LUT stands for “look-up table.” A LUT is a tool that lets filmmakers, editors, and colorists save particular color grades as a template. Think of a LUT as a color preset that a filmmaker can readily turn to when working on a project. For instance, the color editing process may require a team to convert a color space from a standard color space for televisions (such as Rec. 709) to a cinema standard color space (such as DCI-P3). If a colorist has one or more cinematic LUTs on file, they will find it easy to make this conversion.

Filmmakers, colorists, and editors use LUTs because they are convenient. Rather than create an entire color space from scratch every time you work on a video editing project, you can facilitate the color grading process by applying a LUT that comes with preset color profiles

Colorists use many types of LUTs for different purposes. Here are some of the most common:

1. Transformation LUT: This type of LUT transforms an image from one color space to another.
2. Viewing LUT: Camera crews use viewing LUTs on monitors during filming so that flat color spaces like S-Log or Log C (which capture low-contrast images with muted colors) can appear as something more usable (such as Rec. 709).
3. Calibration LUT: Colorists apply calibration LUTs to reference monitors or projectors to ensure uniform color characteristics (from skin tones to landscapes) in all stages of the editing and coloring process.
4. Log normalization LUT: This type of LUT tone-maps log footage into a standard color space like Rec. 709 or a cinematic color space like DCI-P3.
5. 1D LUT: A 1D LUT sets a display's white point, color balance, and overall contrast. The key is that a 1D LUT can only control one single value setting, which makes it less versatile than a 3D LUT. When searching for 1D LUTs online, look for files ending in a “.lut” extension.
6. 3D LUT: A 3D LUT captures a more complex color gradient than a 1D LUT can provide. As the name implies, 3D LUTs establish color and luma (the luminance of colors) in a three-dimensional color space by managing hue, saturation, and brightness. When searching for 3D LUTs online, look files ending in a “.cube” extension.

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