Colour Calibration

  4 min 19 s  

Standards

I used to have a Greta Mcbeth colour calibration both small and large but lost the large one and only have the small one left. Just recently purchased the Datacolor SpyderCheckr| 24 but probably should have bought the| 48 patch version in a hard shell. I have just discovered that| 24 patch is the right side of the| 48 patch. So can use the calibration data from that for checking the DataColour Print.

Colour matching quote:

The color patches on the right half of the SpyderCHECKR, and those on the
SpyderCHECKR24 represent the standard| 24  colors used in a variety of color
products. These patches are near or within the sRGB color gamut to avoid
gamut clipping...

Datacolor Checkr calibration values

Datacolor used to publish the LAB values with a slightly poor pdf as of 2017:

This has been captured by Christoph Bartneck and converted into a table. I have corrected and reproduced the table here and added the annotation for the| 24 patch version:

Number Patch Name L* a* b* sR sG sB aR aG aB
1 1A Low Sat. Red 61.35 34.81 18.38 210 121 117 189 121 117
2 2A Low Sat. Yellow 75.5 5.84 50.42 216 179 90 205 178 96
3 3A Low Sat. Green 66.82 -25.1 23.47 127 175 120 141 174 122
4 4A Low Sat. Cyan 60.53 -22.6 -20.4 66 157 179 103 156 177
5 5A Low Sat. Blue 59.66 -2.03 -28.46 116 147 194 125 146 191
6 6A Low Sat. Magenta 59.15 30.83 -5.72 190 121 154 172 120 151
7 1B 10% Red Tint 82.68 5.03 3.02 218 203 201 213 202 200
8 2B 10% Green Tint 82.25 -2.42 3.78 203 205 196 202 204 195
9 3B 10% Blue Unit 82.29 2.2 -2.04 206 203 208 204 201 206
10 4B 90% Red Tone 24.89 4.43 0.78 66 57 58 66 60 60
11 5B 90% Green Tone 25.16 -3.88 2.13 54 61 56 59 63 59
12 6B 90% Blue Tone 26.13 2.61 -5.03 63 60 69 65 63 71
13 1C Lightest Skin 85.42 9.41 14.49 237 206 186 225 202 183
14 2C Lighter Skin 74.28 9.05 27.21 211 175 133 200 174 134
15 3C Moderate Skin 64.57 12.39 37.24 193 149 91 180 148 95
16 4C Medium Skin 44.49 17.23 26.24 139 93 61 127 93 65
17 5C Deep Skin 25.29 7.95 8.87 74 55 46 71 58 50
18 6C 95% Gray 22.67 2.11 -1.1 57 54 56 59 57 59
19 1D 5% Gray 92.72 1.89 2.76 241 233 229 238 233 229
20 2D 10% gray 88.85 1.59 2.27 229 222 220 226 221 219
21 3D 30% Gray 73.42 0.99 1.89 182 178 176 180 177 174
22 4D 50% Gray 57.15 0.57 1.19 139 136 135 137 135 134
23 5D 70% Gray 41.57 0.24 1.45 100 99 97 99 99 98
24 6D 90% Gray 25.65 1.24 0.05 63 61 62 65 63 64
25 1E Card White 96.04 2.16 2.6 249 242 238 247 242 237
26 2E 20% Gray 80.44 1.17 2.05 202 198 195 199 196 193
27 3E 40% Gray 65.52 0.69 1.86 161 157 154 158 156 153
28 4E 60% Gray 49.62 0.58 1.56 122 118 116 120 118 115
29 5E 80% Gray 33.55 0.35 1.4 80 80 78 81 81 79
30 6E Card Black 16.91 1.43 -0.81 43 41 43 46 46 47
31 1F Primary Cyan 47.12 -32.5 -28.75 0 127 159 39 126 157
32 2F Primary Magenta 50.49 53.45 -13.55 192 75 145 167 76 141
33 3F Primary Yellow 83.61 3.36 87.02 245 205 0 234 204 37
34 4F Primary Red 41.05 60.75 31.17 186 26 51 159 32 53
35 5F Primary Green 54.14 -40.8 34.75 57 146 64 94 145 71
36 6F Primary Blue 24.75 13.78 -49.48 25 55 135 41 58 132
37 1G Primary Orange 60.94 38.21 61.31 222 118 32 196 117 44
38 2G Blueprint 37.8 7.3 -43.04 58 88 159 70 89 156
39 3G Pink 49.81 48.5 15.76 195 79 95 170 80 94
40 4G Violet 28.88 19.36 -24.48 83 58 106 78 61 104
41 5G Apple Green 72.45 -23.6 60.47 157 188 54 165 186 69
42 6G Sunflower 71.65 23.74 72.28 236 158 25 218 157 46
43 1H Aqua 70.19 -31.9 1.98 98 187 166 130 186 166
44 2H Lavender 54.38 8.84 -25.71 126 125 174 125 124 171
45 3H Evergreen 42.03 -15.8 22.93 82 106 60 90 106 65
46 4H Steel Blue 48.82 -5.11 -23.08 87 120 155 98 119 152
47 5H Classic Light Skin 65.1 18.14 18.68 197 145 125 183 144 125
48 6H Classic Dark Skin 36.13 14.15 15.78 112 76 60 103 77 63

Corrections

At the bottom of Barnecks table there are some comments about errors. I have assumed the LAB numbers are correct. I then used the original sRGB numbers to construct a plot:

{{ partial “svg” “datacolor24_a” }}

The Blueprint is clearly off when compared to my physical SpyderChekr24 sample. Stuart commented on Barnecks page square 2G has a typo by the way, it should be RGB 58/88/159

I recalculated all the sRGB values using python-colormath from the LAB values. Almost every value is off a little eg by 2, some by 3. The colour Blueprint 2G is clearly very different. My calculation has it as 58, 88, 159 and clearly wrong in the orginal Datacolor pdf. So this has been corrected to it.

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