Glossary

Terms as used in this handbook.

A

AAF: Advanced Authoring Format. An open interchange specification published by the AMWA (Advanced Media Workflow Association, formerly the AAF Association), primarily used by Avid for picture and audio turnovers. Binary, supports multi-layer timelines and keyframed speed ramps. Not to be confused with MXF, which is a SMPTE standard (ST 377-1) and whose structural metadata derives from AAF's data model. See Edit List Generation.

ACES: Academy Color Encoding System. A standardized colour-management framework: one scene-referred interchange encoding (ACES2065-1), working spaces derived from it, defined transforms at each end of the pipeline, and a container. See ACES.

AMF: ACES Metadata File. An XML sidecar that records which ACES transforms a shot or show uses: Input Transform, look transforms, Output Transform, so a pipeline's colour configuration travels with the material instead of living in someone's notes.

AOV: Arbitrary Output Variable. A supplementary render pass (normal maps, z-depth, and so on) stored as an additional channel in an OpenEXR file. See OpenEXR.

ASC CDL: American Society of Cinematographers Color Decision List. A deliberately restrictive color correction interchange format limited to slope, offset, power, and saturation. The ten values transfer reliably only when sender and receiver agree on the working space: the CDL defines no colour space of its own, so the same numbers applied to differently encoded images give different results. Agreeing the space is the whole job. The numbers are the easy part. See Plate Pre-Grading.

ASC MHL: Media Hash List. An ASC-published format for recording checksums of copied media so that a transfer can be verified rather than assumed. The practical defence against silent corruption during offloads and archival.

B

BRAW: Blackmagic RAW. Blackmagic's camera format, which replaced CinemaDNG in 2018 and is recorded across the URSA Cine family. Partially demosaiced in-camera, which is why it behaves more like a light RAW than a full sensor dump.

C

Camera RAW: Unprocessed sensor data preserved for creative interpretation later. Inherently scene-referred. Inefficient as a VFX working format because it must be debayered on every access. See Camera RAW.

CBB: Could Be Better. A visual effects shot deemed passable as-is but slated for improvement if schedule permits. See Digital Intermediate.

Colorist: The artist responsible for the final look of the picture, working with the filmmakers to craft it and maintaining continuity across the show. See Responsibilities of the Colorist.

Comp: Composite. A finished visual effects shot, assembled from a plate plus rendered or painted elements. Also the verb for making one.

Concatenation: The collapsing of multiple successive image transforms into a single net operation, avoiding the cumulative softening of repeated resampling. Broken by interposing color or shader nodes. See Concatenated Image Transforms.

Conform: Reconstructing the show's timeline at full quality from camera original and VFX elements, using metadata from the offline edit. See Editorial Turnover for DI.

D

Dailies: Footage processed and delivered for review shortly after it is shot, usually with a viewing LUT applied, for the director, cinematographer and editorial. See Digital Dailies.

DCDM: Digital Cinema Distribution Master. An unencrypted render in DCI-X'Y'Z', almost always carried as 16-bit TIFF, though note the distinction between container and content: ST 428-1 defines the code values as 12-bit, which the 16-bit TIFF simply pads. The exception is the packed-image form of ST 428-24, which stores those 12-bit values in losslessly compressed JPEG 2000 instead. A DCDM is the source a DCP is made from, but not only that. It is also delivered as a mastering element in its own right, and archived. See Theatrical Distribution Masters.

DCP: Digital Cinema Package. The compressed, usually encrypted package delivered to theaters. See DCP.

Data window / display window: In OpenEXR, the region containing image data versus the visible frame area. These may differ, and in practice DI systems handle the difference inconsistently, Resolve, for instance, simply truncates pixels outside the display window. Worth testing on your own setup rather than assuming the overscan survives. See OpenEXR.

Debayer: Demosaic. Reconstructing full-colour pixels from a sensor's Bayer-patterned photosites, where each site records only one of red, green or blue. Debayering happens when Camera RAW is decoded, which is why RAW files carry no fixed resolution or colour until they are processed.

Digital intermediate (DI): The stage where a show is conformed, VFX are integrated, colour grading happens, and every deliverable is mastered. Named for the photochemical intermediate elements it originally replaced. See Where the name comes from.

Display-referred: Image encoding defined in relation to display characteristics, with no numeric relationship to real-world exposure. The state of any image intended for exhibition. ISO 22028-1 calls this same state output-referred. The two terms are interchangeable and you will meet both. See Display-Referred Imagery.

DIT: Digital Imaging Technician. Responsible for on-set ingest, backup, and often on-set look creation. See Digital Dailies.

