D & H Color Rule Review / HowTo

The D & H Color Rule, made by the Davidson & Hemmendinger Company in 1967. A slide-rule type gadget for measuring color metamerism.
This is episode 70 of my video series about old calculating devices.
End song inspired by "Hotter than a Molotov" by The Coup.
Chris Staecker webarea: faculty.fairfi...
#metamerism

[@ChrisStaecker]

I decided not to mention the original owner's name, since I didn't get permission from anybody (AIM or the estate) to make this video. For anyone who wants to guess whose it was, I will reply "Pretty good guess, but my little lips are sealed!"

[@jamesonhardy2126]

No permission? You're the bad boy of calculator videos.

[@ChrisStaecker]

@@jamesonhardy2126 It's a crowded field! Gotta stand out somehow

[@bobmackay1856]

No way! Such a con!

[@rizzwan-42069]

Must be uh ronald from that workshop

[@Jimorian]

What a neat little device. In videography we do "white balancing" all the time, but color balancing is usually beyond what we have time to do. What is important, though, is if you're using multiple cameras, to be using the same brand and model if at all possible because of that device difference.

[@LarsDonner]

You know these guys must've been serious, with the shape of the CIE 1931 color space as their logo.

[@ChrisStaecker]

Yes! I should've noticed that

[@pierrer.m1802]

What about the other graph on the right? There's two curves, so I guess each one is related to one of the sliding parts?...

[@ChrisStaecker]

@@pierrer.m1802 I don't recognize it, but I'm interested if anyone does-

[@FiveTrackTape]

@@ChrisStaecker Likely a Spectral Reflectance Graph. Reflectance on the vertical scale, wavelength on the horizontal. Shown in the KZbin video "How to identify and evaluate metamerism".

[@MattMcIrvin]

As a laser printer guy going way back, that immediately jumped out at me.

[@collintmay]

Fascinating! I work in the print industry and was just explaining to a customer how colors can shift appearances in different light environment. I wasn't aware there was a word for that!

[@mixer0014]

Despite the simple working principle, creating a callibrated scale for this device must have been a hard task. Even printing the colorful bars without some other color-measuring gadget could be a problem. Has chicken-and-egg paradox vibes.

[@ChrisStaecker]

Yes- at first I decided to make my own printable version, but immediately decided that I'm not really sure if I could get the same effects using color laser printer ink- I assume the choice of pigment ingredients matters.

[@wahyutriwibowo1803]

@@ChrisStaecker You could compare it with standard color palettes like PANTONE if you want to reproduce it. Many design office, print shop, art studio use one.

[@ChrisStaecker]

But the metameric effects are also influenced by the pigments themselves, right? The glossiness, etc- I won’t be able to control that stuff with a normal office printer. But maybe that’s not important? I don’t know.

[@AndyLundell]

@@ChrisStaecker Sounds like you're in the market for a "Colorant Mixture Computer".

[@ChrisStaecker]

Yeah- you got one lying around?

[@farpointgamingdirect]

As a retired master pressman and ink technician, this device is facinating; Color samples were visually checked in a "light box" then verified with a spectrodensitometer. I actually made a spreadsheet to calculate color corrections in flexographic inks to help me in my work. My former boss tried to claim it as his own creation, so I password protected it and hid my name all through the sheet. I eventually took it with me when I left. I bet theyre still having problems matching Coca-Cola red

[@phookadude]

Love how their logo is the color space.

[@lizzyfrizzy4969]

When you hang something on the wall, and its level, but it doesnt look straight, you can do 3 things 1 use the datum from the ceiling line 2 use the datum from the floor line 3 "split the difference" carpenters trick, measure both and divide them.

[@retrogiftsuk4812]

Or "4 try a different wall'

[@pubcollize]

It still might look different from different points in the room

[@chriswalford4161]

…or use a tapered frame.

[@biquinary]

such a great series, always so interesting

[@AlRoderick]

The manufacturers of window tint material would have done the exact same thing you did, checked the light quality on both sides of the window to make sure it didn't actually change the colors. So really you're just checking their work.

[@johnsrabe]

Waaaaait a minute the guy who co-developed a color thingy is named Hugh?!?!?!? It could only be better if his name was Hugh Gage!

