The ColorChecker, photography's most important 24 squares, turns 50 | Hacker News Reader

The ColorChecker, photography's most important 24 squares, turns 50

dpreview.com

123 pointssohkamyung28 comments

I've wanted a ColorChecker as a nice-to-have for a while, but real ones are kind of expensive (understandably so) for me.

As it turns out, paint samples that you can get at the hardware store for free are made with remarkably accurate colors. Although there are many like it, I found this nice video[1] about how to DIY a color checker. He lists the names of the colors in the description. But at least he confirms that even a near match works well!

However, I found that the paint companies change their colors slightly pretty frequently. But the Wikipedia article on ColorChecker[2] has a listing of the exact colors in the ColorChecker. So you can use a site like Match My Paint Color[3] to find the nearest paint color to put together a list of color names that you can then go scoop up at your local hardware store!

1. https://www.youtube.com/watch?v=pusFS7JmKQM 2. https://en.wikipedia.org/wiki/ColorChecker 3. https://www.matchmypaintcolor.com/

>the Wikipedia article on ColorChecker[2] has a listing of the exact colors in the ColorChecker

That's only exact under CIE Illuminant C lighting, which approximates overcast outdoor lighting. Most indoor lighting has a lower color temperature than this, and in the case of LED/fluorescent lighting, a more uneven spectrum. To accurately duplicate the colors of a ColorChecker under all lighting conditions, you need the full color spectrum of each panel. Wikipedia links to a web site with this data:

https://babelcolor.com/colorchecker.htm

> I've wanted a ColorChecker as a nice-to-have for a while, but real ones are kind of expensive (understandably so) for me.

Everyone has their own budget (esp. for hobbies), but if you're into photography, a USD 100-120 'accessory' does not seem "expensive":

* https://calibrite.com/us/product/colorchecker-classic/

* https://calibrite.com/us/product/colorchecker-passport-photo...

How much would a new (or new-to-you/used) camera body cost? Or a lens? Given that it would last probably over a decade, that's a pretty low annual amortization cost. Perhaps ask for it as a birthday or Christmas present?

Though it may depend on your subject matter: probably less of a need for it if you do landscape or street photography, as compared to portraits or products.

Some of the monitor calibration devices can get more pricey if you want to go down the colour calibration rabbit hole:

* https://www.datacolor.com/spyder/products/

Like Pantone books, color checkers don't last long before the colors fade, maybe a year or less. I remember being surprised at how much money we were spending on them.

I don't know anything about it, but I find this interesting, perhaps slightly surprising. It doesn't suprise me that it would fade, but, that being a presumably known problem, do the color checkers not have a good cover/case for storage? (something foil backed or similar to really block out the light)? Or do they even fade quickly just from being taken out briefly for use?

The colors may also fade/drift upon exposure to air and humidity, not just light.

Oh, interesting. That does make sense.

I worked in camera department on a low budget feature and one of my contributions was using a ColorChecker. The DP was concerned it would take too much time, and the director echoed those concerns. We compromised by only using the chart on the first take of each new setup. Nobody complained about how long it took to slate/chart once we got into production. I did get a message of appreciation from the director once they went to post. The editor/colorist sung the praise of having that data available.

The ColorChecker is one of those things that once you know its power, you'll never want to not use it again. Of course, you'll not use it for everything unless you're trying to impress. It's just one of those things that have fallen out of favor with digital. Things like light meters, chip charts, etc are just things younger people never working in film seem to not learn about any more

> The DP was concerned it would take too much time, and the director echoed those concerns. We compromised by only using the chart on the first take of each new setup.

How long does it take to hold up a rectangle? It's not like something like a Passport is very big or bulky:

* https://www.youtube.com/watch?v=noCxKKB5hCI

Your link is about the smaller "pocket" version. I would use that for the close up shots for inserts or whatever where the framing is too tight for the full size chart. The full size chart[0] is closer to the size of a slate. So after slating, I'd just move the chart from behind the slate to the front.

It was the first feature length for both the DP and director, and it was just one of the learning things for them from the experience. Maybe they thought it needed to be on screen for longer than necessary?? Either way, neither complain about using one again.

[0] https://www.datacolor.com/spyder/products/spyder-checkr-24/

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?

