Color rendering index - Revision history

Voidxor: /* External links */ Rm dead external links per WP:ELDEAD.

2025-03-24T20:44:14Z

External links: Rm dead external links per WP:ELDEAD.

← Previous revision		Revision as of 20:44, 24 March 2025
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	==External links==		==External links==
	* [http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/lightsources/appendixb1.asp MATLAB script for calculating measures of light source color], [[Rensselaer Polytechnic Institute]], 2004.		* [http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/lightsources/appendixb1.asp MATLAB script for calculating measures of light source color], [[Rensselaer Polytechnic Institute]], 2004.
	* [https://web.archive.org/web/20071109105911/http://www.lightinglab.fi/teaching/217/CRI_calculation.xls Excel spreadsheet with a cornucopia of data], Lighting Laboratory of the [[Helsinki University of Technology]] (Note: Cell contents in both sheets are password protected. It may be possible to unlock the individual worksheets using AAAAAAABABB/)
	* [http://stacks.iop.org/0026-1394/46/704 Uncertainty evaluation for measurement of LED colour<!-- Should be Colour not Colour, it's part of an article title, do not "correct" it--> , Metrologia]		* [http://stacks.iop.org/0026-1394/46/704 Uncertainty evaluation for measurement of LED colour<!-- Should be Colour not Colour, it's part of an article title, do not "correct" it--> , Metrologia]
	* [http://www1.eere.energy.gov/buildings/ssl/cri_leds.html Color Rendering Index and LEDs], [http://www.eere.energy.gov/ United States Department of Energy, Office of Energy Efficiency and Renewable Energy (EERE)][bad link]		* [http://www1.eere.energy.gov/buildings/ssl/cri_leds.html Color Rendering Index and LEDs], [http://www.eere.energy.gov/ United States Department of Energy, Office of Energy Efficiency and Renewable Energy (EERE)][bad link]
		⚫	* [http://www.edaphic.com.au/knowledge-base/articles/light-articles/ What is the difference between CRI and CQS?], Edaphic Scientific Knowledge Base
	* [https://web.archive.org/web/20110718171338/http://www.lrc.rpi.edu/programs/solidstate/assist/recommends/lightcolor.asp Alliance for Solid State Illumination Systems and Technologies, Color Rendering]
⚫	* [http://www.edaphic.com.au/knowledge-base/articles/light-articles/ What is the difference between CRI and CQS?] ~~{{Webarchive\|url=https://web.archive.org/web/20150718064746/http://www.edaphic.com.au/knowledge-base/articles/light-articles/ \|date=July 18, 2015 }}~~, Edaphic Scientific Knowledge Base
	* [https://www.lumens.com/light-bulb-facts/color-rendering-index.html Understanding color rendering index for lighting], Lumens		* [https://www.lumens.com/light-bulb-facts/color-rendering-index.html Understanding color rendering index for lighting], Lumens

