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GretagMacbeth ColorChecker®
The GretagMacbeth ColorChecker® has been around since 1976 when it was called the Macbeth ColorChecker®. Originally proposed by C. S. McCamy, H. Marcus and J. G. Davidson in 1976 as a test for photography, television and printing, it is still being produced and used for a variety of color tests and color profiling.
Description
The ColorChecker® consists of 24 squares of paint applied to paper then mounted to a cardboard backing with a black frame around all the patches. The colors were chosen to represent various natural objects, colors that are problematic for color reproduction, additive and subtractive primaries, and a gray scale.
Originally offered in a 13 x 9 inch form only, the ColorChecker® is currently offered in an 11 x 8 inches size and a pocket sized Mini ColorChecker® at 3.25 x 2.25 inches.
Data
| Original Munsell Notation | CIE 1976 L*a*b*, D50, 2° | ||||
| Name | Hue | Value/Chroma | L* | a* | b* |
| Dark skin | 3.05 YR | 3.69/3.20 | 39.07 | 13.70 | 14.37 |
| Light skin | 2.2 YR | 6.47/4.10 | 66.36 | 18.08 | 18.56 |
| Blue sky | 4.3 PB | 4.95/5.55 | 50.66 | -4.84 | -21.44 |
| Foliage | 6.65 GY | 4.19/4.15 | 44.03 | -13.01 | 22.34 |
| Blue flower | 9.65 PB | 5.47/6.70 | 55.87 | 8.88 | -24.79 |
| Bluish green | 2.5 BG | 7/6 | 71.47 | -32.98 | 0.65 |
| Orange | 5 YR | 6/11 | 62.37 | 36.05 | 56.58 |
| Purplish blue | 7.5 PB | 4/10.7 | 40.77 | 9.18 | -43.58 |
| Moderate red | 2.5 R | 5/10 | 51.68 | 48.21 | 16.75 |
| Purple | 5 P | 3/7 | 31.27 | 20.00 | -20.83 |
| Yellow green | 5 GY | 7.08/9.1 | 72.74 | -22.60 | 57.15 |
| Orange yellow | 10 YR | 7/10.5 | 72.35 | 19.57 | 68.76 |
| Blue | 7.5 PB | 2.90/12.75 | 29.61 | 13.63 | -49.65 |
| Green | 0.1 G | 5.38/9.65 | 55.61 | -37.19 | 31.81 |
| Red | 5 R | 4/12 | 42.23 | 55.32 | 27.45 |
| Yellow | 5 Y | 8/11.1 | 82.65 | 4.44 | 80.52 |
| Magenta | 2.5 RP | 5/12 | 52.55 | 49.33 | -14.42 |
| Cyan | 5 B | 5/8 | 52.24 | -28.24 | -27.14 |
| White | N | 9.5/ | 96.37 | -0.30 | 3.26 |
| Neutral 8 | N | 8/ | 81.70 | -0.56 | 0.25 |
| Neutral 6.5 | N | 6.5/ | 66.49 | -0.33 | 0.03 |
| Neutral 5 | N | 5/ | 50.67 | -1.06 | -0.19 |
| Neutral 3.5 | N | 3.5/ | 36.23 | -0.48 | -0.26 |
| Black | N | 2/ | 20.68 | 0.17 | -0.55 |
The Munsell data is from the original McCamy et al publication. CIE 1976 L*a*b* coordinates were obtained by averaging spectral measurements from two October 2002 edition ColorCheckers®. The charts were measured with a GretagMacbeth Spectrolino® equipped with a D65 filter. The spectral data was acquired, averaged and analyzed with SpectraShop™.
Color Management Profiling
For color profiling purposes, it is imperative that a custom reference file be created for each individual chart. This is especially important for programs that perform spectral profiling because the ColorChecker® colorants have been reformulated several times since its original release and the spectra for many of the patches have changed significantly. It is to GretagMacbeth's credit that they have maintained the appearance of the patches during these reformulations but the profiling packages do not offer reference files for the different ColorChecker® editions. It is up to the user to make a custom reference file by measuring their individual ColorCheckers®.
Reference
C. S. McCamy, H. Marcus, J. G. Davidson, A Color-Rendition Chart, Journal of Applied Photographic Engineering, Volume 2, Number 3, Summer 1976, pages 95-99.
Updated 11.4.2007
Copyright ©2007 Robin D. Myers, all rights reserved.
