VFX Glossary

3D: 1) Referring to spaces or objects: Having width, height, and depth. Set up a 3D scene in Maya.
2) Referring to a kind of movie: A stereoscopic viewing medium that gives the illusion of images with depth. I use stereo to refer to these kinds of films in order to reduce confusion. Gravity was one of the only movies I thought was really worth seeing in 3D.

ACES: The Academy Color Encoding System, a proposed industry standard for color management. ACES is not itself a color space, but an entire ecosystem of color spaces and workflow guides.

ACEScg: A color space defined by ACES for use in computer graphics applications, including rendering and compositing. If you’re doing VFX work in an ACES pipeline, your images should almost certainly be in ACEScg.

Adobe After Effects: A layer-based compositing software published by Adobe. After Effects is popular for motion graphics, having superior text-handling capabilities and integration with Adobe’s Premiere non-linear editor.

After Effects: A layer-based compositing software published by Adobe. After Effects is popular for motion graphics, having superior text-handling capabilities and integration with Adobe’s Premiere non-linear editor.

Blackmagic Fusion: Node-based image compositing software published by Blackmagic Design. Fusion is a budget-friendly compositor with a version integrated into Blackmagic’s Resolve non-linear editor and color correction software. Previously published by Eyeon.

Blackmagic Resolve: A budget-friendly all-in-one post-production software that includes color-correction, non-linear editing, audio production, and compositing.

CG (Computer Graphics): In industry jargon, we often refer to any image based on 3D models, and the department that produces them, as “CG” to distinguish it from the 2D compositing department.

CGI (Computer Generated Images): A term used by journalists and audiences to disparage our work. It implies that the computer is doing the creative work, and the badness of a film is usually measured by its over-reliance on “CGI.” A more appropriate term is VFX or Visual Effects.

Cineon: 1) A logarithmic color space used by film digitization scanners.
2) A file format with the extention .cin used for scanned digital film negatives.

Clip: A specific, short piece of video or film. Sometimes a segment of a scene, sometimes only a single shot, but always contained in a single video file or image sequence.

Code Value: The numbers used to describe the luminance of a pixel. For instance, in an 8-bit integer system, a pixel might have a Red code value of 127, which translates to 50% of the available brightness values. Code value by itself is meaningless without knowing the transfer function used to convert it to luminance.

Color Management: The discipline, tools and techniques that ensure that color definitions and renditions remain the same through every step of the production process.

Color Space: A way of organizing and describing color. A color space is comprised of three things: Gamut, the range of colors the color space can describe; Transfer Function, the mathematical relationship between code values and luminance; and White Point, the coordinates in the chromaticity diagram that are considered to be white.

Comp: Short for Composite.

Composite: 1) An image made from more than one source. These sources can be multiple photographic elements or videos or synthetic imagery. My composite is too dark, but when I brighten it the grain looks really bad.
2) The working document that produces the composite image. In Fusion, the file has a .comp extension. You need to organize your comp better; I can’t tell which mask does what.
3) The act of creating a composite image. When will you be finished compositing that shot?

Compositing: 1) In the most general terms, the process of combining images together. Ideally, multiple elements are combined in such a way as to make it appear as though they were all photographed by the same camera at the same time.
2) The department in a Visual Effects unit responsible for performing compositing work. Sometimes also the 2D department, although compositors often also work in 3D.

Compositor: 1) A skilled artist and technician who creates composite images. I am a digitial compositor for MuseVFX.
2) Software used to create a composite, such as Blackmagic Fusion. Sometimes it’s quicker to relight in the compositor than to send a shot back to 3D.

Composition: 1) A working document used to create a composite.
2) The artistic arrangement of forms within the frame of view.

Chromaticity Diagram: An esoteric, horseshoe-shaped chart that plots all human-perceptible color on an x/y plane. Sometimes called the CIE 1931 xy chromaticity diagram.

Cut: 1) To set the in and out points of a clip.
2) To assemble a film or video project from individual clips. He’s been cutting his film for the last three weeks.
3) To insert a clip into a film or video project. Cut the latest version of that clip in, then we’ll review.
4) The current form of a film or video project. The editor has sent us a new cut, so we’ll need to verify our shot lengths again.
See also, Edit.

