Colour · ACES
The ACES pipeline, named.
ACES is a colour pipe with a fixed order. The camera log goes in. A scene-linear interchange is the middle. You grade in ACEScct. One Output Transform aims the result at a screen. Skip a step, or do it twice, and the lehenga is no longer the colour you shot.
- Camera
- →IDT
- →ACEScct
- →LMT
- →Output
- →Display
Where you grade
The working space is ACEScct. AP1 primaries, log, with a toe so the shadows do not fall away the way they do in ACEScc. This is the timeline. ACEScg is the linear AP1 space for rendering, not for a wedding grade. ACES2065-1 is for exchange, not for the wheels.
ACES 1 against ACES 2
The order did not change. The rendering did. ACES 2 is the pipe to build now. A show look from 1.x does not survive the move unchanged.
The tone
1.x The RRT shapes the mids hard. Faces pick up contrast before you ask for it.
2 The tone scale is calmer. Highlights roll off more slowly, so a flame and a thread keep detail longer.
The red
1.x Tonemap ran on AP1 RGB channels. A saturated lehenga can twist as it hits the shoulder.
2 Tone and gamut mapping run in a colour-appearance space, then back out. Saturated red stays nearer itself.
The name
1.x People still say RRT and ODT. In practice they were already one Output Transform.
2 One Output Transform, aimed at a display: primaries, white point, and the luminance you are actually screening.
Old looks
1.x An LMT built under 1.x includes the way that RRT behaved.
2 The same LMT on a 2.0 output is a different picture. Rebuild the look. Do not paste it.
On this desk
- Colour science: ACES 2.0. Timeline: ACEScct.
- An IDT on every clip, matched to the log that camera recorded.
- The wedding grade as nodes in ACEScct. Skin and red stay separate. That is the LMT.
- One Output Transform, Rec.709 gamma 2.4. No second CST and no Rec.709 LUT after it.