Advanced Authoring Format (AAF) - Professional file interchange format designed for the video post production and authoring environment. AAF files help address the problem of multi-vendor, cross-platform accessibility for computer based digital video production

Aces- Short for Academy Color Encoding System. ACES is a postproduction specification that helps ensure that the color the cinematographer intends is the color the audience sees. The system uses 16-bit linear storage. The benefits of Sony S-Gamut, S-Log 2 and 16-bit linear RAW recording become very clear as the transform into ACES color space works beautifully.

Additional Dialogue Replacement (ADR) - Post production process where the actor substitutes the recorded audio on set with dialogue recorded in studio. This is mainly used to improve audio quality as well as dubbing to another language.

Alpha Channel - Another name for key channel – a channel to carry a key signal.

Archive - Long-term storage of information. Video, audio and metadata stored in digital form can be archived and recovered without loss or distortion.

ASC CDL- Short for American Society of Cinematographers Color Decision List. A tool that enables color decisions early in the workflow to be accurately communicated to subsequent stages. For example, decisions made during On-Set Look Management can be sent to Dailies and Color Grading.

Aspect Ratio - The ratio of length to height of pictures. All TV screens used to be 4:3 (4 units across to 3 units in height), but now almost all new models, especially where there is digital television, are widescreen, 16:9. Pictures presented this way are believed to absorb more of our attention and have obvious advantages in certain productions, such as sport. In the change towards 16:9 some in-between ratios have been used for transmission, such as 14:9.

Avid Log Exchange (ALE) - File format primarily intended for exchanging video logging data between programs.

Bayer Filter / Mask Array - A Bayer array is a pattern of red, green and blue non co-sited filters placed onto an imaging chip (CCD, CMOS) so that it can capture the separate red, blue and green primary colors of the image to make up a color digital image. As our eyes have more resolution for green light than red or blue, there are twice as many green cells as there are red and blue. Some redundancy of the green pixels produces an image which is less noisy and has finer detail than would be achieved if there were and equal number of red, green and blue cells. The R, G and B pixels generated by the Bayer filter need to be ‘unmasked’ using a complex algorithm to produce white. Traditionally professional TV cameras have used three image sensors, one to pick up each primary color. This arrangement demands that the three are finely registered together and involves a considerably more bulky construction and cost than the still digital cameras and consumer camcorders that use a single chip sensor with a Bayer, or other similar filter. However most new high-end professional cameras now have just one sensor.    

Checksum - A simple check value of a block of data intended to recognized when data bits are wrongly presented. It is calculated by adding all the bytes in a block. It is fairly easily fooled by typical errors in data transmission systems so that, for most applications, a more sophisticated system is preferred.

Chromatics - The science of color is sometimes called chromatics, chromatography, colorimetry, or simply color science. It includes the perception of color by the human eye and brain, the origin of color in materials, color theory in art, and the physics of electromagnetic radiation in the visible range (what we commonly refer to simply as light).

Chrominance - The color part of a television signal, relating to the hue and saturation but not to the brightness or luminance of the signal. Thus pure black, gray and white have no chrominance, but any colored signal has both chrominance and luminance. See Also - Luminance

Codec - Originally short for a combination of a coder and decoder but now often used to describe just one or the other. Mostly codec refers to a compression coder or decoder such as JPEG, MPEG, ProRes  or DNxHD.

Color Correction - Color Correction is the process of adjusting the color of a clip to get the best out of the material or to match shots perhaps taken at different times or in different lighting conditions. In film, grading was traditionally done when going from internegative to print film by controlling the exposure of the film. In television it was traditionally done off the telecine for commercials or tape-to-tape for longform programs. Either way, both processes were by their nature linear. The advent of non-linear grading systems has once again changed the rules for color correction. While there is still a requirement for an initial technical scan for film-originated material, from this point on, grading can – and often does – happen at multiple stages in the post production process. It is now possible – and usually desirable – to color correct individual layers within composites (which may be shot under different lighting conditions) to ensure that the result is harmonious within itself, and non-linear working means that scene-to-scene comparisons and corrections can be made as the edit unfolds. This eases the final grading process when the finished work is reviewed interactively with the director/client. Secondary color correction is aimed at controlling a particular color or a narrow range of colors – such as those on a car or product. Here typically the hue, gain and saturation can be changed. There are also several methods available for defining the object, area or ‘window’ of required color correction such as using wipe-pattern shapes, drawing an electronic mask by hand or a combination of automatic and by-hand methods. See Also - Grading

Color Cube (3D LUT) - A representation of color space by a three-dimensional diagram. For example, all definable colors of an RGB color space can be contained in an RGB color cube where R, G and Bare axes at right angles to each other (like x, y and z at the corner of a cube). Different color spaces and interpretations of color are defined by different color cubes. If the exact spectral values of R, G and B are defined, that cube defines an absolute color space. Such cubes are available from a number of vendors. See Also - LUT, Color Management

Color Decision List - The American Society of Cinematographers’ Color Decision List (ASC-CDL) is a proposed metadata interchange format for color correction, developed to ensure that images appear the same when displayed in different places and on different platforms. This should enable consistency of look from on-set monitoring through post production to the final grade.