Display LUT: A Look-up Table that converts an image in the working color space to your monitor’s color space. Also called the Display Transform. The Display LUT might not be an actual LUT—the term is used often in a generic sense for any transform to the display color space.

Display Transform: The color transform that converts an image in the working color space to your monitor’s color space. Also called the Display LUT, although the transform may not actually be a Look-up Table.

Dome Light: A spherical distant light source that illuminates a 3D model from all sides. An environment light is usually mapped with a High Dynamic Range panoramic image (HDR or IBL) that represents the environment the model is in. Environment lights quickly give a realistic base lighting that can be augmented with more traditional virtual lights. Also called an Environment Light.

DPX: Digital Picture Exchange, a file format used to hold digital “film” negatives. Typically contains an image using a logarithmic color space, but the specific color space is not defined by the format. DPX files are uncompressed and typically contain 10-bit or, less commonly, 12-bit images. Other bit depths are allowed but very seldom used.

Edit: 1) To assemble a film or video project from individual clips. We’re done with photography; time to edit!
2) A change to a project or clip. Did you make that edit I asked for?
3) The current form of a film or video project. Everybody come to the screening room; we’re going to watch the latest edit.

Editor: The artist and technician responsible for assembling a film or video project.

Environment Light: A spherical distant light source that illuminates a 3D model from all sides. An environment light is usually mapped with a High Dynamic Range panoramic image (HDR or IBL) that represents the environment the model is in. Environment lights quickly give a realistic base lighting that can be augmented with more traditional virtual lights. Also called a Dome Light.

EXR: Probably someone knows what EXR stands for, but they’re not telling. My best guess is “EXtended Range.” A file format invented by Industrial Light and Magic (ILM) to enable efficient storage of linear, high dynamic range images. The industry standard working file format for visual effects.

Final Cut: 1) The version of a film or video project that is considered finished. Not to be confused with Fine Cut.
2) A common editing software suite owned by Apple.

Fine Cut: A version of a film or video project that is close to finished but not yet approved. Timings are probably close to correct, and some visual effects and sound work may already be done. Large changes may still be made, but they are less common. Intermediate between the Rough and Final cuts.

Flow (Fusion): The node graph where tools are displayed. Also, Flowgraph, Flow View,or Node Graph.

Footage: Literally, the length of a segment of film. Colloquially, any piece of video or film of any length. The videographer is shooting some footage today.

Foundry Nuke: Node-based image compositing software published by Foundry. The current industry standard for film and television production.

Fusion: Node-based image compositing software published by Blackmagic Design. Fusion is a budget-friendly compositor with a version integrated into Blackmagic’s Resolve non-linear editor and color correction software. Previously published by Eyeon.

Gamma: A non-linear function sometimes used to compress luminance values such that more room is available for the darkest parts of an image, where our eyes are most sensitive. Very few color spaces use a pure gamma transfer function, but the term is often used as shorthand. Inverse of Power (exponent).

Gamut: 1) The range of colors that a color space is capable of encoding.
2) The range of colors that a specific device is capable of displaying or recording.

HDR (High Dynamic Range): 1) Slight short-hand for “HDRi,” or High Dynamic Range Image (see HDRi)
2) A broad term for a television or computer monitor display capable of emitting light with a broader dynamic range than traditional displays do. An HDR computer monitor requires a compatible graphic card and software capable of producing HDR images. Most modern video game consoles are capable of sending an HDR signal, and smart TVs will usually adapt automatically to programs with HDR content.

HDRi (High Dynamic Range Image): A type of image file that captures a greater dynamic range than is possible in images intended for direct viewing. An HDRi is usually stored with a linear color space in an OpenEXR or .hdr (radiance) file format. These images are often panoramic, meaning they capture a 360-degree dome or sphere in a single image, and are used to light CG models (Image Based Lighting, or IBL) and generate reflections. Sometimes just “HDR.”

Head Mounted Display (HMD): A display device that you wear on your head. Typically a Virtual or Augmented Reality visor.

