Using the natural reflectance spectra that a DPR PS&T member supplied me, and illuminating all the samples with D50 light, I looked at the errors with an optimized compromise matrix generated by training on the CC24, the CC SG, the CC Passport, and the natural spectra themselves.
As expected, training on the natural spectra was the most accurate, but the others weren’t that far behind. I tested with many simulated cameras.
Also as expected, the differences were the smallest in the cameras that were the most accurate.
In case anyone’s interested, here is the natural reflectance spectra set. There are a few points that look like errors, but it mostly looks pretty realistic to me.
What the camera sees is the above multiplied wavelength by wavelength by the spectrum of D50 light.
The natural spectra set I used was mostly botanical in origin. Here are the names of the samples:
- greenleaf(leskenlehti)
- yellowflower(keltano)
- greenleaf(keltano)
- yellowflower(kannusruoho)
- yellowflower(kannusruoho)
- graydryflower(pelto-ohake)
- violetflower(pelto-ohake)
- greenleaf(pelto-ohake)
- violetflower(alsikeapila)
- greenleaf(alsikeapila)
- browndryleaf(hevonhierakka)
- browndryflower(hevonhierakka)
- greenleaf(koristeherukka)
- redberry(koristeherukka)
- redleaf(koristeherukka)
- blueflower(hiidenvirna)
- yellowflower(voikukka)
- greenrod(voikukka)
- greenleaf(voikukka)
- yellowflower(niittyleinikki)
- whitepetal(ojakaersaemoe)
- whiteflower(petunia)
- greenrod(petunia)
- redflower(petunia)
- yellowflower(pietaryrtti)
- whitepetal(peltosaunio)
- yellowflower(peltosaunio)
- greenleaf(poimulehti)
- browndryleaf(poimulehti)
- violetflower(harakankello)
- whitepetal(siankaersaemoe)
- violetflower(niittyhumala)
- greenleaf(niittyhumala)
- greenleaf(paju)
- greenleaf(hopeapaju)
- violetflower(maitohorsma)
- greenleaf(maitohorsma)
- greenleaf(lehmus)
- greenflower(lehmus=linden)
- yellowpetal(lehmus)
- greenleaf(pihlaja)
- orangeberry(pihlaja)
- greenleaf(kehaekukka)
- orangeflower(kehaekukka)
- brownrod(uudenguineanliisa)
- greenleaf(uudenguineanliisa)
- redflower(uudenguineanliisa)
- violetflower(orvokki)
- greenleaf(orvokki)
- violetflower(akilleija)
- greenleaf(akilleija)
- yellowflower(suikeroalpi)
- greenleaf(suikeroalpi)
- violetflower(kissankello)
- browndryflower(kissankello)
- light
- redflower(lupiini)
- browndryflower(lupiini)
- violetflower(lupiini)
- violetflower(lupiini)
- blueflower(kurkkuyrtti)
- greenleaf(kurkkuyrtti)
- redflower(hevosminttu)
- browndryleaf(hevosminttu)
- greenrod(hevosminttu)
- greenleaf(nukkajaekkaerae)
- greenrod(nukkajaekkaerae)
- whiteflower(nukkajaekkaerae)
- greenleaf(maksaruoho)
- greenrod(maksaruoho)
- white”rod,”innerpart(maksaruoho)
- blueflower(ukonhattu)
- greenleaf(ukonhattu)
- yelllowflower(pietaryrtti)
- blueflower(sinisievikki)
- whitepetal(sinisievikki)
- yellowflower(pensashanhikki)
- yellowsepal(pensashanhikki)
- blueflower(iisoppi)
- redflower(kurttulehtiruusu)
- greenleaf(pajuangervo)
- redflower(pajuangervo)
- yellowflower(dalia)
- redflower(dalia)
- redflower(jaloangervo)
- redflower(neilikka)
- redpetal(pelargonia)
- whitepetal(pelargonia)
- whitepetal(paeivaenkakkara)
- yellowflower(paeivaenkakkara)
- greenleaf(paeivaenkakkara)
- violetflower(punataehkae)
- redflower(talvio)
- greenleaf(talvio)
- greenleaf(talvio)
