Academy Color Encoding System

Definition

ACES (Academy Color Encoding System) is a standardized color encoding system developed by the Academy of Motion Picture Arts and Sciences (AMPAS). ACES provides a universal interchange format for digital film productions that preserves maximum color and dynamic range information throughout the entire production pipeline.

Core objectives of ACES:

• Universal Compatibility: Cameras, software and devices can interchange ACES material
• Long-term Stability: Material is future-proof and can be regraded later
• Maximum Color Depth: 32-bit Float with extreme dynamic range
• Creative Flexibility: Unlimited grading potential without quality loss

ACES is used by Hollywood studios, major streaming platforms and theatrical productions as an industry standard.

Technical Specifications

ACES Color Space and Gamut

ACES Primary Colors (not "physical" primaries, but mathematical ones):

Key Features:

• ACES Red and Blue are imaginary primaries (not realizable in visible color space)
• This enables gamut larger than 100% of human perception
• The largest color space in the industry: Can represent "virtual" colors

ACES Family (ACEScc, ACESproxy, ACESlog)

ACES consists of several sub-formats:

ACESap0 (ACES Primaries 0)

Raw, unprocessed format directly from sensor
32-bit Float, linear color space
Largest file volume
Usage: Archival, scientific applications

ACEScc (ACES Color Correction)

Optimized for grading
Log-like curve for more intuitive color correction
Faster to grade than linear ACESap0
Usage: Grading in DaVinci, Nuke

ACESproxy (ACES Proxy)

Compressed version for rapid preview
1/4 or 1/8 resolution possible
Fast to render, ideal for editing
Usage: Editorial, cutting, proxy workflows

ACESlog

Similar to camera log formats
Compromise between file size and grading flexibility
Less common than ACEScc

Workflow Integration

Camera to ACES Conversion

Red Digital Workflow:

• Red offers native ACES output (Red Rocket-X)
• REDengine 3 with ACES Input Transform
• REDlogFilm to ACES ACEScc directly in camera system

Arri Alexa Workflow:

• Arri Alexa LF and Mini LF support ACES export
• LogC.V3 to ACES convertible with Arri ColorTools
• Arri provides official ACES LUTs for all Alexa models

Sony F55/F65 and Others:

• S-Log to ACES via standard LUTs
• Sony ELC (Electronic Lens Correction) with ACES support
• Reverse engineering necessary for older cameras

DaVinci Resolve ACES Workflow

Project Setup:

Project Settings > Color Management
- Input Color Space: ACES (ACEScc or ACESproxy)
- Timeline Color Space: ACES (ACESap0 or ACEScc)
- Output Color Space: ACEScc for grading
- RRT (Reference Rendering Transform): For monitoring

Practical Implementation:

1. Digitization/Camera Output:

• Convert raw camera material (Red, Arri) to ACES
• Or create ACES proxies for rapid cutting

1. Editing Phase:

• Use ACESproxy for rapid preview
• Perform rough timing and sync

1. Color Grading Phase:

• Load ACEScc for grading (higher bit depth)
• Apply DaVinci automatic ACES Input Transform
• Grade with full ACES color space support

1. Output and Deliverables:

• Rec.709 SDR for broadcast
• Rec.2020 HDR for streaming
• DCI-P3 for cinema
• ACEScc as master archive

OpenFX Plugins and ACES

Many professional plugins support ACES:

Supported Software:

• DaVinci Resolve: Full ACES integration
• Nuke: ACES nodes (ACEScc, ACESproxy)
• Quantel Pablo/Rio: Broadcast HDR with ACES option
• Autodesk Flame: ACES for complex VFX
• Adobe After Effects: Third-party plugins

RRT - Reference Rendering Transform

Definition and Purpose

The RRT (Reference Rendering Transform) is a standardized curve used by ACES to convert the large ACES color space to smaller output spaces (Rec.709, DCI-P3, Rec.2020).

How it works:

ACES Material → RRT → Output Transform (Rec.709, DCI-P3, etc.)

Non-modifiable:

• The RRT is fixed in the ACES standard
• All implementations must be identical
• This guarantees compatibility between systems

Monitoring with RRT

On Set with RRT LUT:

• Convert ACES material with RRT to Rec.709
• View on standard monitors (SmallHD, Atomos)
• Accurate preview of final image

In Grading with RRT:

• DaVinci automatically displays RRT-transformed image
• Grading is performed in ACEScc
• RRT is applied for monitoring

Gamut and Dynamic Range in ACES

Extremely Large Gamut

ACES is larger than Rec.2020 and larger than DCI-P3:

Massive Dynamic Range

Logarithmic Encoding of ACES:

• Linear encoding: 0.0 (black) to 32767.0 (very bright)
• Practical range: Approximately 100+ stops dynamic range
• Sensor input can be directly mapped without information loss

Comparison:

Storage and Bandwidth Requirements

Data Size Comparison

ProRes (Rec.709):

4K (3840x2160) @ 24fps
ProRes 422 HQ: ~2.2 GB/min

ACES (ACEScc):

4K (3840x2160) @ 24fps
ACES 16-bit: ~1.8 GB/min
ACES 32-bit: ~3.6 GB/min

ACES (ACESproxy):

4K Proxy (1/2 resolution)
ACESproxy 8-bit: ~460 MB/min
ACESproxy 16-bit: ~920 MB/min

Storage Solutions:

1. Original Archive: Full-Res ACES ACEScc (or native Log)
2. Working Copies: ACESproxy for editing
3. Grading Master: ACEScc for final grade
4. Deliverables: Rec.709, DCI-P3, Rec.2020 (depending on medium)

Practical Implementation in Feature Films

Scenario 1: Hollywood Blockbuster with Red Workflow

1. Set: Red Komodo or Red Ranger

• Recording in Red native format
• On-Set LUT to Rec.709 for monitoring

1. Digitization:

• Convert Red Raw to ACES ACEScc (Red Rocket-X)
• Archive files

1. Editing:

• Create ACESproxy proxies
• Perform edit with proxies
• Conform to ACEScc masters

1. Grading:

• DaVinci with ACES ACEScc
• Full grading flexibility
• RRT for various output formats

1. Deliverables:

• DCI-P3 for theatrical release
• Rec.2020 HDR10 for streaming
• Rec.709 SDR for TV broadcast

Scenario 2: Independent Film with Mixed Camera Setup

• Camera 1: Arri Alexa Mini (LogC.V3)
• Camera 2: Sony FX30 (S-Log3)
• Audio/Light: Indie budget

Workflow:

1. Convert both log formats to ACES
2. Use ACES as master format
3. Grade with unified look
4. Export to various formats for distribution

Common Errors and Solutions

Adoption and Future Outlook

Current Adoption (2025)

Mainstream Studios:

• Universal, Warner Bros., Sony Pictures
• Streaming: Netflix, Apple TV+, Amazon Prime Video (for premium)
• Digital Cinema: 90% of cinema installations ACES-capable

Reasons Against ACES (still):

• Higher storage costs
• Longer grading times
• Specialized equipment required
• Small productions often cannot benefit

Future

ACES will increasingly become standard for:

• All streaming original content
• Premium documentaries
• Digital archival
• 8K and future formats

Summary

ACES is the industry standard for high-end film productions and digital archives. The enormous color space, massive dynamic range and maximum compatibility make ACES ideal for large productions, studios and long-term archival. The investment in an ACES workflow pays off through flexibility, quality and future-proofing.