Out of Curiosity and for learning i try to understand how the datacolor spyder 5 “works” with Argyllcms.
It seams to have 7(+1 on the front) light sensor with known spectral sensitivity curves.
This curves are stored inside devices EEPROM:
eeprom file
spyd2_readEEProm_imp: returning ICOM err 0x0
EEPROM:
0000: ff ff ff ff ff 0a 0f ff 35 30 30 35 38 35 34 35 …50058545
0010: 01 01 0a 00 00 2f 58 ff ff 3c 92 f7 85 3f 15 cd …/X…<…?..
0020: b8 be a2 f3 c4 be ca 27 54 3e 04 3c 76 bd 94 ee …'T>.<v…
0030: 95 3d 3b 90 bd ff ff ff ff ff ff ff 3f 80 00 00 .=;…?..
0040: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 …
0050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 …
0060: 00 00 00 00 3f 80 00 00 00 00 00 00 00 00 00 00 …?..
0070: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 …
0080: 00 00 00 00 00 00 00 00 00 00 00 00 3f 80 00 00 …?..
0090: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 …
00a0: 00 00 00 00 00 00 00 00 ff ff ff ff ff ff ff ff …
00b0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff …
00c0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff …
00d0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff …
00e0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff …
00f0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff …
0100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff …
0110: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff …
0120: ff ff ff ff ff ff ff ff ff ff ff ff 20 03 61 0a … .a.
0130: be 1c 5b 2e 8d 36 be 3c c8 43 a9 4b 6c 52 d0 55 …[…6.<.C.KlR.U
0140: 55 5a cf 5e 1c 64 f5 69 52 70 64 76 e9 7a 2b 7c UZ.^.d.iRpdv.z+|
0150: cd 79 23 73 de 69 fd 5f 66 55 b2 49 c2 3d 73 32 .y#s.i.fU.I.=s2
0160: f4 27 93 1e a7 16 3e 10 45 0b 92 07 07 05 45 03 .'…>.E…E.
0170: 20 02 5e 01 e6 00 9c 00 68 00 5c 00 56 00 00 00 .^…h..V…
0180: 97 01 9a 01 4c 01 ce 06 bf 20 32 36 3b 40 45 47 …L… 26;@EG
0190: 0a 4c cb 51 6c 56 7b 5a 55 5e e7 62 21 68 00 6d .L.QlV{ZU^.b!h.m
01a0: a7 6f 18 6f 02 6a a7 61 0a 58 81 4d 1a 42 e8 36 .o.o.j.a.X.M.B.6
01b0: a8 2c 53 23 1e 1b 32 14 93 0e 2d 0a de 06 93 04 .,S#…2…-…
01c0: fa 02 ef 01 3e 01 d1 00 8d 00 61 00 48 00 00 00 …>…a.H…
01d0: 00 02 d1 04 08 0a 91 0c 15 0c 3b 0c 2d 0e fd 12 …;.-…
01e0: 9d 1c 4a 2d 74 43 f2 54 55 5f 10 66 39 6c f5 71 …J-tC.TU.f9l.q
01f0: 6d 76 e9 77 cb 75 39 6f d5 65 b1 5b c3 50 b1 44 mv.w.u9o.e.[.P.D
0200: 88 38 67 2d 8e 23 0d 1b f5 13 37 0e cc 09 92 06 .8g-.#…7…
0210: 66 04 e7 02 ee 01 44 01 d8 00 94 00 67 00 50 00 f…D…g.P.
0220: 3f 00 00 00 00 00 00 00 00 00 75 00 00 00 69 00 ?..u…i.
0230: 00 00 a0 00 00 01 ca 02 5e 09 37 19 ab 30 3e 48 …^.7…0>H
0240: 7e 5a 58 66 d1 6b 0f 6c 57 67 b4 5f 1e 57 a7 4d ~ZXf.k.lWg._.W.M
0250: fc 42 0e 38 be 2d 2f 24 ac 1b 7f 14 b4 0e 34 0a .B.8.-/$…4.
0260: db 06 8d 04 f3 02 e9 01 38 01 ca 00 85 00 58 00 …8…X.
0270: 3d 00 00 00 00 00 00 00 d5 00 c3 00 b0 00 ac 00 =…
0280: c3 00 0b 01 68 01 e4 01 f0 02 16 05 45 09 62 11 …h…E.b.
0290: 2b 1f 24 31 4d 45 01 5a 28 6a e4 6f 68 6c 63 64 +.$1ME.Z(j.ohlcd
02a0: e0 59 7d 4d aa 40 8e 34 6f 29 9c 1f 64 17 ca 10 .Y}M.@.4o)…d…
02b0: ad 0b de 07 3d 05 69 03 37 02 6b 01 ec 00 9d 00 …=.i.7.k…
02c0: 69 00 4b 00 00 00 00 00 00 00 00 00 00 00 00 00 i.K…
02d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 …
02e0: 00 00 29 00 3d 00 77 00 2c 01 3f 03 20 08 33 11 …).=.w.,.?. .3.
02f0: 46 1e 69 2b c4 32 93 32 14 2d 28 25 f0 1c 9e 15 F.i+.2.2.-(%…
0300: 95 0f db 0a 51 07 de 04 29 03 0b 02 4d 01 d7 00 …Q…)…M…
0310: 8e 00 5e 00 41 00 28 00 00 00 00 00 00 00 00 00 …^.A.(…
0320: 00 00 00 00 00 00 00 00 00 00 00 00 45 00 53 00 …E.S.
0330: 66 00 7b 00 95 00 b0 00 c5 00 dc 00 01 01 05 01 f.{…
0340: f3 00 6b 01 d6 06 aa 19 38 2c f7 2e c9 28 d9 20 …k…8,…(.
0350: 05 19 b3 11 50 0c a7 08 e6 05 dd 03 83 02 9b 01 …P…
0360: 0a 01 af 00 73 00 51 00 00 00 ff ff ff ff ff ff …s.Q…
0370: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff …
0380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff …
0390: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff …
03a0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff …
03b0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff …
03c0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff …
03d0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff …
03e0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff …
03f0: ff ff ff ff ff ff ff ff ff ff ff ff 8d 8a 99 15 …
i got this from “spotread -D9”
First of all, does anyone have a similar device and can post their output and EEPROM file?
I’m curious if this is per-device individual calibration data or if all the data is the same.
This was my “sloppy” attempt to plot the data:
It’s made with Claude, so it could be wrong, but it looks plausible so far.
But the question of “how does it work” is still unanswered for me, and sadly I’m not a good programmer nor a mathematician.
Maybe someone here understands it well enough to explain it simply to me.
The “normal” CIE 1931 color space is already a 3-dimensional space derived from the eye’s three spectral sensitivity curves, and we usually map it to a 2-dimensional space.
So this must be a 7-dimensional color space?! That alone breaks my brain.
ArgyllCMS allows you to load a monitor spectral power distribution as well to get more accurate results.
I assume the monitor/illuminant SPD gets multiplied with every channel SPD?
Is there a way to capture/take a reading and then later try different monitor/illuminant SPDs to see the change?
The ultimate goal is to use this device as a universal USB light/color meter,
and possibly even make rough estimates about light “quality”.