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.
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 MiniáColorChecker® at 3.25 x 2.25 inches.
|Original Munsell Notation||CIE 1976 L*a*b*, D50, 2░|
|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|
|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|
|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|
|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|
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™.
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 (now X-Rite'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®.
The spectral data for many different editions of the ColorChecker® may be downloaded from the Spectral Library. Using these files with the demo version of SpectraShop™ will allow you to compare the spectra for the different editions and get colorimetric values for a large variety of viewing conditions.
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.
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