The Wikipedia article is far more informative, though I'm uncertain if read the full dpreview article due to ad-induced nausea.

https://en.wikipedia.org/wiki/ColorChecker

> "read the full dpreview article due to ad-induced nausea"

lol, made me chuckle.

Tip:

1. install "uBlock Origin", and configure it to "Medium Mode" [1]

2. Install "Obsidian Web Clipper" and use the "Reading View" button to read articles [2]

Trust me, you'll love it.

[1] https://github.com/gorhill/uBlock/wiki/Blocking-mode#medium-...

[2] https://addons.mozilla.org/en-US/firefox/addon/web-clipper-o...

https://en.wikipedia.org/wiki/Color_chart is even better if you want to just know about the subject.

The Viking Mars Lander had an early colour chart (three times over, for some reason) as shown in this NASA photo: https://www.msss.com/mars/pictures/viking_lander/22a158corr....

That lander had all sorts of fiddly protrusions on it, so the multiple charts could have been to avoid self-shadowing all of them. Or they were worried about chart stability after shipping it across interplanetary space. Or the test targets were for angles for multiple cameras?

> 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!

Not the exact same inks, for sure, but as a slight tangent—having grown up with RGB/YUV/CIE coordinates and Pantone swatches and process-color printing, but without painterly training, I’d long imagined the world of physical color reproduction to be largely continuous over the perceptible gamut.

In the spirit of the classic “Reality Has a Surprising Amount of Detail,” [0] I realized relatively late in life how finite and how discrete the set of colored substances—pigments, dyes, inks, reflective nanostructures—is. That, for example, ultramarine means ~the same thing today as it did in the lapis mines centuries ago, and so on. Frustrated, of course, by things like impurities and degradation at the hands of time and light and medium… but nevertheless finite sets of color-reflecting substances and applications at the bottom.

In my case, it was the Forbes Pigment Collection that got me started thinking about it:

https://harvardartmuseums.org/article/pigment-collection-col...

And the strange notion of “new” colors, like YInMn Blue [1], and formulations, like Klein Blue [2] (to dwell just on ultramarine-style blues!)

…I still don’t have a firm enough handle on color in all its glorious complexity to have a real point: you’re right of course that even within tightly-controlled production processes anchored in chemical reality, things drift and it’s worth paying somebody to measure if it’s important to be right—I just thought I’d offer the notion as a Sunday morning treat, in the hope that somebody else found the rabbit hole as delightful as I did :)

[0] https://johnsalvatier.org/blog/2017/reality-has-a-surprising...

[1] paper (PDF, open access): https://www.sciencedirect.com/science/article/pii/S259004982...

blurb: https://chemistry.oregonstate.edu/chemistry-news-events/yinm...

[2] https://www.centrepompidou.fr/en/pompidou-plus/magazine/arti...

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.

Pleasantly surprised to see dpreview still running, I thought they had shut down. It was a fantastic site back in the day. Not sure how it fares these days.

The paper where the target values originated:

https://home.cis.rit.edu/~cnspci/references/mccamy1976.pdf [1976, PDF]

It’s a charming read, with lines like

> The orange and Yellow patches visually matched some samples of oranges and lemons, both freshly picked, not dyed.

> Some blue flowers, most notably the morning glory of the variety "Heavenly Blue," are prized for their blue color, but frustrate the attempts of photographers to depict them.

…speaking as a longtime cultivator of morning glories—I’m gazing at a “Heavenly Blue” variety in bloom as I write [0]—they are absolutely correct; and I love that this fact informs the norms of the entire photographic industry!

And, of course, the bottom line:

> Having developed a well-characterized test object, we feel obligated to point out that color-reproduction systems hardly ever reproduce all colors exactly. The practical limitations of such processes make perfect color reproduction virtually impossible.

[0] https://www.gardenia.net/plant/ipomoea-tricolor-heavenly-blu... — and if those charm you, may i recommend the ‘Keiryu’ / ‘Mountain Stream’ variety, which, needless to say, is far more impressive than the photos suggest: https://organicplantit.com/product/keiryu-mountain-stream-mo...

The DP Review page is worthless, but it links to the museum here which is a nicely designed page, but written by LLM, so be warned:

https://calibrite.com/us/50-years/

Nostalgia! 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.

In other news, dpreview is still around and I didn’t know it.

I used to visit it daily.

Looks to have been acquired by Gear Patrol at the very last moment before shutdown

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