Short answer
A LUT, or lookup table, is a stored colour transform: for each input value it gives an output value. In a film pipeline it does one of two jobs. A technical LUT converts between defined encodings, such as a camera's log to a display standard. A creative or show LUT carries a look agreed before the shoot. Its position matters more than its contents: it expects one specific input, and corrections belong before it, not after.
A technical table has a right answer. Converting LogC3 in ARRI's wide gamut to Rec. 709 with a given rendering is a defined operation, and the camera maker publishes it. RED notes that its output transforms are computed as mathematics and can also be represented as three-dimensional cube tables. A creative table has no right answer: it is a look. The same RED note describes a slot for a creative cube during grading, holding looks beyond what simple controls can express, placed before the output transform. Many tables in circulation fuse the two, which is convenient and is the source of most trouble with them.
A show LUT is the creative table a production commits to. It is built in tests before photography, loaded into the on-set monitors, used for dailies and kept as the starting point of the final grade, so that everyone from the camera crew to the editor sees one rendering. The Irishman used a table per period, emulating Kodachrome, Ektachrome and two strengths of ENR. Killers of the Flower Moon used three for phases of the story and a fourth to bring film and two kinds of digital camera to one stock's response. House of the Dragon used one, built to display a stop dark.
The account of Killers of the Flower Moon shows the arrangement precisely: the dailies colourist applied the tables and graded beneath them with printer-light adjustments only. A table is tuned for a correctly exposed, neutral input, so an exposure or balance error should be fixed in the scene-referred image first and then viewed through the table. Corrections applied after it act on values the table has already compressed, where a highlight pulled down reveals no more detail and a saturation increase lands on colours already at the edge of the gamut.
The Academy's Common LUT Format distinguishes a one-dimensional table, a curve applied to each channel separately, from a three-dimensional one, a lattice in which every combination of red, green and blue has its own output. Only the second can change hue and saturation selectively, desaturating greens while leaving skin alone. The lattice is sampled, commonly at 17 or 33 points per axis, and values between the points are interpolated, so a table can only approximate a transform with sharp features. The format's specification discourages grids above 128 per axis.
A table holds no record of what it expects or produces unless a person writes it in the file name. It cannot tell LogC3 from LogC4, narrow range from full, or an image that has already been transformed from one that has not. It is fixed: it cannot respond to the content of a shot. And a table built to output a display standard throws away everything above that display's white, which is why Dolby's grading guide tells colourists preparing an HDR master to remove or modify any table that limits dynamic range and colour.
| Production | What the record says |
|---|---|
| Blade Runner 2049 (2017) | Roger Deakins shot digitally in open-gate mode and viewed the image on set through the same lookup table he had used on Sicario, with few changes. The final grade was done with colourist Mitch Paulson. |
| Roma (2018) | The film was shot in colour on a large-format digital camera. Linear files were converted to a log encoding for grading, and a custom output transform, adapted from a show lookup table Emmanuel Lubezki had used on earlier films, supplied the overall look and the conversion to black-and-white. |
| The Irishman (2019) | Rodrigo Prieto gave each period its own lookup table: a Kodachrome emulation for the 1950s, Ektachrome for the 1960s, a light ENR emulation for the early 1970s and a heavier one after. They were developed with an image scientist and a colour scientist and finished with the colourists so that film and digital footage matched. |
| House of the Dragon (season one) (2022) | The series used one show lookup table that displays the image a stop darker than it was exposed, so the recording keeps room for adjustment. It was graded in HDR first, at 1,000 nits in a Rec. 2020 container, with the SDR version derived from that grade. |
| Killers of the Flower Moon (2023) | Three lookup tables carried the look: an emulation of Autochrome and Photochrom colour for the early part, an ENR emulation later, and a three-strip Technicolor emulation for the coda. A fourth matched all the capture formats to one film stock as processed at the production's laboratory. |
Why: It was built for a different input: another camera's log, or footage already converted for display.
Fix: Confirm the table's expected input and output from its documentation, and convert the footage to that input first.
Why: Corrections are being made after a table that outputs a display standard, where highlights have already been clipped.
Fix: Move the correction before the table, or replace the table with a scene-referred look followed by a separate output transform.
Why: A coarse lattice or poor interpolation is approximating a steep curve, often in an 8-bit pipeline.
Fix: Use a denser table, tetrahedral interpolation or the mathematical transform it was sampled from, at a higher bit depth.
Why: An SDR display table is still in the chain, limiting range before the HDR output.
Fix: Remove it and rebuild the look in the scene-referred image, as Dolby's guide advises.
Each statement is labelled by kind — established fact, a standard’s requirement, observed market data, a convention, or Colourwise’s own interpretation or analysis — with the strength of the evidence behind it.
StandardStrong evidence
The Common LUT Format, version 3.0, defines one-dimensional and three-dimensional lookup-table nodes with interpolation between sample points, and discourages three-dimensional grids larger than 128 points per axis.
FactStrong evidence
RED's IPP2 note states that its output transforms are performed as mathematics and can also be represented as three-dimensional cube tables, and that a creative cube for looks sits in the grading stage before the output transform.
Source: IPP2 Output Transforms (RED document 915-0201 Rev A)
FactStrong evidence
Dolby's grading guide instructs colourists creating an HDR master to remove or modify any lookup tables that may be limiting dynamic range and colour in the source images.
Source: Dolby Vision Color Grading Best Practices Guide, version 4.0
ConventionModerate evidence
Feature productions fix a look as one or more show lookup tables before or during photography and grade dailies beneath them with simple corrections; on Killers of the Flower Moon those corrections were printer-light adjustments only.
Source: Finessing Killers of the Flower Moon at Company 3 (Fred Schruers, American Cinematographer, 2 December 2023); Wages of Sin: The Irishman (Fred Schruers, American Cinematographer, 15 January 2020)
Reviewed 6 October 2026. Colourwise summarises its sources in its own words and does not reproduce standards text or proprietary colour data. Spotted an error? Tell us.