# LUT (Look-Up Table)

Source: https://storiara.com/glossary/lut
Last updated: 2026-09-14
Author: Nick Harty, Storiara

> A LUT, or look-up table, is a small file that converts each input color value to an output value. On productions it is mostly used to transform flat log footage from the camera into a normal-looking or stylized image for monitors, dailies, and editorial proxies, without changing the original camera files.

## How a LUT works in plain numbers

Log camera footage is recorded flat so the file keeps as much highlight and shadow detail as possible. On a normal monitor it looks gray and washed out. A LUT is a table: for each input value, it lists an output value. A 3D LUT stored as a 33-point .cube file samples 33 steps for each of red, green, and blue, which is 33 x 33 x 33 = 35,937 color entries. Values that fall between those points are interpolated.

Take one pixel of skin tone recorded in log at red 0.48, green 0.40, blue 0.36 (on a 0 to 1 scale). A show LUT might output red 0.62, green 0.47, blue 0.39: more contrast, a little warmer. Every pixel in the frame goes through the same table, which is why a LUT is fast enough to run live on a camera monitor.

## The LUT's path through a production

In prep, the [director of photography](https://storiara.com/roles/director-of-photography) shoots tests and builds a show LUT with a colorist. The file then travels:

| Stage | Who applies it | What it affects |
|---|---|---|
| On set | DIT or camera assistant loads it into monitors and camera | Director and video village see the look |
| Dailies | [DIT](https://storiara.com/roles/digital-imaging-technician) or dailies lab, plus per-scene CDL adjustments | Dailies screeners and [proxy files](https://storiara.com/glossary/proxy-files) |
| Editorial | Baked into proxies | What the editor and producers watch for months |
| Final grade | Colorist loads the log originals, may start from the LUT | The finished image |

At the final [color grading](https://storiara.com/glossary/color-grading) session, the colorist works from the untouched camera originals. The LUT is a reference, and the colorist may replace it with a proper color-managed pipeline for the deliverable color spaces.

## Mistakes that cost time

Using the wrong LUT for the camera's log curve is the most common problem. A LUT built for one manufacturer's log encoding will produce odd contrast and color on another, which shows up fast on a mixed A and B camera package. Label LUT files with camera, log format, and version (for example `LONGDRIVE_ARRI_LogC4_v3.cube`).

Recording the LUT into the camera originals causes worse damage. Once baked in, clipped highlights cannot be recovered in the grade. Record log and apply the LUT only to monitoring outputs and proxies.

Version changes are the last trap, especially when nobody tells the lab. If Day 12 dailies used v3 and Day 13 used v4, the editor cuts between shots that look like they came from two different movies, and people waste hours before anyone checks the metadata.

## Where it connects

LUT versions belong in the camera department's notes and on the [camera report](https://storiara.com/glossary/camera-report), and the final LUT or color pipeline is documented in the post workflow document. The finished grade, not the LUT, is what goes into the [deliverables](https://storiara.com/glossary/deliverables) and gets checked in the [QC report](https://storiara.com/glossary/qc-report).

## Frequently asked questions

### What is the difference between a 1D and 3D LUT?

A 1D LUT adjusts each color channel independently, which handles contrast and gamma curves. A 3D LUT maps red, green, and blue together, so it can change hue and saturation. Show LUTs for camera footage are almost always 3D, usually saved as .cube files.

### Is a LUT the same as a grade?

No. A LUT is a fixed transform applied the same way to every frame. A grade is shot-by-shot work by a colorist that balances, matches, and shapes each image, often starting from the show LUT.

### Can a LUT damage the footage?

Not when used as a viewing LUT, since it only changes what is displayed. The risk is baking a LUT into camera recording or into files that are later treated as originals, which throws away highlight and shadow detail.

### Where does the show LUT come from?

Usually the director of photography builds it in prep with a colorist or DIT from camera tests, then the same file goes to the monitors on set, the dailies lab, and editorial.