# How do practitioner and digital-era sources qualify film-era lighting-ratio rules?

- id: art_01M5MT4476VZJHTWG00QZ428YK
- 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: 2026-10-23T16:39:51.262Z
- url: https://veyrul.com/articles/art_01M5MT4476VZJHTWG00QZ428YK

The inspected sources do not replace the 1953 numbers with a digital equivalent. They move the decision to measured stops from exposure tests (CML, film era), consistency within a scene's coverage, light meter/false colour/waveform checks, and the trade between raising key and cutting fill for noise versus highlight headroom (Deakins forum, 2023 and 2025). No manufacturer sensor-latitude statement was retrieved, so any digital numeric rule is unsupported here.

The inspected sources do not replace the 1953 numbers with a digital equivalent. They move the decision to measured stops from exposure tests (CML, film era), consistency within a scene's coverage, light meter/false colour/waveform checks, and the trade between raising key and cutting fill for noise versus highlight headroom (Deakins forum, 2023 and 2025). No manufacturer sensor-latitude statement was retrieved, so any digital numeric rule is unsupported here.

Curator qualifications: All quotes verified. The flagged 'conflict' is a reported range of practitioner preferences (ratios rejected, used, or useful for teaching), not contradictory evidence. The 4:1 ceiling is tied to colour film in the 1953 source; no digital-sensor ceiling is supported (producer bound correct). Attribution of the 'T-stops and ratios' reply is ambiguous in the mailing-list signature layout (Nick Anthony vs Brent Reynolds); cite it as 'a list participant'. Reclassify conflicting_evidence as a range of practitioner views.

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

```json
{
  "citations": [
    {
      "url": "https://cinematography.net/edited-pages/LightingRatios.htm",
      "note": "producer work copy work/cn.raw; producer work copy work/dk1.raw; producer work copy work/dk2.raw; producer work copy work/sg.raw; producer work copy work/mm.txt"
    },
    {
      "url": "https://www.rogerdeakins.com/forums/topic/lighting-ratios/",
      "note": "producer work copy work/cn.raw; producer work copy work/dk1.raw; producer work copy work/dk2.raw; producer work copy work/sg.raw; producer work copy work/mm.txt"
    },
    {
      "url": "https://www.rogerdeakins.com/forums/topic/contrast-ratio-2/",
      "note": "producer work copy work/cn.raw; producer work copy work/dk1.raw; producer work copy work/dk2.raw; producer work copy work/sg.raw; producer work copy work/mm.txt"
    },
    {
      "url": "https://education.siggraph.org/static/HyperGraph/lighting/lighting_film_video.htm",
      "note": "producer work copy work/cn.raw; producer work copy work/dk1.raw; producer work copy work/dk2.raw; producer work copy work/sg.raw; producer work copy work/mm.txt"
    }
  ]
}
```

Evidence claims:
- [sourced_fact] The inspected sources do not replace the 1953 numbers with a digital equivalent. They move the decision to measured stops from exposure tests (CML, film era), consistency within a scene's coverage, light meter/false colour/waveform checks, and the trade between raising key and cutting fill for noise versus highlight headroom (Deakins forum, 2023 and 2025). No manufacturer sensor-latitude statement was retrieved, so any digital numeric rule is unsupported here. · locator: producer work copy work/cn.raw; producer work copy work/dk1.raw; producer work copy work/dk2.raw; producer work copy work/sg.raw; producer work copy work/mm.txt · source: https://cinematography.net/edited-pages/LightingRatios.htm

Rights:
- documentation: license=unknown hosting=permitted redistribution=permitted modification=unknown training=unknown · Applies to this original summary only, not to the cited sources.

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