Voidxor: script-assisted date audit and style fixes per MOS:NUM

2025-03-24T20:39:41Z

script-assisted date audit and style fixes per MOS:NUM

Show changes

Voidxor: American English

2025-03-24T19:46:02Z

American English

← Previous revision		Revision as of 19:46, 24 March 2025
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	{{Short description\|Measure of ability of a light source to reproduce colors in comparison with a standard light source}}		{{Short description\|Measure of ability of a light source to reproduce colors in comparison with a standard light source}}
	{{~~use~~ American English\|date=~~January~~ ~~2022~~}}		{{Use American English\|date=March 2025}}
	{{use mdy dates\|date=September 2020\|cs1-dates=ly}}		{{use mdy dates\|date=September 2020\|cs1-dates=ly}}
	[[File:Simple spectroscope.jpg\|thumb\|upright=1.35\|right\|Emitted light spectrum determines the CRI of the lamp. An incandescent lamp (middle image) has a continuous spectrum and therefore a higher CRI than a fluorescent lamp (lower image). The top image shows the setup of the demonstration from above.]]		[[File:Simple spectroscope.jpg\|thumb\|upright=1.35\|right\|Emitted light spectrum determines the CRI of the lamp. An incandescent lamp (middle image) has a continuous spectrum and therefore a higher CRI than a fluorescent lamp (lower image). The top image shows the setup of the demonstration from above.]]
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	\| TCS01		\| TCS01
	\| 7,5 R 6/4		\| 7,5 R 6/4
	\| Light ~~greyish~~ red		\| Light grayish red
	\| style="background:#e8a7b0;" \|		\| style="background:#e8a7b0;" \|
	\|-		\|-
	\| TCS02		\| TCS02
	\| 5 Y 6/4		\| 5 Y 6/4
	\| Dark ~~greyish~~ yellow		\| Dark grayish yellow
	\| style="background:#ccb184;" \|		\| style="background:#ccb184;" \|
	\|-		\|-
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	* {{cite conference \|title=Optical metrology for LEDs and solid state lighting \|last=Ohno \|first=Yoshi \|series=Fifth Symposium Optics in Industry \|year=2006 \|book-title=Proceedings of SPIE: Fifth Symposium Optics in Industry \|volume=6046 \|pages=604625-1–604625-8 \|editor=E. Rosas \|editor2=R. Cardoso \|editor3=J.C. Bermudez \|editor4=O. Barbosa-Garcia \|url=http://www.nist.gov/manuscript-publication-search.cfm?pub_id=840989 \|doi=10.1117/12.674617 \|bibcode=2006SPIE.6046E..25O}}		* {{cite conference \|title=Optical metrology for LEDs and solid state lighting \|last=Ohno \|first=Yoshi \|series=Fifth Symposium Optics in Industry \|year=2006 \|book-title=Proceedings of SPIE: Fifth Symposium Optics in Industry \|volume=6046 \|pages=604625-1–604625-8 \|editor=E. Rosas \|editor2=R. Cardoso \|editor3=J.C. Bermudez \|editor4=O. Barbosa-Garcia \|url=http://www.nist.gov/manuscript-publication-search.cfm?pub_id=840989 \|doi=10.1117/12.674617 \|bibcode=2006SPIE.6046E..25O}}
	* {{citation\|first1=Nicolas\|last1=Pousset\|first2=Gael\|last2=Obein\|first3=Annick\|last3=Razet\|title=Visual experiment on LED lighting quality with color quality scale colored samples\|journal=Proceedings of CIE 2010: Lighting Quality and Energy Efficiency, Vienna, Austria\|year=2010\|pages=722–729 \|url=http://nicolas.pousset.pagesperso-orange.fr/Recherche/Article/CQS.pdf}}		* {{citation\|first1=Nicolas\|last1=Pousset\|first2=Gael\|last2=Obein\|first3=Annick\|last3=Razet\|title=Visual experiment on LED lighting quality with color quality scale colored samples\|journal=Proceedings of CIE 2010: Lighting Quality and Energy Efficiency, Vienna, Austria\|year=2010\|pages=722–729 \|url=http://nicolas.pousset.pagesperso-orange.fr/Recherche/Article/CQS.pdf}}
	* {{~~citation~~\|first=János\|last=Schanda\|~~contribution~~=The ~~concept~~ of ~~colour~~ ~~rendering~~ ~~revisited~~\|~~title~~=First European Conference on Color in Graphics Imaging and Vision\|location=Poitiers, France\|date=April 2–5, 2002 \|url=http://www.knt.vein.hu/staff/schandaj/SJCV-Publ-2005/462.pdf\|archive-url=https://web.archive.org/web/20110721113839/http://www.knt.vein.hu/staff/schandaj/SJCV-Publ-2005/462.pdf \|archive-date=July 21, 2011}}		* {{cite conference \|first=János \|last=Schanda \|title=The Concept of Colour Rendering Revisited \|conference=First European Conference on Color in Graphics Imaging and Vision \|location=Poitiers, France \|date=April 2–5, 2002 \|url=http://www.knt.vein.hu/staff/schandaj/SJCV-Publ-2005/462.pdf \|archive-url=https://web.archive.org/web/20110721113839/http://www.knt.vein.hu/staff/schandaj/SJCV-Publ-2005/462.pdf \|archive-date=July 21, 2011 }}
	* {{cite conference \|first1=János \|last1=Schanda \|first2=Norbert \|last2=Sándor \|~~year~~=2003 \|title=Colour rendering, past – present – future \|pages=76–85 \|conference=International Lighting and Colour Conference, Cape Town, South Africa, Nov 2–5, 2003}}		* {{cite conference \|first1=János \|last1=Schanda \|first2=Norbert \|last2=Sándor \|date=2003 \|title=Colour rendering, past – present – future \|pages=76–85 \|conference=International Lighting and Colour Conference, Cape Town, South Africa, Nov 2–5, 2003 }}
	* {{citation\|first=William A.\|last=Thornton\|title=Color-Rendering Capability of Commercial Lamps\|journal=[[Applied Optics]]\|year=1972\|volume=11\|issue=5\|pages=1078–1086\|doi=10.1364/AO.11.001078\|pmid=20119099\|bibcode=1972ApOpt..11.1078T}}		* {{citation\|first=William A.\|last=Thornton\|title=Color-Rendering Capability of Commercial Lamps\|journal=[[Applied Optics]]\|year=1972\|volume=11\|issue=5\|pages=1078–1086\|doi=10.1364/AO.11.001078\|pmid=20119099\|bibcode=1972ApOpt..11.1078T}}
	* {{citation\|first=K.A.G.\|last=Smet\|title=Correlation between color quality metric predictions and visual appreciation of light sources\|journal=[[Optics Express]]\|year=2011\|volume=19\|issue=9\|pages=8151–8166 \|doi=10.1364/oe.19.008151\|pmid=21643065\|bibcode=2011OExpr..19.8151S\|doi-access=free}}		* {{citation\|first=K.A.G.\|last=Smet\|title=Correlation between color quality metric predictions and visual appreciation of light sources\|journal=[[Optics Express]]\|year=2011\|volume=19\|issue=9\|pages=8151–8166 \|doi=10.1364/oe.19.008151\|pmid=21643065\|bibcode=2011OExpr..19.8151S\|doi-access=free}}

Error9900: Hyphenate black-body radiator for internal consistency; add links to pages for "black body" and "black-body radiation" to references that aren't already close to a link to one of those pages

2025-02-21T19:34:08Z

Hyphenate black-body radiator for internal consistency; add links to pages for "black body" and "black-body radiation" to references that aren't already close to a link to one of those pages

← Previous revision		Revision as of 19:34, 21 February 2025
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	==Test method==		==Test method==

