Why your LUT looks wrong on log footage
The most common LUT complaint: it looked right in the preview, but on your footage the result is milky and flat — or violently oversaturated with orange skin. Nine times out of ten this is not a broken LUT. It's a colour-space mismatch.
Two kinds of image data
Display-referred data is ready for a screen: sRGB photos, JPEGs, web images, exported frames. Black is 0, white is 1, and the values in between look right to eyes. Log footage from cameras is different on purpose: to squeeze a wide dynamic range into the file, the camera records a flat, low-contrast, desaturated signal that is meant to be transformed before viewing.
What happens on a mismatch
A LUT is a fixed mapping: for input colour X, output colour Y. A LUT built from display-referred images expects display-referred input. Feed it log and every input lands in the wrong region of the cube: log's lifted blacks read as "brightened shadows", its muted chroma reads as "desaturate further". The output is grey mush. The reverse mistake — a log-expecting conversion LUT applied to normal video — produces the crushed, oversaturated version.
The fix: normalise first
Convert the log footage to a display-referred state before the creative LUT:
- Use your editor's colour-space transform (input: your camera's log flavour, output: Rec.709/sRGB), or the camera maker's official conversion LUT, as the first step;
- then exposure and white-balance corrections;
- then the creative LUT, last.
After normalisation, footage behaves like the images the LUT was built from, and the look lands as designed.
How to tell which kind of LUT you have
If the LUT came from photos, screenshots, or a browser tool working on sRGB images, it is display-referred. If it's named after a camera process (log-to-Rec.709 style names), it's a technical conversion LUT. Keep the two roles in separate nodes and the pipeline stays debuggable.
Tonemara does all of this in your browser in one click: drop a reference
image and your own photo, preview the match free, and export a 33×33×33 .cube
LUT plus a Lightroom-compatible .xmp preset. Your images never leave your device.