High Dynamic Range Image (HDRi): A type of image file that captures a greater dynamic range than is possible in images intended for direct viewing. An HDRi is usually stored with a linear color space in an OpenEXR or .hdr (radiance) file format. These images are often panoramic, meaning they capture a 360-degree dome or sphere in a single image, and are used to light CG models and generate reflections.

HMD:A display device that you wear on your head. Typically a Virtual or Augmented Reality visor.

IBL (Image Based Lighting): A CG lighting technique in which the physical set’s lights are captured in a panoramic High Dynamic Range Image which is then mapped onto a large sphere in the 3D software and used to light a model. It is an easy way to quickly get realistic base lighting that matches primary photography, although additional virtual lights are usually needed to augment the IBL. Often synonymous with the terms HDR and Environment Light.

Image Based Lighting (IBL): A CG lighting technique in which the physical set’s lights are captured in a panoramic High Dynamic Range Image which is then mapped onto a large sphere in the 3D software and used to light a model. It is an easy way to quickly get realistic base lighting that matches primary photography, although additional virtual lights are usually needed to augment the IBL. Often synonymous with the terms HDR and Environment Light.

Image Sequence: A series of numbered still images that create a video clip when viewed rapidly in sequence. Most visual effects software works most efficiently with image sequences rather than encoded video files. Render that Quicktime out to an image sequence to get better performance in Fusion.

Layer-based compositing: A compositing paradigm that uses image elements in a stack. Photoshop and After Effects are layer-based compositors. Layer-based systems sometimes use destructive techniques that are irreversible once the Undo buffer has been cleared.

LDR (Low Dynamic Range): An uncommon term that means “not HDR.” The more common and appropriate term is Standard Dynamic Range (SDR).

Linear: A transfer function in which the relationship between code values and luminance is a straight line. That is, doubling the value of a pixel also doubles the amount of light that pixel emits. Note, however, that your eyes are not linear, so doubling the luminance doesn’t necessarily make something “twice as bright.”

Locked Cut: A version of a film or video project where the timings are approved and not subject to change. Many VFX vendors insist on a locked cut before they begin work in order to reduce costly change orders. Also, Picture Lock.

Logarithmic: A term in mathematics and statistics related to exponents. A logarithmic scale can represent a very large range of output values with a much smaller range of input values at the cost of less precision for the large values. Commonly used as a method of compressing image data because the majority of important detail in an image is in the dimmest parts, but most of the dynamic range in the world comes from bright lights or the sky.

Log footage: 1) Footage with a color space using a logarithmic transfer function. Such an image looks desaturated and low-contrast, often described as “milky.” DPX and Cineon files are often stored with a log color space.
2) The process of creating an inventory of the clips recorded for a project, importing them into the editor, and organizing them prior to beginning the editing process.

Look-Up Table (LUT): A table of input code values to output code values that converts one color space to another. LUTs come in a variety of formats with different capabilities. They can usually interpolate values between entries in the table, but they cannot extrapolate beyond the boundaries of the table, which can lead to color clipping in images with extreme values.

Low Dynamic Range (LDR): An uncommon term that means “not HDR.” The more common and appropriate term is Standard Dynamic Range (SDR).

Luminance: A measure of the amount of light a pixel produces. With reference to a physical device, luminance is measured in nits or candela per square meter. Without reference to a device, luminance is abstract. Conventionally, a value of 1.0 in a floating-point representation is arbitrarily taken to be paper white.

LUT (Look-Up Table): A table of input code values to output code values that converts one color space to another. LUTs come in a variety of formats with different capabilities. They can usually interpolate values between entries in the table, but they cannot extrapolate beyond the boundaries of the table, which can lead to color clipping in images with extreme values.

Merge: The most basic of compositing operations. A Merge combines two input images to produce an output image. The most common Merge operation is the Over (or Atop), which places a foreground (A in Nuke) over a background (B).

NLE (Non-Linear Editor): A film editing system that allows the editor to make changes anywhere on the time-line they like, in any order. This kind of editor is typically a computer-based digital system, although the first non-linear editors used magnetic tape.

Node: A self-contained tool that performs a specific, usually simple, task. Nodes are connected to one another on the Flow/Network Editor in order to collectively create more complex effects.