	The CRI is calculated by comparing the color rendering of the test source to that of a "perfect" source, which is a black body radiator for sources with correlated color temperatures under 5000 K, and a phase of daylight otherwise (e.g., [[CIE Standard Illuminant D65\|D65]]). [[Chromatic adaptation]] should be performed so that like quantities are compared. The ''Test Method'' (also called ''Test Sample Method'' or ''Test Color Method'') needs only [[colorimetric]], rather than [[spectrophotometric]], information.<ref name="CIE1995"/><ref>		The CRI is calculated by comparing the color rendering of the test source to that of a "perfect" source, which is a [[black-body radiator]] for sources with correlated color temperatures under 5000 K, and a phase of daylight otherwise (e.g., [[CIE Standard Illuminant D65\|D65]]). [[Chromatic adaptation]] should be performed so that like quantities are compared. The ''Test Method'' (also called ''Test Sample Method'' or ''Test Color Method'') needs only [[colorimetric]], rather than [[spectrophotometric]], information.<ref name="CIE1995"/><ref>
	{{citation		{{citation
	\|title=Color rendering of light sources: CIE method of specification and its application		\|title=Color rendering of light sources: CIE method of specification and its application
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	===Chromatic adaptation===		===Chromatic adaptation===
	[[File:CIE CRI TCS under FL4.svg\|thumb\|Chromatic adaptation of TCSs lit by CIE FL4 (short, black vectors, to indicate before and after) to a black body of 2940 K (cyan circles)]]		[[File:CIE CRI TCS under FL4.svg\|thumb\|Chromatic adaptation of TCSs lit by CIE FL4 (short, black vectors, to indicate before and after) to a [[black body]] of 2940 K (cyan circles)]]

	{{harvtxt\|CIE\|1995}} uses this von Kries chromatic transform equation to find the [[corresponding color]] (''u''<sub>''c'',''i''</sub>, ''v''<sub>''c'',''i''</sub>) for each sample. The mixed subscripts (''t'', ''i'') refer to the [[inner product]] of the test illuminant spectrum and the spectral reflexivity of sample ''i'':		{{harvtxt\|CIE\|1995}} uses this von Kries chromatic transform equation to find the [[corresponding color]] (''u''<sub>''c'',''i''</sub>, ''v''<sub>''c'',''i''</sub>) for each sample. The mixed subscripts (''t'', ''i'') refer to the [[inner product]] of the test illuminant spectrum and the spectral reflexivity of sample ''i'':
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	* [[#New test color samples\|A new set of test color samples]]		* [[#New test color samples\|A new set of test color samples]]
	* Six reference illuminants: D65, D50, black bodies of 4200 K, 3450 K, 2950 K, and 2700 K.		* Six reference illuminants: D65, D50, [[black bodies]] of 4200 K, 3450 K, 2950 K, and 2700 K.
	* A new chromatic adaptation transform: CIECAT94.		* A new chromatic adaptation transform: CIECAT94.
	* Color difference evaluation in CIELAB.		* Color difference evaluation in CIELAB.
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	<math display="block">v = \frac{6 \times 0.4031}{-2 \times 0.4402 + 12 \times 0.4031 + 3} = 0.3477.</math>		<math display="block">v = \frac{6 \times 0.4031}{-2 \times 0.4402 + 12 \times 0.4031 + 3} = 0.3477.</math>

	[[Image:CIE illuminant F4 and a blackbody of 2938K.svg\|thumb\|Relative SPD of FL4 and a black body of equal CCT. Not normalized.]]		[[Image:CIE illuminant F4 and a blackbody of 2938K.svg\|thumb\|Relative SPD of FL4 and a [[black body]] of equal CCT. Not normalized.]]

	Examining the CIE 1960 UCS reveals this point to be closest to 2938 K on the Planckian locus, which has a coordinate of (0.2528, 0.3484). The distance of the test point to the locus is under the limit (5.4×10<sup>−3</sup>), so we can continue the procedure, assured of a meaningful result:		Examining the CIE 1960 UCS reveals this point to be closest to 2938 K on the Planckian locus, which has a coordinate of (0.2528, 0.3484). The distance of the test point to the locus is under the limit (5.4×10<sup>−3</sup>), so we can continue the procedure, assured of a meaningful result:
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	[[File:CIE CRI TCS under FL4.svg\|thumb\|upright=2.8\|center\|The cyan circles indicate the TCS under the ''reference'' illuminant. The short, black, vectors indicate the TCS under the ''test'' illuminant, before and after chromatic adaptation transformation (CAT). (The vectors are short because the white points are close.) The post-CAT end of the vector lies NW, mirroring the chromaticity vector between the reference and test illuminants.		[[File:CIE CRI TCS under FL4.svg\|thumb\|upright=2.8\|center\|The cyan circles indicate the TCS under the ''reference'' illuminant. The short, black, vectors indicate the TCS under the ''test'' illuminant, before and after chromatic adaptation transformation (CAT). (The vectors are short because the white points are close.) The post-CAT end of the vector lies NW, mirroring the chromaticity vector between the reference and test illuminants.

	The special CRIs are reflected in the length of the dotted lines linking the chromaticities of the samples under the reference and chromatically adapted test illuminants, respectively. Short distances, as in the case of TCS3, result in a high special CRI (87.9), whereas long distances, as in the case of TCS8, result in a low special CRI (10.4). In simpler terms, TCS3 reproduces better under FL4 than does TCS8 (relative to a black body).]]		The special CRIs are reflected in the length of the dotted lines linking the chromaticities of the samples under the reference and chromatically adapted test illuminants, respectively. Short distances, as in the case of TCS3, result in a high special CRI (87.9), whereas long distances, as in the case of TCS8, result in a low special CRI (10.4). In simpler terms, TCS3 reproduces better under FL4 than does TCS8 (relative to a [[black body]]).]]

	== Typical values ==		== Typical values ==

Error9900: /* Typical values */ Add link to the "black-body radiation" article, and hyphenate "black-body" for internal consistency.

