What Is a LUT, Really? (And Why Free LUT Packs Usually Disappoint)
The plain version
LUT stands for Look-Up Table. It’s a list. For every colour that can come in, the table says what colour should come out.
A 33-point 3D LUT — the standard — defines 33 × 33 × 33 = 35,937 of those input/output pairs. Your editing software interpolates between them for everything in between. That’s it. No AI, no analysis of your image. Just a very large, very fast lookup.
Because it’s a fixed table, the same LUT produces the same transformation every time. Fast, predictable, and completely indifferent to what your footage actually looks like — which is both its strength and its limitation.
Two completely different jobs
Conversion LUTs are technical. They take a Log signal and correctly translate it to a standard display. There’s a right answer, defined by the camera manufacturer’s published maths. A conversion LUT is either accurate or it isn’t.
Creative LUTs are taste. Warm it up, crush the blacks, push shadows teal. No right answer, just style.
Most packs blur these together, which is why people end up with a look that also secretly mangles their colour science.
Why free packs usually disappoint
They’re built for the wrong format. A LUT made for S-Log3 applied to Apple Log will be wrong, because those formats place mid grey at completely different points — 41.1% versus 48.8%.
They ignore gamut. Converting the brightness curve without mapping the colour primaries gives you neon greens and strange skin.
They clip. Cheap LUTs slam highlights into pure white. A properly built one rolls off asymptotically.
How to test any LUT in 30 seconds
Point your camera at a scene with a bright window and a dark corner. Apply the LUT.
Does the window blow to featureless white? It clips.
Does skin go orange or waxy? Gamut problem.
Do the shadows go muddy or plasticky? Wrong transfer function.
A good conversion should look slightly boring — natural, neutral, ready to grade. If a conversion LUT looks dramatic on its own, it’s a creative LUT wearing a lab coat.
Where LUTs genuinely help
Speed and consistency. Twelve clips from three cameras on one timeline, each with the correct conversion, all matching. That’s an hour of work reduced to minutes.
Where they don’t
Exposure. Noise. Bad white balance. A LUT applies the same transformation to everything — it can’t know your shot was underexposed. Fix those first.
Our free conversion pack covers 11 Log formats, each built from the manufacturer’s published transfer function with proper gamut mapping. Test them against anything else you’ve downloaded — layrkit.com/free-pack
