Colour Calibration

2023 January 02 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:

LAB is from Lab
First RGB is sRGB, sR s G sB
Second RGB is Adobe RGB aR aG a B

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:

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.