a backlight. (Lighting)

Acetate Base: The tranparent cellulose acetate plastic film which for years served as the backing for magnetic recording tape. (Sound Recording)

Acetone: An organic liquid chemical used in the manufacture of some types of film cement. Also used to clean film splicing equipment. (Film Editing)

Acoustics: The science of the transmission of sound waves. Generally refers to the characteristics of auditoriums, theatres and studios with respect to their design.

Action Cutting: The cutting of film from one shot to another in a way yielding the impression that action is continuous and uninterrupted. (Film Editing)

ADC: Analog-to-Digital Converter. An electronic device used at the input of digital audio equipment to convert analog electrical signals to digital values whose numbers represent the level and frequency information contained in the original analog signal. (Sound)

ADR: Automatic Dialog Replacement. Also known as "looping." A process of re-recording dialog in the studio in synchronization with the picture.

Address Track: A control/timing track on the edge of videotape which contains control data for quick and accurate location of program material.

Aerial Shot: An extremely high angle view of a subject usually taken from a crane or a high stationary camera position, but may also refer to a shot taken from an actual airplane or helicopter. (Production).

Aliasing: An undesirable distortion component that can arise in any digitally encoded information (sound or picture).

Ambient Light: General, nondirectional, room light. (Lighting)

Ambient noise: The total sound in a given are which is peculiar to that space (room tone). (Post Production)

Amplitude: The strength of an electronic signal as measure by its waveform height. (Sound)

Amplitude Distortion: The nonlinear relation of input and output induced harmonics which is a function of voltage
fluctuations or power consumption. (Acoustics)

Analog: An electrical signal that continuously varies in strength as related to some form of input.

Analog Recording: A means of recording audio or video whereby the recorded signal is a physical representation of
the waveform of the original signal.

Anamorphic: An optical system having different magnifications in the horizontal and vertical dimensions of the image.

Angle of View: This is the size of the field covered by a lens, measured in degrees. However, because of the aperture masks in film, the angle of view for a given lens is generally described in terms of the height and width of a lens. (Cinematography).

Answer Print: The first print combining picture and sound which is submitted by the laboratory for the customer's approval. (Laboratory)

Anti-Aliasing: Filtering of erroneous frequencies that are created during the analog to digital conversion process. (Sound/Picture)

Aperture: A variable opening inside a lens that regulates the amount of light reaching the image plane. Also known as an iris. (Camera/Lighting)

Apple Box: A box build of a strong wood or plywood which is capable of supporting weight. These may be of various sizes, the smallest of which is also known as a 'pancake' because it is nearly flat. (Lighting/Grip)

Arc: A lighting unit that generates illumination from an electrical arc between two carbon electrodes. (Lighting)

Aspect Ratio: The proportion of picture width to height (1.33:1, 1.66:1, 1.85:1 or 2.35:1).

Asperity Noise: (Hiss) Noise that is caused by minute imperfections in the surface of a recording medium (tape). (Sound)

ASA: The exposure index or speed rating of a film which denotes the film's sensitivity.

Assemble: The work of organizing and joining the shots of a film in the sequence in which they will appear in the finished print. (Film Editing)

Associate Producer: This is normally the person who acts as the liason between a production company and the various personnel involved in the post production process.

Associational Editing: The juxtaposition of shots in order to present contrast, comparisons or ideas. (Film Editing)

Asynchronous Sound: Sound which is indigenous to the action but not precisely synchronized with the action.

Atmosphere: Extras who are staged and photographed to portray normal human traffic needed to add detail in various script situations. (Production)

Attenuate: To reduce a signal's strength.

Audible Spectrum: When wave motion in the atmosphere has a frequency that lies between 20 and 15,000 Hz it produces a sound which is apparent to the average human. (Acoustics)

Automatic Slating: A camera attachment which records the film shot and take numbers and a visible sync mark which corresponds to a tone fed to an audio recorder.

A-Wind: An indication of the emulsion position on a roll of film. An 'A' wind is a roll with the emulsion facing the center of the roll. (Film Editing)