What Is a LUT? Look-Up Tables in Photo & Video Explained
A LUT — short for look-up table — is one of the simplest and most powerful ideas in color work: a table that says, for every possible input color, exactly which output color to show instead. Feed it a flat, washed-out frame and a good LUT returns the same frame with cinematic contrast, shifted hues and a signature mood — instantly and identically every time.
Because a LUT is just a table of numbers, it works everywhere: photo editors, video editors like Premiere Pro and DaVinci Resolve, cameras, monitors, even game engines. That portability is why colorists trade looks as LUT files rather than as software-specific presets.
How a LUT actually works
Imagine a giant address book for colors. An input color — say a muted red — is looked up by its red, green and blue values, and the table answers with the color that should replace it, perhaps a deeper, warmer red. No math happens at application time; the transformation was baked into the table when the LUT was created. That's why LUTs apply in real time even on modest hardware.
Since storing every one of the ~16.7 million RGB colors would be wasteful, real LUTs store a coarse grid — commonly 17, 33 or 65 points per channel — and interpolate smoothly between the stored points. A 33-point 3D LUT holds 35,937 entries, which is plenty for a smooth, accurate look.
1D vs. 3D LUTs
A 1D LUT maps each channel independently: red in, red out. That's perfect for contrast curves and gamma corrections, but it can never say “shift blue-greens toward teal” because each channel is blind to the others.
A 3D LUT maps the full color coordinate — the combination of R, G and B — to a new color. That's what enables true color grading: hue shifts, split-toned shadows, film-stock emulation. When people talk about creative LUTs, they almost always mean 3D LUTs stored as .cube files.
When to use a LUT (and when not to)
LUTs shine when you need a consistent look across many images or clips, when you move a look between different applications, or when you want real-time preview on set. They are the lingua franca of color.
Their limitation: a LUT is spatially blind. It transforms colors, not regions — it cannot brighten just a face or darken just a sky. That's what masks and local adjustments are for, which is why a full editing recipe is more expressive than a LUT alone.
Creating your own LUT
The classic workflow: grade a reference image, then export the transformation as a .cube file. In RawCut you can do this in one click — build a look in the Sandbox (or borrow any community recipe), press “.cube”, and the exact WebGL-rendered transformation is baked into a standard 33-point LUT that loads in Premiere, Resolve or Final Cut.
Frequently asked questions
Is a LUT the same as a filter or preset?
No. A filter or preset stores editing instructions (slider values), which stay editable. A LUT stores the finished color transformation as a table. LUTs are more portable; presets are more flexible.
Do LUTs reduce image quality?
A well-made LUT with 33+ grid points introduces no visible quality loss. Very small LUTs (8 or 16 points) can show banding in smooth gradients.
Can I use a video LUT on photos?
Yes — a .cube LUT is just a color mapping and works identically for stills and footage, as long as it was designed for the same kind of source (e.g. standard-contrast images rather than log footage).
Load any .cube file — or one of our film-stock looks — onto your own photo in the RawCut Sandbox. No install, nothing leaves your device.
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