Node-based compositing: A compositing paradigm that uses discrete nodes to perform sequential operations on an image. Fusion and Nuke are node-based compositors. Compare to Layer-based compositing. Node-based compositing is, by its nature, non-destructive and preferred for professional visual effects production.

Non-Linear Editor (NLE): A film editing system that allows the editor to make changes anywhere on the time-line they like, in any order. This kind of editor is typically a computer-based digital system, although the first non-linear editors used magnetic tape.

OpenEXR: Probably someone knows what EXR stands for, but they’re not telling. My best guess is “EXtended Range.” A file format invented by Industrial Light and Magic (ILM) to enable efficient storage of linear, high dynamic range images. The industry standard working file format for visual effects.

Optical Effects: The old way of doing visual effects used a device called an optical printer to layer images together.

Picture Lock: The state of a film or video project in which no further changes to timing are expected. See also, Locked Cut.

Rec.709: A color space designed for digital broadcast television. Rec.709 has a transfer function very similar to (but not identical with) a 2.2 gamma curve. sRGB and Rec.709 share the same color primaries and white points. The two spaces are therefore identical when linearized.

Resolve: A budget-friendly all-in-one post-production software that includes color-correction, non-linear editing, audio production, and compositing.

Rough Cut: A preliminary version of a film or video project. Timing is subject to change, visual effects and sound are probably temporary.

SDR (Standard Dynamic Range): A term invented to distinguish displays and signals that are not High Dynamic Range from those that are. The typical computer monitor is SDR, as is any television manufactured before 2014 or so. More recent televisions may still be SDR-only, but they will probably say so in their specifications.

Sequence: 1) A set of related shots containing a continuous or progressing effect. In this sense, the sequence is often the largest organizational category in a visual effects project. The werewolf transformation sequence from An American Werewolf in London
2) A set of typically consecutive scenes in a story that contribute to a single narrative chunk. The recruiting sequence in The Magnificent Seven.
3) A set of numbered image files that make up a clip. See Image Sequence.

Shot: Typically the smallest discrete element of a video or film project, from cut to cut. Most visual effects tasks are performed on a shot basis.

SFX: 1) Sound Effects. Audio added in post-production to enhance the action of a film. Without additional context, this is probably the meaning intended by most industry professionals.
2) Special Effects. Due to the possibility of confusion, the abbreviation is seldom used for special practical effects and even less often for visual and optical effects.

Special Effects (SFX): A general term for imagery in a project that are somehow illusory or use visual tricks to show something that did not actually happen. This can include Visual Effects, which usually means digital effects work, and on-set practical effects like explosions created by gasoline or air cannons. When used inside the industry, it usually refers to practical effects, with digital or optical work being called VFX.

Special Visual Effects: An Emmy Awards category for visual effects. We don’t know why they think it’s so special. Probably an ampersand was omitted thirty years ago and nobody noticed.

sRGB: A color space designed for computer monitor displays. sRGB has a transfer function very similar to (but not identical with) a 2.2 gamma curve. sRGB and Rec.709 share the same color primaries and white points. The two spaces are therefore identical when linearized.

Standard Dynamic Range (SDR): A term invented to distinguish displays and signals that are not High Dynamic Range from those that are. The typical computer monitor is SDR, as is any television manufactured before 2014 or so. More recent televisions may still be SDR-only, but they will probably say so in their specifications.

Transfer Function: The mathematical relationship between the code values in an image and the luminance they represent. The most naïve version of a transfer function is the gamma, or power, curve, which uses a simple exponent to map numbers to luminance. Gamma is often used as an inaccurate shorthand for the transfer function.

Trim1) To set the in and out points of a piece of footage.
2) The in or out point of a piece of footage. Usually specified as “Trim In” or “Trim Out.” That clip has too many frames at the head. Trim in four frames so it lines up to the cut.

VFX (Visual Effects): Effects added to a film or video project during post-production using either digital or optical printing technology (the latter being effectively a dead art these days). Currently, the majority of VFX work is done on a contract basis by independent vendors hired by the production.

Visual Effects (VFX): Effects added to a film or video project during post-production using either digital or optical printing technology (the latter being effectively a dead art these days). Currently, the majority of VFX work is done on a contract basis by independent vendors hired by the production.