DNx: Avid's codec family, rebranded in 2025 from the DNxHD/DNxHR names to five quality levels (444, HQX, HQ, SQ, LB). Resolution-independent, and all levels now support 8- to 16-bit encoding and an optional alpha channel. See Avid DNx.

Dolby Vision trim: An authored pass in which a colourist sets, per shot or per scene, how the HDR grade should be reduced to lower-capability displays. The trim is carried as dynamic metadata rather than baked into a separate master. See HDR Mastering.

DSM: Digital Source Master. The graded master a show's deliverables are derived from. DCI deliberately does not specify its format, colour space or encoding. It is defined by what the production and its distributors agree on, and in practice one show may carry several (Rec.709, Rec.2020/HDR10, P3-DCI and Dolby Vision versions are all commonly requested separately). Sometimes skipped in favour of producing a DCDM directly. See DSM.

E

EDL: Edit Decision List. The oldest and simplest interchange format. Universally supported, human readable, but unable to describe variable speed ramps or geometric effects. See EDL.

EOTF / OETF / OOTF: Electro-Optical, Opto-Electronic, and Opto-Optical Transfer Function. The OETF maps scene light to code values (a camera's job). The EOTF maps code values to displayed light (a display's job). The OOTF is the net scene-to-display rendering, including the intended artistic rendering. Conflating the OETF and EOTF of a standard is a common and consequential error.

EXR: OpenEXR. The standard image format for scene-linear and VFX work, storing half-float (IEEE 754 binary16) or full-float pixels, arbitrary channels, and a data window that may differ from the display window. See OpenEXR.

F

FFOA: First Frame of Action. The reference point marking where the program picture begins, used to align head leaders and the 2-pop. Also written FFOP (First Frame of Picture). FFOA is the form used in most delivery specifications. See Leaders and Tail-Pop.

Frame padding: Deliberately recording image area outside the intended frame lines to preserve latitude for stabilization and reframing. See Frame Padding.

Framing chart: A photographed chart or generated pixel-accurate reticle communicating intended framing unambiguously. See Framing Charts.

H

Handles: Extra frames beyond the edit at the head and tail of a plate or comp, giving editorial room to roll a cut. See Frame Numbering and Handles.

HLG: Hybrid Log-Gamma. A relative HDR transfer function designed for broadcast, where the display maps the signal to its own peak. Contrast with PQ, which is absolute. Both are defined in ITU-R BT.2100.

I

IDT / ODT / RRT: Input Device Transform, Output Device Transform, Reference Rendering Transform: the original ACES 1.0 names. Current ACES documentation says Input Transform and Output Transform. Since ACES 1.1, the RRT and ODT are concatenated into a single Output Transform rather than applied in sequence. The old names persist in software menus.

IMF application: A constrained profile of the Interoperable Master Format specifying which essence encodings a package may use. App #2E (ST 2067-21) is the common JPEG 2000 profile. App #4 is for archival cinema masters, App #5 carries ACES, and RDD 45 carries ProRes. See IMF.

L

LFOA: Last Frame of Action. The reference point marking where the program picture ends, used to align tail leaders and the tail pop. Also written LFOP (Last Frame of Picture). LFOA is the form used in most delivery specifications. See Leaders and Tail-Pop.

LMT: Look Modification Transform. In ACES, a look applied in the scene-referred domain, before the Output Transform, as distinct from a display-referred grade. The right place for a show LUT-style creative look inside an ACES pipeline.

Longplay: The film assembled as a single continuous sequence rather than divided into reels. See Working in Reels.

LUT: Look Up Table. A pre-computed color transformation, either technical (standards-based) or creative (subjective, s-shaped, scene-to-display). A 1D LUT maps each channel independently and so cannot remap a gamut or mix channels. A 3D LUT samples the RGB cube and can. The Academy/ASC Common LUT Format (CLF) is the interchange format that carries either, along with ASC CDL operations, in a single documented XML container. See Look Up Tables.

M

Matte: A channel isolating an element of a composite, delivered to the DI so the colorist can grade composite regions selectively without re-rotoscoping. See Working with Visual Effects Mattes.

MaxCLL / MaxFALL: Maximum Content Light Level and Maximum Frame-Average Light Level. Static HDR metadata describing the content, specifically the brightest pixel and brightest frame average. This contrasts with ST 2086, which describes the mastering display. See HDR Mastering.

MXF: Material Exchange Format. A SMPTE-standardized container (ST 377-1) that wraps essence with structural metadata. Used for IMF and DCP track files and for Avid's OP-Atom media. Its metadata model derives from AAF's.

N

Nit: Informal name for the candela per square metre (cd/m²), the unit of luminance. SDR mastering references 100 nits. HDR grading displays are commonly 1,000 or 4,000.

