showstack / glossary / cri
CRI (Colour Rendering Index) 顯色指數
A single number summarising how faithfully a source renders a set of test colours against a reference illuminant. The general figure, Ra, averages eight pale test samples. R9 — the deep red sample — is not in that average, which is why a source can post a high CRI and still render skin and reds badly.
中文
以單一數值概括光源相對於參考光源、還原一組測試顏色的忠實度。一般公布的 Ra 值是八個淺色測試樣本的平均。深紅色樣本 R9 並不在這個平均之內，因此一支光源可以標示很高的顯色指數，卻仍然把膚色與紅色還原得很差。
Regional usage
| Where | Term | Note |
|---|---|---|
| UK / US | CRI / Ra | |
| HK / TW | 顯色指數 / 演色性 |
Easy to get wrong
CRI 95 says nothing on its own about R9. Ask for R9 stated separately, and for TM-30's Rf and Rg, which use 99 samples and report fidelity and gamut as two different things.
Next to this
Colour temperature (CCT)色溫The apparent warmth or coolness of white light, in kelvin: tungsten around 3200 K, daylight around 5600 K. Co…Metamerism同色異譜Two different spectra that look identical to a human observer. The eye has three cone types, so it collapses …
Sources
- CIE 13.3 Method of measuring and specifying colour rendering properties of light sources — International Commission on Illumination primary
Understand the mechanism
Something wrong, or missing?
Every entry here is maintained by people who run shows.
Edit this entry on GitHub — one file, editable in your browser, and your handle goes on it permanently.