2025-02-21T18:55:05Z

Typical values: Add link to the "black-body radiation" article, and hyphenate "black-body" for internal consistency.

← Previous revision		Revision as of 18:55, 21 February 2025
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	\|}		\|}

	A reference source, such as ~~blackbody~~ radiation, is defined as having a CRI of 100. This is why [[incandescent lamp]]s have that rating, as they are, in effect, almost ~~blackbody~~ radiators.<ref>{{Cite web \|last=Fixtures \|first=Access \|date=2017-01-26 \|title=CRI: What Is the Color Rendering Index? Is It Accurate? \|url=https://www.accessfixtures.com/color-rendering-index/ \|access-date=2022-03-13 \|website=Access Fixtures \|language=en-US}}</ref> The best possible faithfulness to a reference is specified by CRI = 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.		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=2017-01-26 \|title=CRI: What Is the Color Rendering Index? Is It Accurate? \|url=https://www.accessfixtures.com/color-rendering-index/ \|access-date=2022-03-13 \|website=Access Fixtures \|language=en-US}}</ref> The best possible faithfulness to a reference is specified by CRI = 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.

	== Special value: R9 ==		== Special value: R9 ==

Chris Capoccia at 14:00, 8 February 2025

2025-02-08T14:00:56Z

← Previous revision		Revision as of 14:00, 8 February 2025
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	Numerically, the highest possible CIE R<sub>a</sub> value is 100 and would only be given to a source whose [[spectrum]] is identical to [[Solar spectrum\|the spectrum of daylight]], very close to that of a [[black body]] (incandescent lamps are effectively black bodies), dropping to negative values for some light sources. [[Low-pressure sodium light]]ing has a negative CRI; [[fluorescent light]]s range from about 50 for the basic types, up to about 98 for the best multi-phosphor type. Typical white-color [[LEDs]] have a CRI of 80 or more, while some manufacturers claim that their LEDs achieve a CRI of up to 98.<ref>{{Cite web \|url=http://www.ledengin.com/files/products/LZC/LZC-00GW00.pdf \|title=LZC-00GW00 Data Sheet \|date=March 16, 2015 \|website=ledengin.com \|publisher=LED ENGIN \|archive-url=https://web.archive.org/web/20170105235216/http://www.ledengin.com/files/products/LZC/LZC-00GW00.pdf \|archive-date=January 5, 2017 }}</ref>		Numerically, the highest possible CIE R<sub>a</sub> value is 100 and would only be given to a source whose [[spectrum]] is identical to [[Solar spectrum\|the spectrum of daylight]], very close to that of a [[black body]] (incandescent lamps are effectively black bodies), dropping to negative values for some light sources. [[Low-pressure sodium light]]ing has a negative CRI; [[fluorescent light]]s range from about 50 for the basic types, up to about 98 for the best multi-phosphor type. Typical white-color [[LEDs]] have a CRI of 80 or more, while some manufacturers claim that their LEDs achieve a CRI of up to 98.<ref>{{Cite web \|url=http://www.ledengin.com/files/products/LZC/LZC-00GW00.pdf \|title=LZC-00GW00 Data Sheet \|date=March 16, 2015 \|website=ledengin.com \|publisher=LED ENGIN \|archive-url=https://web.archive.org/web/20170105235216/http://www.ledengin.com/files/products/LZC/LZC-00GW00.pdf \|archive-date=January 5, 2017 }}</ref>

