Editing Color rendering index (section)

== Typical values ==
{{unreferenced section|date=November 2021}}
{| class="wikitable" style="float:right; margin:5px;"
|-
! Light source
! CCT (K)
! CRI R<sub>a</sub>
|-
| [[Sodium-vapor lamp#Low-pressure sodium|Low-pressure sodium]] (LPS/SOX)
| 1800
| −44
|-
| Clear [[Mercury-vapor lamp|mercury-vapor]]
| 6410
| 17
|-
| [[Sodium-vapor lamp#High-pressure sodium|High-pressure sodium]] (HPS/SON)
| 2100
| 24
|-
| Coated mercury-vapor
| 3600
| 49
|-
| Halophosphate warm-white [[Fluorescent lamp|fluorescent]]
| 2940
| 51
|-
| Halophosphate cool-white fluorescent
| 4230
| 64
|-
| Tri-phosphor warm-white fluorescent
| 2940
| 73
|-
| Halophosphate cool-daylight fluorescent
| 6430
| 76
|-
| [[w:Sodium-vapor lamp|"White" SON]]
| 2700
| 82
|-
| Standard [[LED]] Lamp
| 2700–5000
| 83
|-
| Quartz [[Metal-halide lamp|metal halide]]
| 4200
| 85
|-
| Tri-phosphor cool-white [[Fluorescent lamp|fluorescent]]
| 4080
| 89
|-
| High-CRI [[LED]] lamp (blue LED)
| 2700–5000
| 95
|-
| [[Ceramic discharge metal-halide lamp]]
| 5400
| 96
|-
| Ultra-high-CRI [[LED]] lamp (violet LED)
| 2700–5000
| 99
|-
| [[Incandescent light bulb|Incandescent]]/[[Halogen lamp|halogen]] bulb
| 3200
| 100
|}

A reference source, such as [[black-body radiation]], is defined as having a CRI of 100. This is why [[incandescent lamp]]s have that rating, as they are, in effect, almost black-body radiators.<ref>{{Cite web |last=Fixtures |first=Access |date=January 26, 2017 |title=CRI: What Is the Color Rendering Index? Is It Accurate? |url=https://www.accessfixtures.com/color-rendering-index/ |access-date=March 13, 2022 |website=Access Fixtures |language=en-US}}</ref> The best possible faithfulness to a reference is specified by CRI&nbsp;= 100, while the very poorest is specified by a CRI below zero. A high CRI by itself does not imply a good rendition of color, because the reference itself may have an imbalanced SPD if it has an extreme color temperature.