IES TM-30-15 Evaluating Light Source Color Rendition
"Original"
"CRI = 80" Desaturated
"CRI = 80" Saturated
More metrics Color Fidelity Color Discrimination Color Preference
Metrics/Measures R f (IES TM-30-15) R g (IES TM-30-15) CRI R a (CIE13.3-1995) CRI R 9 (CIE13.3-1995) CCT u'v' D uv Criteria 80 0 2700 K 5000 K 0.007 Standards ANSI C78.377 ANSI/IES RP-1-12 ISO 8995-1 (CIE S 008) Design Guidance IES DG-1 TM-30 is a method that includes several related measures. TM-30 is not a required standard, and does not provide design guidance or criteria.
IES Method for Color Rendition Color Fidelity Color Gamut Graphics The accurate rendition of color so that they appear as they would under familiar (reference) illuminants Fidelity Index (R f ) (0-100) The average level of saturation relative to familiar (reference) illuminants. Gamut Index (R g ) ~60-140 when R f > 60 Visual description of hue and saturation changes. Color Vector Graphic
Samples
Uniformity
Fidelity Index: R f 0 10 20 30 40 a' Reference Source Test Source Average similarity in appearance of test and reference sources Analogous to CIE R a, greater accuracy Scores 0 to 100 Scale similar to CIE R a, but high scores harder to achieve Equal weight to all directions of shift Should not be expected to correlate with any single object
Relative Gamut Index: R g b' 40 30 20 10 0-10 -20-30 -40 7 8 9 10 6 11 5 12-40 -30-20 -10 0 10 20 30 40 a' 4 13 3 14 2 1 16 15 40 30 20 10 b' 0-10 -20-30 -40-40 -30-20 -10 0 10 20 30 40 a' An R g value greater than 100 indicates an average increase in saturation and an R g value less than 100 indicates an average decrease in saturation.
Limits
Color Vector Graphic Gamut is not a dimension of perception. It is best interpreted with reference to a complementary graphic. Color Vector Graphic Color Distortion Graphic 380 430 480 530 580 630 680 730 780 R f = 81 R g = 101 CCT = 2496 K R a = 88 (Source No. 286)
R f, R g and Color Vector Graphic CCT = 3500 K, R f = 100, R g = 100 140 130 120 110 R g 100 90 80 70 60 50 60 70 80 90 100 R f
R f, R g and Color Vector Graphic CCT = 3500 K, R f = 65, R g = 115 140 130 120 110 R g 100 90 80 70 60 50 60 70 R f 80 90 100
R f, R g and Color Vector Graphic CCT = 3500 K, R f = 65, R g = 85 140 130 120 110 R g 100 90 80 70 60 50 60 70 R f 80 90 100
Halogen MR16, 3000 K R f = 99 R g = 99 R f,skin = 99 CCT D uv R a R 9 = = = = 2988 K 0.0010 99 93 380 430 480 530 580 630 680 730 780
Neodymium Incandescent R f = 86 R g = 109 R f,skin = 83 380 430 480 530 580 630 680 730 780 CCT D uv R a R 9 = = = = 2757 K -0.0048 77 15
High Pressure Sodium (Source No. 56) R f = 32 R g = 61 R f,skin = 34 CCT D uv R a R 9 = = = = 1967 K -0.0002 16-226 380 430 480 530 580 630 680 730 780 37
F32T8 835 R f = 80 R g = 102 R f,ski n = 89 380 430 480 530 580 630 680 730 780 CCT D uv R a R 9 = = = = 3480 K 0.0007 86 15
Ceramic Metal Halide, 3000 K R f = 79 R g = 100 R f,skin = 78 380 430 480 530 580 630 680 730 780 CCT D uv R a R 9 = = = = 3080 K -0.0024 84-30
Original Desaturated Red- Enhanced CRI = 95 CRI = 80 CRI = 80 R f = 93 R g = 100 R f = 78 R g = 90 R f = 78 R g = 110 40
