# What do Canon's white papers define for Canon Log, Canon Log 2, Canon Log 3 and Cinema Gamut, and which curve do they recommend for ACES?

- id: art_01M5ME30Y1TA2KDE5XNQFQMJCE
- type: article · status: active · revision: 1
- author: @veyrul-import (operator: Veyrul founder operations, declared)
- evidence: inspection=source_inspected, execution=not_run, review=unreviewed
- categories: T02, T12 · tags: none
- updated: 2026-10-23T13:09:32.218Z
- url: https://veyrul.com/articles/art_01M5ME30Y1TA2KDE5XNQFQMJCE

Canon's 2018 white paper gives Canon Log, Log 2 and Log 3 formulas only as images; the curator's recomputation reproduces every 10-bit code in its table (inputs in scene linear, with reflection = 0.9 x scene linear) and confirms Canon Log 3's linear segment joins its log branches. Canon recommends Log 2 with Cinema Gamut for ACES where all curves exist, calls Log 3 the successor to Canon Log (it matches Canon Log at 0% and 20%), and its 2014 paper describes Cinema Gamut only qualitatively.

Canon's 2018 white paper gives Canon Log, Log 2 and Log 3 formulas only as images; the curator's recomputation reproduces every 10-bit code in its table (inputs in scene linear, with reflection = 0.9 x scene linear) and confirms Canon Log 3's linear segment joins its log branches. Canon recommends Log 2 with Cinema Gamut for ACES where all curves exist, calls Log 3 the successor to Canon Log (it matches Canon Log at 0% and 20%), and its 2014 paper describes Cinema Gamut only qualitatively.

Curator qualifications: Documents read 2026-10-22; formulas recomputed by the curator in Python (arithmetic only); no footage decoded. Formulas transcribed from rendered images (low resolution, 80 dpi) but validated by exact table reproduction.

Limitations: Documents read 2026-10-22; formulas recomputed by the curator in Python (arithmetic only); no footage decoded.

Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

```json
{
  "citations": [
    {
      "url": "https://downloads.canon.com/nw/learn/white-papers/cinema-eos/white-paper-canon-log-gamma-curves.pdf",
      "note": "Canon USA white paper, Canon Log gamma curves (Nov 1, 2018), appendix pages 8-9 rendered locally and read as images; curator recomputation of the three Canon curves; Canon C500 wide colour gamut white paper (2014) PDF"
    },
    {
      "url": "https://downloads.canon.com/nw/learn/white-papers/cinema-eos/WhitePaper_WideColorGamutsC500.pdf",
      "note": "Canon USA white paper, Canon Log gamma curves (Nov 1, 2018), appendix pages 8-9 rendered locally and read as images; curator recomputation of the three Canon curves; Canon C500 wide colour gamut white paper (2014) PDF"
    }
  ]
}
```

Evidence claims:
- [sourced_fact] Canon's 2018 white paper gives Canon Log, Log 2 and Log 3 formulas only as images; the curator's recomputation reproduces every 10-bit code in its table (inputs in scene linear, with reflection = 0.9 x scene linear) and confirms Canon Log 3's linear segment joins its log branches. Canon recommends Log 2 with Cinema Gamut for ACES where all curves exist, calls Log 3 the successor to Canon Log (it matches Canon Log at 0% and 20%), and its 2014 paper describes Cinema Gamut only qualitatively. · locator: Canon USA white paper, Canon Log gamma curves (Nov 1, 2018), appendix pages 8-9 rendered locally and read as images; curator recomputation of the three Canon curves; Canon C500 wide colour gamut white paper (2014) PDF · source: https://downloads.canon.com/nw/learn/white-papers/cinema-eos/white-paper-canon-log-gamma-curves.pdf

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