	CIE R<sub>a</sub>'s ability to predict color appearance has been criticized in favor of measures based on [[color appearance model]]s, such as [[CIECAM02]] and for [[daylight]] simulators, the CIE [[metamerism index]].<ref>{{citation \|first2=János \|last2=Schanda \|first1=Norbert \|last1=Sándor \|journal=Lighting Research and Technology \|volume=38 \|issue=3 \|title=Visual colour rendering based on colour difference evaluations \|date=September 1, 2006 \|pages=225–239 \|doi=10.1191/1365782806lrt168oa ~~\|s2cid=109858508~~}}.<br />Conference version of this article:<br />{{citation \|first2=János \|last2=Schanda \|first1=Norbert \|last1=Sándor \|title=Visual colour-rendering experiments \|journal=AIC Colour '05: 10th Congress of the International Colour Association \|year=2005 \|pages=511–514 \|url=http://www.knt.vein.hu/staff/schandaj/SJCV-Publ-2005/521.pdf \|archive-url=https://web.archive.org/web/20110721114551/http://www.knt.vein.hu/staff/schandaj/SJCV-Publ-2005/521.pdf \|archive-date=2011-07-21}}</ref> CRI is not a good indicator for use in visual assessment of light sources, especially for sources below 5000 [[kelvin]] (K).<ref>{{citation		CIE R<sub>a</sub>'s ability to predict color appearance has been criticized in favor of measures based on [[color appearance model]]s, such as [[CIECAM02]] and for [[daylight]] simulators, the CIE [[metamerism index]].<ref>{{citation \|first2=János \|last2=Schanda \|first1=Norbert \|last1=Sándor \|journal=Lighting Research and Technology \|volume=38 \|issue=3 \|title=Visual colour rendering based on colour difference evaluations \|date=September 1, 2006 \|pages=225–239 \|doi=10.1191/1365782806lrt168oa }}.<br />Conference version of this article:<br />{{citation \|first2=János \|last2=Schanda \|first1=Norbert \|last1=Sándor \|title=Visual colour-rendering experiments \|journal=AIC Colour '05: 10th Congress of the International Colour Association \|year=2005 \|pages=511–514 \|url=http://www.knt.vein.hu/staff/schandaj/SJCV-Publ-2005/521.pdf \|archive-url=https://web.archive.org/web/20110721114551/http://www.knt.vein.hu/staff/schandaj/SJCV-Publ-2005/521.pdf \|archive-date=2011-07-21}}</ref> CRI is not a good indicator for use in visual assessment of light sources, especially for sources below 5000 [[kelvin]] (K).<ref>{{citation
	\| last1 = Guo		\| last1 = Guo
	\| first1= Xin		\| first1= Xin
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	\| pages = 183–199		\| pages = 183–199
	\| doi = 10.1191/1365782804li112oa		\| doi = 10.1191/1365782804li112oa
	\| s2cid= 109227871
	}}</ref><ref name="CIE1995">{{citation		}}</ref><ref name="CIE1995">{{citation
	\|author = CIE		\|author = CIE
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	{{harvtxt\|Smet\|2011}} reviewed several alternative quality metrics and compared their performance based on visual data obtained in nine psychophysical experiments. It was found that a geometric mean of the GAI index and the CIE Ra correlated best with naturalness (r=0.85), while a color quality metric based on memory colors (MCRI<ref>Smet K. A. G., Ryckaert W. R., Pointer M. R., Deconinck G., Hanselaer P. Colour Appearance Rating of Familiar Real Objects. Colour Research and Application 2011; 36(3):192–200.</ref>) correlated best for preference (''r'' = 0.88). The differences in performance of these metrics with the other tested metrics (CIE Ra; CRI-CAM02UCS; CQS; RCRI; GAI; geomean (GAI, CIE Ra); CSA; Judd Flattery; Thornton CPI; MCRI) were found to be statistically significant with ''p'' < 0.0001.<ref>Smet K. A. G., Ryckaert W. R., Pointer M. R., Deconinck G., Hanselaer P. [http://www.opticsinfobase.org/view_article.cfm?gotourl=http%3A%2F%2Fwww.opticsinfobase.org%2FDirectPDFAccess%2F3AAAA211-C63E-79CC-4E0A0772E17419BA_212731.pdf%3Fda%3D1%26id%3D212731%26seq%3D0%26mobile%3Dno&org= Correlation between color quality metric predictions and visual appreciation of light sources].</ref>		{{harvtxt\|Smet\|2011}} reviewed several alternative quality metrics and compared their performance based on visual data obtained in nine psychophysical experiments. It was found that a geometric mean of the GAI index and the CIE Ra correlated best with naturalness (r=0.85), while a color quality metric based on memory colors (MCRI<ref>Smet K. A. G., Ryckaert W. R., Pointer M. R., Deconinck G., Hanselaer P. Colour Appearance Rating of Familiar Real Objects. Colour Research and Application 2011; 36(3):192–200.</ref>) correlated best for preference (''r'' = 0.88). The differences in performance of these metrics with the other tested metrics (CIE Ra; CRI-CAM02UCS; CQS; RCRI; GAI; geomean (GAI, CIE Ra); CSA; Judd Flattery; Thornton CPI; MCRI) were found to be statistically significant with ''p'' < 0.0001.<ref>Smet K. A. G., Ryckaert W. R., Pointer M. R., Deconinck G., Hanselaer P. [http://www.opticsinfobase.org/view_article.cfm?gotourl=http%3A%2F%2Fwww.opticsinfobase.org%2FDirectPDFAccess%2F3AAAA211-C63E-79CC-4E0A0772E17419BA_212731.pdf%3Fda%3D1%26id%3D212731%26seq%3D0%26mobile%3Dno&org= Correlation between color quality metric predictions and visual appreciation of light sources].</ref>