- blueflower(lobeliadortmanna)
- blueflower(malvikki)
- greenleaf(malvikki)
- redflower(malvikki)
- redflower(malvikki)
- “red,”paleflower(ruusu)
- “red,”darkflower(ruusu)
- greensepal(ruusu)
- whiteflower(ruusu)
- redflower(unikko)
- greenlichen(peltigeracaniinanahkajaekaelae)
- brownlichen(peltigeracaniinanahkajaekaelae)
- whitelichen(peltigeracaniina)
- brownleaf(haapa)
- redleaf(haapa)
- redleaf(haapa)
- browndryleaf(haapa)
- yellowleaf(haapa)
- greenleaf(haapa)
- yellowleaf(takiainen)
- brownleaf(takiainen)
- redleaf(maitohorsma)
- blackdryleaf(maitohorsma)
- greenleaf(piharatamo)
- redleaf(pihlaja)
- yellowleaf(pihlaja)
- orangeberry(pihlaja)
- greenleaf(pihlaja)
- greenleaf(koivu)
- greenleaf(koivu)
- yellowleaf(koivu)
- greenleaf”(koristepensas,”tuntematon)
- yellowleaf”(koristepensas,”tuntematon)
- yellowleaf”(koristepensas,”tuntematon)
- orangeleaf”(koristepensas,”tuntematon)
- yellowleaf”(koristepensas,”tuntematon)
- pink(siankaersaemoe)
- violetflower(petunia)
- whiteflower(petunia)
- whiteflower(orvokki)
- blueflower(orvokki)
- violetflower(orvokki)
- yellowflower(orvokki)
- “brown,”deadflower(orvokki)
- whiteflower(orvokki)
- greenleaf(orvokki)
- redberry(puolukka)
- yellowpetal(auringonkukka)
- greensepal(auringonkukka)
- greenberry(kataja)
- whiteflower(silmaeruoho)
- yellowleaf(maitohorsma)
- browndryleaf(maitohorsma)
- light
- browndryrod(koiranputki)
- yellowflower(linnunkaali)
- greenleaf(linnunkaali)
- greenleaf(poimulehti)
- greenleaf(poimulehti)
- yellowleaf(poimulehti)
- browndryleaf(poimulehti)
- orangeleaf”(koristepensas,”tuntematon)
- greenleaf(kanukka)
- redleaf(kanukka)
- reddish
- brownleaf(kanukka)
- greenleaf(keltano)
- greenleaf(korvakeltano)
- yellowleaf(keltano)
- greenleaf(koiranheisi)
- redberry(koiranheisi)
- greenmoss(nuotiosammal)
- brownmoss(nuotiosammal)
- blacksoilgraylichen(nahkajaekaelae)
- yellowleaf(tuomi)
- blackberry(tuomi)
- greenfruit(maenty)
- brownfruit(maenty)
- greenneadle(maenty)
- yellowleaf(koivu)
- yellowleaf(koivu)
- greenleaf(koivu)
- “brown,”dryleaf(koivu)
- “brown,”dryleaf(koivu)
- yellowleaf(lehmus)
- orangeleaf(lehmus)
- “brown,”dryleaf(lehmus)
- yellowleaf(lehmus)
- orangeleaf(mustikka)
- greenleaf(mustikka)
- redleaf(mustikka)
- yellowleaf(pihlaja)
- orangeleaf(pihlaja)
- redleaf(pihlaja)
- redleaf(pihlaja)
- brownleaf(pihlaja)
- “black,”dryleaf(pihlaja)
- redberry(pihlaja)
- “brown,”oldberry(pihlaja)
- orangeleaf(terttuselja)
- redberry(terttuselja)
- greenleaf(paju)
- yellowleaf(paju)
- yellowleaf(paju)
- brownleaf(paju)
- whiteleaf(vadelma)
- brownleaf(vadelma)
- “brown,”oldleaf(voikukka)
- redleaf(voikukka)
- “gray,”dryleaf(kielo)
- greenleaf(koristeviinimarjapensas)
- orangeleaf(koristeviinimarjapensas)
- redleaf(koristeviinimarjapensas)
- orangeleaf”(koristepensas,”tuntematon)
- yellowleaf”(koristepensas,”tuntematon)
- yellowleaf”(koristepensas,”tuntematon)
- yellowleaf(vaahtera)
- yellowleaf(vaahtera)
- yellowleaf(vaahtera)
- orangeleaf(vaahtera)
- redleaf(vaahtera)
- brownleaf(vaahtera)
- brownleaf(vaahtera)
- brownleaf(vaahtera)
- brownleaf(vaahtera)
- redleaf(pihlaja)
[…] on a number of databases. The ColorCheckers did unexpectedly well. See for instance his blog here. 4. The Excel spreadsheet with BabelColor.com average measured reflectances of 30 ColorChecker 24 […]