Fundamentals
Colour Management
Why your footage looks grey and flat out of camera. Why colours shift on export. Why the same grade can look different on different screens. Three concepts that explain almost everything.
01 Colour gamut
A gamut defines the range of colours a camera, file, or display can contain. The horseshoe represents all colours visible to the human eye. Each colour space is a triangle within it. Bigger triangle = more colours. When you deliver in a smaller gamut than you shot in, those extra colours have to be squeezed inward.
R G ↑ B ↓ D65 x chromaticity y chromaticity
Key insight: wider gamut means more colours available. But you must tell every tool in your pipeline which gamut you are using, or the numbers are meaningless.
02 Transfer function
The transfer function (also called a gamma curve) defines how a number in your file maps to actual brightness on a screen. LOG footage looks flat because it uses a curve designed for grading rather than for viewing directly.
input (scene light) output value 0 1
Simulated frame
LOG · S-LOG3
Key insight: LOG footage is not wrong. It just needs a conversion step before it looks right. Skip that step, or use the wrong one, and every tone and colour in your grade will be built on a mistake.
03 The colour pipeline
Every frame travels through a chain of colour space transforms from the sensor to the screen. Getting this chain right is the difference between colours that hold up and colours that fall apart. Tap each stage to see what is happening.
Camera
sensor
›
Log /
RAW
›
Working
space
›
Output
transform
›
Display
Camera sensor
↓
Log / RAW encoding
↓
Working colour space
↓
Output transform
↓
Display
Key insight: specify the colour space at every stage and the system works. Leave any stage undefined and colours are guesswork. Usually wrong guesswork.
04 Bit depth
Bit depth controls how many distinct brightness values your camera can record per colour channel. More values means smoother gradients and more room to push in the grade. The problem appears when you grade LOG footage aggressively. You are stretching a compressed range of values across a wider output range, and if there were not enough values to begin with, you see the steps.
Gradient after LOG shadow expansion
Banding becomes visible when compressed tones are stretched in the grade
Key insight: 8-bit is fine for footage shot in a standard picture profile that you will not be pushing hard in the grade. For LOG or RAW footage you plan to grade heavily, aim for 10-bit minimum. 12-bit if your camera offers it.