	Dangol, et al., performed psychophysical experiments and concluded that people's judgments of naturalness and overall preference could not be predicted with a single measure, but required the joint use of a fidelity-based measure (e.g., Qp) and a gamut-based measure (e.g., Qg or GAI.).<ref>{{~~citation~~\|last1=Dangol\|first1=R.\|title=Subjective preferences and colour quality metrics of LED light sources~~\|date=December~~ ~~2013~~\|journal=Lighting Research ~~and~~ Technology\|volume=45\|issue=6\|pages=666–688\|doi=10.1177/1477153512471520~~\|issn=1477-1535\|last2=Islam\|first2=M.\|last3=Hyvärinen\|first3=M.\|last4=Bhusal\|first4=P.\|last5=Puolakka\|first5=M.\|last6=Halonen\|first6=L.\|s2cid=109981392~~}}</ref> They carried out further experiments in real offices evaluating various spectra generated for combination existing and proposed color rendering metrics.<ref>{{cite journal\|last1=Dangol\|first1=R\|last2=Islam\|first2=MS\|last3=Hyvärinen\|first3=M\|last4=Bhushal\|first4=P\|last5=Puolakka\|first5=M\|last6=Halonen\|first6=L\|year=2015\|title=User acceptance studies for LED office lighting: Preference, naturalness and colourfulness\|journal=Lighting Research & Technology\|volume=47\|pages=36–53\|doi=10.1177/1477153513514424~~\|s2cid=110803300~~}}</ref><ref>{{cite journal\|last1=Islam\|first1=MS\|last2=Dangol\|first2=R\|last3=Hyvärinen\|first3=M\|last4=Bhusal\|first4=P\|last5=Puolakka\|first5=M\|last6=Halonen\|first6=L\|year=2013\|title=User acceptance studies for LED office lighting: Lamp spectrum, spatial brightness and illuminance\|journal=Lighting Research & Technology\|volume=47\|pages=54–79\|doi=10.1177/1477153513514425~~\|s2cid=109592929~~}}</ref><ref>{{cite journal\|last1=Baniya\|first1=R. R.\|last2=Dangol\|first2=R.\|last3=Bhusal\|first3=P.\|last4=Wilm\|first4=A.\|last5=Baur\|first5=E.\|last6=Puolakka\|first6=M.\|last7=Halonen\|first7=L.\|year=2015\|title=User-acceptance studies for simplified light-emitting diode spectra\|journal=Lighting Research and Technology\|volume=47\|issue=2\|pages=177–191\|doi=10.1177/1477153513515264~~\|s2cid=112031599~~}}</ref>		Dangol, et al., performed psychophysical experiments and concluded that people's judgments of naturalness and overall preference could not be predicted with a single measure, but required the joint use of a fidelity-based measure (e.g., Qp) and a gamut-based measure (e.g., Qg or GAI.).<ref>{{cite journal \|last1=Dangol \|first1=R \|last2=Islam \|first2=M \|last3=LiSc \|first3=M Hyvärinen \|last4=Bhusal \|first4=P \|last5=Puolakka \|first5=M \|last6=Halonen \|first6=L \|title=Subjective preferences and colour quality metrics of LED light sources \|journal=Lighting Research & Technology \|date=December 2013 \|volume=45 \|issue=6 \|pages=666–688 \|doi=10.1177/1477153512471520 }}</ref> They carried out further experiments in real offices evaluating various spectra generated for combination existing and proposed color rendering metrics.<ref>{{cite journal\|last1=Dangol\|first1=R\|last2=Islam\|first2=MS\|last3=Hyvärinen\|first3=M\|last4=Bhushal\|first4=P\|last5=Puolakka\|first5=M\|last6=Halonen\|first6=L\|year=2015\|title=User acceptance studies for LED office lighting: Preference, naturalness and colourfulness\|journal=Lighting Research & Technology\|volume=47\|pages=36–53\|doi=10.1177/1477153513514424 }}</ref><ref>{{cite journal\|last1=Islam\|first1=MS\|last2=Dangol\|first2=R\|last3=Hyvärinen\|first3=M\|last4=Bhusal\|first4=P\|last5=Puolakka\|first5=M\|last6=Halonen\|first6=L\|year=2013\|title=User acceptance studies for LED office lighting: Lamp spectrum, spatial brightness and illuminance\|journal=Lighting Research & Technology\|volume=47\|pages=54–79\|doi=10.1177/1477153513514425 }}</ref><ref>{{cite journal\|last1=Baniya\|first1=R. R.\|last2=Dangol\|first2=R.\|last3=Bhusal\|first3=P.\|last4=Wilm\|first4=A.\|last5=Baur\|first5=E.\|last6=Puolakka\|first6=M.\|last7=Halonen\|first7=L.\|year=2015\|title=User-acceptance studies for simplified light-emitting diode spectra\|journal=Lighting Research and Technology\|volume=47\|issue=2\|pages=177–191\|doi=10.1177/1477153513515264 }}</ref>