IES R f versus CIE R a IES R f 100 95 90 85 Filament Daylight Models Narrowband Fluorescent Broadband Fluorescent HID Hybrid LED Color Mixed LED Phosphor LED 80 75 70 70 75 80 85 CIE R a 90 95 100 ~16 point spread in R f scores at R a = ~80 23
CRI = 80 + Hue Shift R f = 75, R g = 100 57
CRI = 80 - Hue Shift R f = 75, R g = 100 58
CRI = 80 Saturated R f = 75, R g = 120 59
CRI = 80 Desaturated R f = 75, R g = 80 60
Színinger-különbség számítások 1976 előtt 1976 1979 1994 2000 kb. 30 különböző CIELAB, CIELUV CMC(l:c) CIE94 CIEDE2000
Számítás E ab 2 ( a) ( b) ( L 2 ) 2 E u v ' 2 ( u') ( v') ( L) ' 2 2 http://www.kruschwitz.com/cri.htm
CIE 1994 colour difference E * 94 L * C * H ab k S k S k S L L C C H k parametric factors, industry dependent 2 2 * 2 ab S weighting functions, depend on location in colour space: H 1/ 2 S L = 1; S C = 1 + 0,045 C* ab ; S H = 1 + 0,015 C* ab
CIEDE2000 referencia paraméterek CCT D65 megvilágítás 1000 lx háttér neutrális szürke, L' = 50 megfigyelési mód közvetlen méret >4 minták elkülönítése nincs E* ab 0-5 homogén megvilágítás
CIEDE2000 #1 a' = a*(1+g) b* a* b' a' G = 0,5[1-(C* ab,m7 /(C* ab,m7 +25 7 )) 0,5 ] b' = b* C* ab,m = (C* ab,b + C* ab,s )/2
0,6 G 0,4 0,2 0 0 20 40 60 C* ab
CIEDE2000 #2 (a', b')-chroma C' = (a' 2 + b' 2 ) 0,5 (a', b')-hue-angle chroma-diference h' = tan -1 (b'/a') C' = C' b - C' s hue-difference H'= 2(C' b C' s ) 0,5 sin( h'/2) onde h' = h' b - h' s
CIEDE2000 #3 S L = 1 + 0,015(L' m -50) 2 /[20+(L' m -50) 2 ] 0,5 L' = L* L' m = (L' b +L' s )/2
S L 2,0 1,5 1,0 0,5 0,0 0 50 100 L*
CIEDE2000 #4 S C = 1 + 0,045 C' m C' m = (C' b + C' s )/2 S C 6 4 2 0 0 40 80 120 C' m
CIEDE2000 #5 S H = 1 + 0,015 C' m T T = 1-0,17 cos(h' m -30) + 0,24 cos(2h' m ) + 0,32 cos(3h' m +6) - 0,20 cos(4h' m -63) h' m = (h' b +h' s )/2
3 S H 2 1 0 0 40 80 120 C' m T
T 2 1,6 1,2 0,8 0,4 0 R Y G B 0 90 180 270 360 h'
S H 2,5 2 1,5 1 C' = 50 C' = 20 C' = 5 0,5 0 R Y G B 0 90 180 270 360 h'
CIEDE2000 #6 b* a*
R T C' H' R T = - sin(2 Q) R C Q 30 exp[ - ((h' m -275)/25) 2 ] R C = 2(C' m7 /(C' m7 + 25 7 )) 0,5
0,5 0-0,5 R Y G B 0 90 180 270 360 R T -1 C' = 5-1,5-2 C' = 20 C' = 50 h'
CIE 2000 ( L' C' H') E 00 = [( L'/k L S L ) 2 + ( C'/k C S C ) 2 + ( H' /k H S H ) 2 + R T ( C' /k C S C )( H' /k H S H )] 0,5 k L, k C, k H = faktorok
Gyakorlati összefoglaló CIEDE2000 ipari alkalmazásra lett kifejlesztve kis és közepes színkülönbségekhez jobb, mint a CMC(l:c) és a CIE94 teszt fázisban van, az eredményeket a CIE gyűjti a jövőben kiváltja majd a CMC(l:c) t az ISO szabványban
Advanced colorimetry Colour appearance models chromatic adaptation vonkries transformation CIE (Nayatani) proposal Bradford transformation Hunt model CIECAM97s model Colour management
Metamerism Different spectra, identical tristimulus values Metamerism indices: Illuminant Observer Radiance factor 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 Sample 1 Sample 2 0.1 0 400 450 500 550 600 650 700 Wavelength, nm
CIE Whiteness formulae Whiteness: W Y + 800(x n -x) + 1700(y n - y) Tint: T W 1000 (x n -x) + 650(y n - y)
Signal colours