Lift gamma gain
Also known as: LGG, three-way color correction
The three primary grading controls, acting on shadows, midtones and highlights separately, which is how most colour correction is actually done.
Updated
What it means
Three controls divide the tonal range. Lift moves the shadows, gain moves the highlights, and gamma moves everything in between without touching either end. Nothing else in a grade is this easy to describe.
They overlap deliberately. Each one has a soft falloff, so an adjustment to the shadows leaves the midtones almost untouched and the highlights entirely alone. The softness is what makes them usable.
It is the faster relative of Curves. A curve is more precise; lift, gamma and gain are quicker to reach a result that looks right, and most corrections never need more than this.
How it works in practice
The order is lift, then gain, then gamma. Setting the Black point with lift and the white point with gain defines the range, and gamma places the midtones inside it. Reversing that means doing it twice.
Each control has a colour component as well as a brightness one. Pulling blue out of the shadows with lift is how a Color cast in the dark areas gets corrected without affecting skin.
Scopes make it repeatable. A Waveform shows where the ends have landed, which is what lets two clips be matched rather than approximated by eye, which is the difference between a grade and a guess.
What to watch out for
Gamma is the one that gets abused. Large midtone lifts flatten contrast and reveal noise, and the clip ends up looking washed rather than brighter. The midtones carry most of what a viewer notices.
Pushing gain too far clips highlights permanently. Highlight clipping at the top of the range is not recoverable afterwards, however the rest of the grade is arranged.
Per-clip adjustment by eye is how matching breaks. Twelve clips each corrected until they look fine produce twelve different looks, which is what Color matching then has to undo.
How RawClip handles it
Shadow, midtone and highlight levels are brought into agreement across the assembled sequence, which is what stops one clip reading as brighter than its neighbour. Footage recorded with consistent exposure needs less of that adjustment and survives it with more detail intact.