What Is a LUT in Color Grading?

A LUT (Look-Up Table) is a mathematical preset that transforms color values in an image. It maps input colors to output colors, allowing quick application of color corrections, creative looks, or technical conversions.

How LUTs Work

A LUT is essentially a table that says "for input color X, output color Y." Instead of calculating complex color transformations in real-time, the software looks up the result in the table — hence "look-up table."

For example, a LUT might transform:

• Flat, low-contrast LOG footage → Normal-looking Rec. 709
• Standard video → Film-like color palette
• Rec. 709 → P3 cinema color space

Types of LUTs

1D LUT

Transforms each color channel (R, G, B) independently. Used for:

• Gamma/lift/gain adjustments
• Contrast curves
• Simple tonal corrections

1D LUTs are small and fast but limited — they can't handle complex color relationships.

3D LUT

Transforms colors based on the combined R, G, B values. Can handle:

• Complex color grading looks
• Color space conversions
• Hue-specific adjustments

3D LUTs are larger (typically 33×33×33 or 65×65×65 cube) but much more powerful.

Common LUT Types in Production

Technical LUTs

• Camera LOG → Rec. 709: Converts flat camera footage to viewable range.
• Color space conversions: Rec. 709 → P3, sRGB → ACEScg.
• Display calibration: Matches monitor to standard.

Creative LUTs

• Film emulation: Mimics the look of specific film stocks.
• Style looks: Cinematic looks, vintage effects.
• Show LUTs: Custom looks developed for specific productions.

LUTs in the Production Pipeline

1. On-set: DIT applies a viewing LUT so LOG footage looks normal on monitors.
2. Editing: Editor applies the same LUT to maintain consistent look during dailies.
3. Color grading: Colorist works on the underlying LOG footage, building a new grade that may incorporate or replace the on-set LUT.
4. Delivery: Final LUTs may be exported for archival or format conversion.

LUT File Formats

LUT Limitations

• Non-reversible: A LUT "bakes in" a look — you can't easily undo it without the original.
• Footage-specific: A LUT designed for ARRI LOG-C won't work correctly on Sony S-Log.
• No intelligence: A LUT applies the same transform regardless of content — it won't adjust for different skin tones or lighting.