O

OCIO: OpenColorIO. An open-source colour-management library, now an Academy Software Foundation project, that lets applications share one colour configuration. The practical mechanism by which a facility applies a consistent pipeline across different software. See Color Management and OpenColorIO.

Opticals: Effects reproducible during conform: resizes, repositions, stabilization, flips, flops, simple timewarps, dissolves, locked-off split screens. Named for the optical printing required in the negative-assembly era. See Opticals List.

OTIO: OpenTimelineIO. An open-source, vendor-neutral timeline interchange format and API, originated at Pixar and now an Academy Software Foundation project. Used mostly as programmatic glue for translating and validating edit lists rather than as a native turnover format. See OTIO.

OTT: Over-the-top. Streaming distribution outside traditional broadcast and cable.

Output Transform: In ACES, the transform that converts graded ACES data to a specific display encoding. Replaced the separate RRT + ODT pair as a user-facing concept in ACES 1.0, and became a genuinely concatenated transform in ACES 1.1.

P

Plate: Camera original footage delivered to visual effects as the basis for a shot. See Visual Effects Plate Pulls.

PQ: Perceptual Quantization, standardized as SMPTE ST 2084. An absolute HDR transfer function: a code value maps to a specific luminance in cd/m², so the creative intent is pinned to measurable light. Contrast with HLG. See HDR Mastering.

Previz: Previsualization. CGI animatics used to plan complex shots and sequences before production. See Pre-Production.

ProRes: Apple's professional codec family, published as SMPTE RDD 36, with MXF carriage in RDD 44 and an IMF application in RDD 45. The 4444 variants sustain multiple generations without meaningful degradation. See Apple ProRes.

ProRes RAW: Apple's camera-acquisition RAW format (2018). Despite the shared name it is not a member of the ProRes intermediate family and is not applicable to transcoded VFX plate pulls.

Proxy: A lower-resolution or lower-bandwidth copy of media, used so that editorial and review can work without the storage and throughput the full-resolution material demands. Distinct from a deliverable: a proxy is never what ships.

R

Reel: A ~20-minute division of a feature, inherited from the physical limits of print stock and retained because it parallelizes editorial and grading labor. See Working in Reels.

RGC: Reference Gamut Compression. An ACES transform that maps out-of-gamut values, which a wide encoding like AP0 readily produces from real cameras: back into a workable range, so that downstream operations behave predictably instead of producing artefacts around saturated highlights.

Roundtrip: Sending material out of a system and bringing it back, then verifying that nothing changed but the intended work. The standard proof that a pipeline is correctly configured. See zero net change.

S

Scene-linear: Linear encoding of relative light values in floating point, with middle gray at 0.18 and each stop doubling. Values may exceed 1.0. See Scene-Linear.

Scene-referred: Image encoding defined in relation to the scene's relative exposure values, retaining the camera's native dynamic range. See Scene-Referred Imagery.

Show LUT: The single scene-to-display transformation chosen for a project. Drives on-set monitoring and sits at the end of the grading pipeline. The digital equivalent of print stock. See The Show LUT.

Slap comp: A rough temporary composite made in editorial to convey a story beat before the real shot exists. See Creative Editorial.

Slate frame: An informational frame prepended to a delivered comp carrying shot, version, vendor, artist, and framing details. See Frame Numbering and Handles.

ST 2086: SMPTE's static HDR metadata standard describing the mastering display, including its primaries, white point, and minimum and maximum luminance. Frequently confused with MaxCLL/MaxFALL, which describe the content instead. See HDR Mastering.

T

Tape name: The unique source identifier that, with timecode, links a timeline clip back to camera original media. Without it, conform is guesswork. See Edit List Generation.

TD: Technical Director. At a VFX studio, the person responsible for defining and vetting the imaging pipeline. See Visual Effects Quality Control.

Turnover: The delivery of edit lists, media, and references from editorial to the DI or to VFX. See Editorial Turnover for DI.

Two-pop: A single-frame audio and picture sync reference two seconds before first frame of picture. See Leaders and Tail-Pop.

U

USD: Universal Scene Description. Pixar's open-source framework for describing, composing and interchanging 3D scenes, now an Academy Software Foundation project and the emerging standard for moving scene data between applications.

W

WIP: Work in progress. An unfinished VFX shot delivered so grading can begin in parallel. See Digital Intermediate.

Z

Zero net change: The principle that non-VFX regions of a plate must come back through the compositing pipeline unaltered, with no unintended colour space or encoding shift. Where the plate and the comp share a format and encoding this is literally bit-identical and should be verified by differencing. Where the pipeline crosses formats, such as a DPX plate returning as EXR, the requirement is that the difference be zero within the precision of the encoding, not that the bits match. See Visual Effects Production.