	Due to the criticisms of CRI many researchers have developed alternative metrics, though relatively few of them have had wide adoption.		Due to the criticisms of CRI many researchers have developed alternative metrics, though relatively few of them have had wide adoption.
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	* {{citation\|first=William A.\|last=Thornton\|title=Color-Rendering Capability of Commercial Lamps\|journal=[[Applied Optics]]\|year=1972\|volume=11\|issue=5\|pages=1078–1086\|doi=10.1364/AO.11.001078\|pmid=20119099\|bibcode=1972ApOpt..11.1078T}}		* {{citation\|first=William A.\|last=Thornton\|title=Color-Rendering Capability of Commercial Lamps\|journal=[[Applied Optics]]\|year=1972\|volume=11\|issue=5\|pages=1078–1086\|doi=10.1364/AO.11.001078\|pmid=20119099\|bibcode=1972ApOpt..11.1078T}}
	* {{citation\|first=K.A.G.\|last=Smet\|title=Correlation between color quality metric predictions and visual appreciation of light sources\|journal=[[Optics Express]]\|year=2011\|volume=19\|issue=9\|pages=8151–8166 \|doi=10.1364/oe.19.008151\|pmid=21643065\|bibcode=2011OExpr..19.8151S\|doi-access=free}}		* {{citation\|first=K.A.G.\|last=Smet\|title=Correlation between color quality metric predictions and visual appreciation of light sources\|journal=[[Optics Express]]\|year=2011\|volume=19\|issue=9\|pages=8151–8166 \|doi=10.1364/oe.19.008151\|pmid=21643065\|bibcode=2011OExpr..19.8151S\|doi-access=free}}
	* {{citation\|first1=R.\|last1=Dangol\|first2=M.\|last2=Islam\|first3=M.\|last3=Hyvärinen\|first4=P.\|last4=Bhusal \|first5=M.\|last5=Puolakka\|first6=L.\|last6=Halonen\|title=Subjective preferences and colour quality metrics of LED light sources \|journal=Lighting Research and Technology\|volume=45\|issue=6\|pages=666–688\|date=December 2013 \|issn=1477-1535\|doi=10.1177/1477153512471520~~\|s2cid=109981392~~}}		* {{citation\|first1=R.\|last1=Dangol\|first2=M.\|last2=Islam\|first3=M.\|last3=Hyvärinen\|first4=P.\|last4=Bhusal \|first5=M.\|last5=Puolakka\|first6=L.\|last6=Halonen\|title=Subjective preferences and colour quality metrics of LED light sources \|journal=Lighting Research and Technology\|volume=45\|issue=6\|pages=666–688\|date=December 2013 \|issn=1477-1535\|doi=10.1177/1477153512471520 }}
	* {{citation\|first1=M.S.\|last1=Islam\|first2=R.\|last2=Dangol\|first3=M.\|last3=Hyvärinen\|first4=P.\|last4=Bhusal \|first5=M.\|last5=Puolakka\|first6=L.\|last6=Halonen\|title=User preferences for LED lighting in terms of light spectrum \|journal=Lighting Research and Technology\|volume=45\|issue=6\|pages=641–665\|date=December 2013 \|issn=1477-1535\|doi=10.1177/1477153513475913~~\|s2cid=110762470~~}}		* {{citation\|first1=M.S.\|last1=Islam\|first2=R.\|last2=Dangol\|first3=M.\|last3=Hyvärinen\|first4=P.\|last4=Bhusal \|first5=M.\|last5=Puolakka\|first6=L.\|last6=Halonen\|title=User preferences for LED lighting in terms of light spectrum \|journal=Lighting Research and Technology\|volume=45\|issue=6\|pages=641–665\|date=December 2013 \|issn=1477-1535\|doi=10.1177/1477153513475913 }}
	* {{cite journal \|last1=Baniya \|first1=R.R. \|last2=Dangol \|first2=R. \|last3=Bhusal \|first3=P. \|last4=Wilm \|first4=A. \|last5=Baur \|first5=E. \|last6=Puolakka \|first6=M. \|last7=Halonen \|first7=L. \|year=2015\| title=User-acceptance studies for simplified light-emitting diode spectra ~~\|url= http://lrt.sagepub.com/content/47/2/177~~ \|journal=Lighting Research and Technology \|volume=47 \|issue=2\| pages=177–191 \|doi= 10.1177/1477153513515264 ~~\|s2cid= 112031599~~}}		* {{cite journal \|last1=Baniya \|first1=R.R. \|last2=Dangol \|first2=R. \|last3=Bhusal \|first3=P. \|last4=Wilm \|first4=A. \|last5=Baur \|first5=E. \|last6=Puolakka \|first6=M. \|last7=Halonen \|first7=L. \|year=2015\| title=User-acceptance studies for simplified light-emitting diode spectra \|journal=Lighting Research and Technology \|volume=47 \|issue=2\| pages=177–191 \|doi= 10.1177/1477153513515264 }}
	* {{cite journal \|last1=Dangol \|first1=R. \|last2=Islam \|first2=M. \|last3=Hyvärinen \|first3=M. \|last4=Bhusal \|first4=P. \|last5=Puolakka \|first5=M. \|last6=Halonen \|first6=L. \|year=2015\| title=User acceptance studies for LED office lighting: Preference, naturalness and colourfulness \|journal=Lighting Research and Technology \|volume=47 \|issue=1\| pages=36–53 \|doi= 10.1177/1477153513514424 ~~\|s2cid= 110803300~~}}		* {{cite journal \|last1=Dangol \|first1=R. \|last2=Islam \|first2=M. \|last3=Hyvärinen \|first3=M. \|last4=Bhusal \|first4=P. \|last5=Puolakka \|first5=M. \|last6=Halonen \|first6=L. \|year=2015\| title=User acceptance studies for LED office lighting: Preference, naturalness and colourfulness \|journal=Lighting Research and Technology \|volume=47 \|issue=1\| pages=36–53 \|doi= 10.1177/1477153513514424 }}
	* {{cite journal \|last1=Islam \|first1=M. \|last2=Dangol \|first2=R. \|last3=Hyvärinen \|first3=M. \|last4=Bhusal \|first4=P. \|last5=Puolakka \|first5=M. \|last6=Halonen \|first6=L. \|year=2013\| title=User acceptance studies for LED office lighting: lamp spectrum, spatial brightness and illuminance level ~~\|url= http://lrt.sagepub.com/content/47/1/54~~ \|journal=Lighting Research and Technology \|volume=47 \|issue=1\| pages=54–79 \|doi= 10.1177/1477153513514425 ~~\|s2cid= 109592929~~}}		* {{cite journal \|last1=Islam \|first1=M. \|last2=Dangol \|first2=R. \|last3=Hyvärinen \|first3=M. \|last4=Bhusal \|first4=P. \|last5=Puolakka \|first5=M. \|last6=Halonen \|first6=L. \|year=2013\| title=User acceptance studies for LED office lighting: lamp spectrum, spatial brightness and illuminance level \|journal=Lighting Research and Technology \|volume=47 \|issue=1\| pages=54–79 \|doi= 10.1177/1477153513514425 }}

	==External links==		==External links==

Chris Capoccia: failed verification. needs specific citation to article/chapter and not a big category search results

2025-02-08T13:59:02Z

failed verification. needs specific citation to article/chapter and not a big category search results

← Previous revision		Revision as of 13:59, 8 February 2025
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	\|}		\|}

	A reference source, such as blackbody radiation, is defined as having a CRI of 100. This is why [[incandescent lamp]]s have that rating, as they are, in effect, almost blackbody radiators.<ref>{{Cite web \|title=Blackbody Radiator - an overview {{!}} ScienceDirect Topics \|url=https://www.sciencedirect.com/topics/engineering/blackbody-radiator \|access-date=2022-03-13 \|website=www.sciencedirect.com}}</ref><ref>{{Cite web \|last=Fixtures \|first=Access \|date=2017-01-26 \|title=CRI: What Is the Color Rendering Index? Is It Accurate? \|url=https://www.accessfixtures.com/color-rendering-index/ \|access-date=2022-03-13 \|website=Access Fixtures \|language=en-US}}</ref> The best possible faithfulness to a reference is specified by CRI = 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.		A reference source, such as blackbody radiation, is defined as having a CRI of 100. This is why [[incandescent lamp]]s have that rating, as they are, in effect, almost blackbody radiators.<ref>{{Cite web \|last=Fixtures \|first=Access \|date=2017-01-26 \|title=CRI: What Is the Color Rendering Index? Is It Accurate? \|url=https://www.accessfixtures.com/color-rendering-index/ \|access-date=2022-03-13 \|website=Access Fixtures \|language=en-US}}</ref> The best possible faithfulness to a reference is specified by CRI = 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.