Color Management - The management of color through a process, such as DI or video grading. Television engineering folklore says that a picture never looks exactly the same on two picture monitors. Certainly it has been hard to achieve a convincing match... until now. By the use of probes to measure the colors on a screen, and equipment with adjustable color LUTs, the look of color can be set to the same across all monitors – within their technical limits. See Also - Color Cube (3D LUT), LUT

Color Space - The color range between specified references. Typically three references are quoted in television: for example RGB, Y R-Y B-Y and Hue, Saturation and Luminance (HSL) are all color spaces. In print, Cyan, Magenta, Yellow and Black (CMYK) are used. Film is RGB while digital cinema uses X ́Y ́Z ́. Moving pictures can be moved between these color spaces but it requires careful attention to the accuracy of processing involved. Operating across the media – print, film and TV, as well as between computers and TV equipment – will require conversions in color space.

Compression (Audio) - Reduction of bandwidth or data rate for audio. Many digital schemes are in use, all of which make use of the way the ear hears (e.g. that a loud sound will tend to mask a quieter one) to reduce the information sent. Generally this is of benefit in areas where bandwidthor storage is limited, such as in delivery systems to the home, handheld players, etc.

Compression (Video) - The process of reducing the bandwidth or data rate of a video stream. Digital compression systems analyze their picture sources to find and remove redundancy both within and across picture frames. The techniques were primarily developed for digital data transmission but have been adopted as a means of reducing broadcast transmission bandwidths and storage requirements on disks.

Dailies - Unedited footage shot during the making of a motion picture. Usually at the end of each day, that day's footage is developed, synced to sound, and exported for viewing the next day by the director and some members of the film crew. However, the term can be used to refer to any raw footage, regardless of when it is processed. See Also - Editorial Dailies, Viewing Dailies

DCI- Short for Digital Cinema Initiatives, an industry standard-setting body. The DCI standard encompasses image containers of 2K (2048 x 1080) and 4K (4096 x 2160).

Deliverables - Material that is delivered for use by customers – TV channels, agencies, Web, DVD, mobile phones, etc. The business of making deliverables has expanded with the widening of the scope of digital media.

Digital Cinematography - Shooting movies with digital cameras – not film. This growing practice generally makes use of cameras designed specifically for the purpose. These differ from the television application in that the full range of brightness captured by the image sensors is offered at the output as raw data, allowing color grading, format changes, etc. to be executed as a part of the digital intermediate process. Television cameras are designed to work live, and so they include front-end processing for gamma correction, set-up for the required color look and clipping to suit home viewing conditions.

Digital Image Technician (DIT) - Production crew member working closely with the cinematographer to assist in managing media and image manipulation.

Digital Negative - Digital image material that contains all the detail (spatial and dynamic/latitude) held in the original camera negative (OCN) film. This allows all latitude headroom to be included on the material for use in a DI process so adjustments of color and exposure can be made to the same degree as with film.

DNxHD - Video codec created by Avid and intended to be usable as both an intermediate format suitable for use while editing and as a presentation format.

DPX -Digital Picture Exchange is a common file format for digital intermediate and visual effects work. The file format is most commonly used to represent the density of each color channel of a scanned negative film in an uncompressed "logarithmic" image where the gamma of the original camera negative is preserved as taken by a film scanner.

Dual Link - The bandwidth of SDI and HD-SDI links allow the transport of uncompressed 4:2:2 sampled video and embedded digital audio. Dual links are often used to carry larger requirements– such as video with key (4:2:2:4), RGB (4:4:4) and RGB with key (4:4:4:4). See also: 4:2:2, 4:4:4

Dynamic Range - For images – the measurement of the range of brightness in a scene expressed as a ratio or the Log10 of the ratio. Typically a lighting cameraman will try to keep a scene to less than 40:1 to avoid loss of detail in the print. A 100:1 contrast range in a scene is the typical maximum.

Edit Decision List (EDL) - Used exclusively in the post production industry, these lists contain an ordered list of reel and timecode data representing where each video clip can be obtained in order to conform and complete the final cut.

Editorial Dailies - When dailies are processed, the files that are needed to edit with are sent to the post production house, these files can be imported to any editing software, giving the editor the ability to edit with one clip containing audio and video together. See Also - Dailies, Viewing Dailies

Electronic Press Kit (EPK) - A "Behind the Scenes" segment used to showcase the production crew and actors at work.

Essence - The material that television programs are made of. In other words, the video, audio and any other material such as graphics and captions that are added to make up the final result. See Also - Metadata

Exposure - Exposure refers to the amount of light that falls on a film or light sensor. In a camera this is controlled by both time with the shutter, and the effective lens aperture, referred to as the F-number or T-number.

Film Formats - Unlike pre-HD television, which had only two image formats, 525/60I and 625/50I, 35 mm film has many. Of these the most common are Full Frame, which occupies the largest possible area of the film, Academy and Cinemascope. The scanning for these is defined in the DPX file specification as follows: At full frame, 4K - 4,096 x 3,112 2K - 2,048 x 1,556 1K - 1,024 x 778 Aspect Ratio - 1,316   These scan sizes generally represent the valid image size within the total frame size indicated by full frame. It is generally considered that all scanning is done at full frame size as this avoids the complexity of adjusting the scanner optics or raster size with risks associated with repeatability and stability. Although these digital image sizes came about as formats for scanning film, new digital cinematography cameras are also using them, exactly or nearly. In the file-based world of DI the exact size does not matter, as long as it’s managed correctly and, most importantly, able to produce high quality output for release prints and digital cinema – where the DCI specifies exact sizes.

Final Color - The last step in the color-grading process, usually containing secondary coloring touch-ups. See Also - Color Correction

Finishing - Finishing services are generally performed at or near the end of editing a movie, episode, or commercial.  These services can include conforming, final color, VFX work, final audio mixing, creating deliverables, and archiving of the completed project and elements.