The ColorChecker, photography's most important 24 squares, turns 50
dpreview.comNostalgia! I don't remember them coming out, but I was involved in setting up Calibrite. I was more involved in the monitor calibrators (my team developed the new software) and the infrastructure.
I didn't learn much from reading this article. Questions linger in my mind, for example: What are the CIE XYZ coordinates of each colored square? What is the spectral distribution of each square? How were the colors chosen?
> What are the CIE XYZ coordinates of each colored square?
In the most expensive versions, they measure each individual patch, in case printing imperfections make the colours slightly different. And of course because you can’t get the exact same inks when a product is 50 years old!
> How were the colors chosen?
Skin and foliage; primary colours; greyscale; and miscellaneous.
They also make a 140 colour patch version - the “ColorChecker Digital SG” - that provides more coverage; 14 different skin tones instead of 2 for example!
The Wikipedia article is far more informative, though I'm uncertain if read the full dpreview article due to ad-induced nausea.
You sound like you actually want to just generate them yourself using ArgyllCMS `targen` and `printtarg`.
I don't know about him but yes yes I do and you should want to, too! :^)
These aren't appropriate questions for the birthday party
These are great, even for manually-adjusted color workflows.
Fun fact, though: You have to replace them every couple of years (or sooner) because no pigment/dye is stable, especially if exposed to bright light.
Having a test shot with one of these in it saves you untold amounts of pain later.
Many of them, especially the smaller hard-case versions, have a space to write date of first-use.