	== Special value: R9 ==		== Special value: R9 ==

Doomhope: new key for Category:Color: "rendering index" using HotCat

2025-01-30T07:53:55Z

new key for Category:Color: "rendering index" using HotCat

← Previous revision		Revision as of 07:53, 30 January 2025
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	{{DEFAULTSORT:Color Rendering Index}}		{{DEFAULTSORT:Color Rendering Index}}
	[[Category:Color]]		[[Category:Color\|rendering index]]
	[[Category:Lighting]]		[[Category:Lighting]]

185.89.38.28: Removed utterly BS reference

2024-07-15T03:14:59Z

Removed **utterly BS** reference

← Previous revision		Revision as of 03:14, 15 July 2024
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	[[File:AmbientLED.png\|thumb\|upright=1.35\|right\|Color rendering index shown as color accuracy]]		[[File:AmbientLED.png\|thumb\|upright=1.35\|right\|Color rendering index shown as color accuracy]]

	A '''color rendering index''' ('''CRI''') is a quantitative measure of the ability of a [[light source]] to reveal the [[color]]s of various objects faithfully in comparison with a natural or standard light source. Light sources with a high CRI are desirable in color-critical applications such as [[Neonatal nursing\|neonatal care]]<ref>{{Cite web \|title=Neonatal intensive care unit lighting: Update and Recommendations \|url=https://www.researchgate.net/publication/305334032}}</ref> and [[Conservation and restoration of cultural property\|art restoration]].		A '''color rendering index''' ('''CRI''') is a quantitative measure of the ability of a [[light source]] to reveal the [[color]]s of various objects faithfully in comparison with a natural or standard light source.

	''[[Color rendering]]'', as defined by the [[International Commission on Illumination]] (CIE), is the effect of an [[Light#Light sources\|illuminant]] on the color appearance of objects by conscious or subconscious comparison with their color appearance under a reference or [[standard illuminant]].<ref>{{cite web \|url=http://www.cie.co.at/publ/abst/17-4-89.html \|title=CIE 17.4-1987 International Lighting Vocabulary \|access-date=2008-02-19 \|archive-url=https://web.archive.org/web/20100227034508/http://www.cie.co.at/publ/abst/17-4-89.html \|archive-date=2010-02-27 }}</ref>		''[[Color rendering]]'', as defined by the [[International Commission on Illumination]] (CIE), is the effect of an [[Light#Light sources\|illuminant]] on the color appearance of objects by conscious or subconscious comparison with their color appearance under a reference or [[standard illuminant]].<ref>{{cite web \|url=http://www.cie.co.at/publ/abst/17-4-89.html \|title=CIE 17.4-1987 International Lighting Vocabulary \|access-date=2008-02-19 \|archive-url=https://web.archive.org/web/20100227034508/http://www.cie.co.at/publ/abst/17-4-89.html \|archive-date=2010-02-27 }}</ref>

InternetArchiveBot: Rescuing 1 sources and tagging 0 as dead.) #IABot (v2.0.9.5

2023-12-17T10:29:29Z

Rescuing 1 sources and tagging 0 as dead.) #IABot (v2.0.9.5

← Previous revision		Revision as of 10:29, 17 December 2023
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	* [http://www1.eere.energy.gov/buildings/ssl/cri_leds.html Color Rendering Index and LEDs], [http://www.eere.energy.gov/ United States Department of Energy, Office of Energy Efficiency and Renewable Energy (EERE)][bad link]		* [http://www1.eere.energy.gov/buildings/ssl/cri_leds.html Color Rendering Index and LEDs], [http://www.eere.energy.gov/ United States Department of Energy, Office of Energy Efficiency and Renewable Energy (EERE)][bad link]
	* [https://web.archive.org/web/20110718171338/http://www.lrc.rpi.edu/programs/solidstate/assist/recommends/lightcolor.asp Alliance for Solid State Illumination Systems and Technologies, Color Rendering]		* [https://web.archive.org/web/20110718171338/http://www.lrc.rpi.edu/programs/solidstate/assist/recommends/lightcolor.asp Alliance for Solid State Illumination Systems and Technologies, Color Rendering]
	* [http://www.edaphic.com.au/knowledge-base/articles/light-articles/ What is the difference between CRI and CQS?], Edaphic Scientific Knowledge Base		* [http://www.edaphic.com.au/knowledge-base/articles/light-articles/ What is the difference between CRI and CQS?] {{Webarchive\|url=https://web.archive.org/web/20150718064746/http://www.edaphic.com.au/knowledge-base/articles/light-articles/ \|date=2015-07-18 }}, Edaphic Scientific Knowledge Base
	* [https://www.lumens.com/light-bulb-facts/color-rendering-index.html Understanding color rendering index for lighting], Lumens		* [https://www.lumens.com/light-bulb-facts/color-rendering-index.html Understanding color rendering index for lighting], Lumens