Color Grading and LUTs
Every film you love was shot flat. The camera captures a desaturated, low-contrast log image on purpose - to hold detail - and a colorist turns it into the look you remember. Grading is where color becomes storytelling: the cold dread of a thriller, the golden warmth of a memory, the inescapable teal-and-orange of the modern blockbuster. This is the interactive guide to the tools that get you there - lift, gamma, gain, log, and the LUTs that bottle a look.
What grading is
Color grading splits into two jobs. Primary grading affects the whole image: setting exposure and contrast, balancing the color so whites are neutral (or deliberately not), and shaping the overall mood. Secondary grading is surgical: isolating a single element - a face, a sky, a jacket - by its color, position, or a tracked mask, and adjusting only that. Primary sets the stage; secondary directs the eye.
Underneath both is one idea: a transfer function that maps every input pixel to an output pixel. A contrast tweak, a color balance, a stylized look - all of them are just functions from RGB to RGB. Once you see grading that way, the rest follows: tools like lift/gamma/gain are convenient shapes for that function, and a LUT is simply that function frozen into a table you can replay instantly.
Lift, gamma, and gain
The oldest and most intuitive primary controls are the three tonal ranges. Lift raises or lowers the shadows (it pivots around the black point), gain scales the highlights (it pivots around white), and gamma bends the midtones without moving the endpoints much. Together they reshape the tone curve into almost any contrast you want. Watch the curve and the image respond.
Reshape the tone curve
The three classic wheels, as a tone curve. Lift lifts the dark end, gain scales the bright end, and gamma bows the middle. The left panel plots the resulting input→output curve; the right shows it applied to a test image. Crush the lift and lower the gamma for a moody, contrasty grade; raise the lift for a faded, "film" look.
Color balance and the look
Apply lift/gamma/gain per channel and you are no longer just shaping tone - you are pushing color into specific tonal ranges. Cool the shadows toward teal, warm the highlights toward orange, and you have built the most recognizable grade in modern cinema. It works because skin tones sit in warm mid-highlights while a teal shadow is their near-complement, so faces pop against the background. Build the look.
Push shadows and highlights to opposite hues
Tint the shadows one way and the highlights another, weighted by each pixel's luminance. Drag shadows toward blue-teal and highlights toward orange for the classic cinematic split; or invert it for a colder, stranger mood. The midtones stay roughly where they are, which is what keeps skin looking natural.
LUTs: bottling a transform
Once you have a grade you like, you can freeze it into a LUT - a lookup table that
stores the output color for a grid of input colors. A 1D LUT remaps each channel
on its own (good for tone, useless for hue shifts). A 3D LUT stores a lattice of
RGB→RGB samples - say 33×33×33 points - and for any input in between, it
trilinearly interpolates the eight surrounding samples. That is how a single
.cube file can carry an entire camera-to-display look and apply it in real time. Watch
resolution matter.
Sample a grade into a cube, then interpolate it back
A fixed stylized grade is sampled into a 3D LUT of the size you choose, then applied to the test image by trilinear interpolation - exactly how real LUTs work. At tiny grid sizes the interpolation can't keep up and you see color errors and banding; raise the size and it becomes indistinguishable from the exact grade. The neutral ramp on top is the LUT's tone-and-tint response.
Why you grade in log
Cameras see a far wider range of brightness than a display can show. To keep both the bright window and the dark corner, they record in a log encoding that compresses that huge dynamic range into the available bits - the footage looks flat and milky, but nothing is thrown away. Grade that, and you have enormous latitude to push exposure and color before anything clips. Hand the colorist a display-ready Rec.709 image instead and the highlights are already gone. Push the exposure and compare.
The same scene, two encodings, pushed in exposure
A scene with a very wide brightness range, shown two ways: a display-ready Rec.709 bar and a log bar. Push the exposure up and down. The Rec.709 highlights clip hard to white and the shadows crush to black; the log version keeps gradation across the whole range - which is exactly why you grade the log, not the Rec.709.
The grading pipeline
A modern grade is a chain of transforms, and order matters. A typical node graph looks like this:
Best practices and pitfalls
Test your understanding
Six questions on grading, lift/gamma/gain, color balance, LUTs, and log. Instant feedback, no scores recorded - a wrong answer comes with a short explanation.
Quick check
Continue your journey
Grading sits on top of the camera's encoding, the display's gamut, and the transfer functions that connect them - here's where to go deeper.
Color in Film and Video
The wider craft of motion-picture color this grade lives in.
Digital · 14Gamma, Linear Light, and Transfer Functions
The encoding foundation that log curves build on.
Digital · 19HDR, Wide Gamut, PQ, HLG, and Modern Displays
The high-range targets a scene-referred grade delivers to.
Digital · 42Camera Color: From Photons to Pixels
Where log footage comes from before you ever grade it.
Colorimetry · 37Gamut Mapping
How the output transform fits your grade into a display.
Physics · 28Color Temperature and White Balance
The neutral starting point grading balances from.