[@AndyLundell]

I don't know if it's true or not, but there's a story about the filming of the original Star Trek where metamerism screwed them up. Supposedly captain Kirk's regular uniform and his formal dress uniform were supposed to be the same color. They were different materials, but the costume designer matched the colors so they looked the same. But then some combination of the studio lights and the film they were using made the two colors look completely different. On screen, His regular uniform is a gold/yellow, but his dress uniform is a lime green. Too bad Gene Roddenberry didn't have a D&H Color Rule.

[@samsanchez748]

RIP John Conway

[@TheBookDoctor]

Super interesting. I'd never heard of color metamerism. Learn something new every day!

[@pierrer.m1802]

Now all we need is a GraphAnalogue-like Color Helm machine that takes metamerism into account, with one scale/helm for every letter+number combination...

[@Mural]

A lovely video as always. I don't envy anyone who has to sort through a lifetime of someone's notes

[@ChrisStaecker]

This person is important enough that somebody will be happy to do it someday.

[@johnsrabe]

1. Does it come with other color strips? 2. Re your parting shot: Nope, but you knew that because the parallels with metamerism are exact. That a picture looks level is far more important than whether it is in fact level.

[@ChrisStaecker]

1- I don't think so. The instructions don't mention any other strips, and the descriptions of the Color Rule in the papers I mentioned don't either.

[@bertino6]

this was really interesting and well done - thanks!

[@BravoCharleses]

This speaks to why people in printing and other manufacturing disciplines will pay ~10k dollars for a Pantone color chip set which is, at its core, just a bunch of colored pieces of plastic. Our eyeballs and cameras are weird!

[@incamath4440]

Nice 👍🏽

[@yannisconstantinides7767]

I'm getting flashbacks to learning to classify soil by color.

[@ryanpitasky487]

Conway?

[@ChrisStaecker]

Pretty good guess, but my little lips are sealed!

[@baileykeller288]

I have a suggestion for a math prop. It's in the drawtectives show on the drawfee youtube channel season 1 episode 6. It forms for a while but the completed drawing is at about 48:40 in. It is a show about drawing so it's not a real prop, but I saw it and thought of your channel and I thought it would be funny if you had it in your series.

[@johnsrabe]

5:27 as a married man myself, I’m pretty sure you can stop that sentence at “brief lecture.”

[@pypes84]

Everyone's clearly too polite to point out that you're a foot taller than everyone else in that photo.

[@programaths]

Just explained to a friend why it's better to buy an expensive white lamp and put gels in front of it instead of buying a cheaper LCD lamps which can produce all the colors by itself 🤣He would have been puzzled by this ^^

[@ptmusicalboxes]

John Conway had the coolest thing.

[@getjaketospace]

Is this a helm??

[@circle9nerd]

When you're +2 standard deviations in height also, extra high five!

[@stephenfreeborn]

I composed a comment in my head about crimson red vs scarlet red and how I can’t tell them apart but my wife can. And obviously only a man would need this device because women can just tell. Then you said pretty much the same thing at the end of the video. Now I don’t know what to say.

[@JamesParker737]

Found one of these in my grandads loft while emptying it, would anyone have any pointers as to who could be interested in purchasing an item like this?

[@ChrisStaecker]

Nice! I’d suggest to put it on eBay. The thing is small and light enough that you can easily ship it. Decide how much you want for it, list it as a “buy it now”, and be prepared to wait a long time. There’s very few people who are going to seek this out, and an auction might end with a super-low price just because the people interested in this thing won’t know it’s on auction that week. Good luck!

[@jamesforrest9837]

obligatory algorithm boosting comment, what an amazing device! observer/device metamerism! that's a new brain wrinkle. i feel betrayed learning that my squishy eyeballs lied to me. i get why people were so heated about the dress.

[@clayupton7439]

wonder if the colors have faded over time..

[@ChrisStaecker]

Yes- I didn't mention it, but you can see a hard line at 1:13 which shouldn't be there. I assume it was stored for decades on a shelf with the two sliders in the same position, which caused the fading.

[@getjaketospace]

Is the owner Albert Einstein?

[@ChrisStaecker]

Pretty good guess, but my little lips are sealed!

[@not_just_burnt]

as someone with tritanomaly i "hate" this video. cool concept, most colors looked the same...

[@Gremriel]

Dear Lord, not that dress again.

[@nahumgardner]

Yanny or Laurel?