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Spectrophotometer Analysis of Crayons

Unknown Lamer posted more than 2 years ago | from the ooo-pretty-colors dept.

Graphics 40

Volhav writes "Like many as a child, the photographer Mark Meyer wondered what the difference between Yellow-Green and Green-Yellow was in that Crayola box of crayons. Using a monitor calibration tool and the Argyll 3rd party software he evaluated a box of 24 Crayola crayons, and plotted them out with sRGB values. He even included a nice printable poster size version of the chart in his blog post. For the geek or curious this was a pretty interesting plot."

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40 comments

24 (0)

Anonymous Coward | more than 2 years ago | (#37460386)

24, not 64.

Re:24 (1)

Unknown Lamer (78415) | more than 2 years ago | (#37460442)

Thanks for catching the typo!

Re:24 (0)

Anonymous Coward | more than 2 years ago | (#37460510)

Oh, yes, a typo; obviously his finger slipped from the 2 to the 6. He must be using Dvorak.

Re:24 (0)

Anonymous Coward | more than 2 years ago | (#37463702)

Oh, yes, a typo; obviously his finger slipped from the 2 to the 6. He must be using Dvorak.

Or maybe the author is more familiar with the 24 count box of crayons.

Re:24 (1)

causality (777677) | more than 2 years ago | (#37461648)

Thanks for catching the typo!

So that's twice now you missed the "a box of 24 color box of" error?

Well, you're definitely a Slashdot editor.

Re:24 (1)

Unknown Lamer (78415) | more than 2 years ago | (#37462704)

Well then, I feel dumb. FWIW everyone else missed the typo too... if you tag a story typo it makes a jabber bot yell at me so I look harder at the text to find things like that.

Re:24 (1)

causality (777677) | more than 2 years ago | (#37480802)

Well then, I feel dumb. FWIW everyone else missed the typo too... if you tag a story typo it makes a jabber bot yell at me so I look harder at the text to find things like that.

Well damn. I was so used to Rob Malda's thick skin :-). If he ever felt dumb, he never told anyone so far as I know. No offense was really intended, just that Slashdot could really use a good copy editor sometimes. It would add that professional touch. I could do this. Typos like that practically leap out at me. I think the brains of most people unconsciously auto-correct things like that "box of" error and they don't easily notice. Mine does that too and the intent of the sentence is quite clear, only I'm aware that such an "auto-correction" took place, if that makes sense.

As far as tags go, that feature is broken for me. When tags first came out, they seemed to work for me. Since then, I have never once applied a tag to a story, refreshed the main page, and then see my tag in place. It appears to add the tag but refreshing the page makes it go *poof*. After a while I gave up. I'm guessing this is something other than a technical problem. I must have pissed in someone's cornflakes at some point (that wouldn't surprise me). I'm not really complaining because this is a free account, though it would be nice to know why.

For the geeks... (1)

ak_hepcat (468765) | more than 2 years ago | (#37460436)

He's also on twitter: @markmeyerphoto

Just in case you want to say hi.

(Always pimpin' my fellow Alaskans)

Re:For the geeks... (1)

Anonymous Coward | more than 2 years ago | (#37460894)

Are you the one who got Palin off the streets and into politics?

Real spectrophotometers (2)

vlm (69642) | more than 2 years ago | (#37460444)

Note that chemists have real recording spectrophotometers, not just monitor calibration gadgets. I spent way too long in my youth, if I recall correctly, classifying iron ore samples using one. Its a fairly elegant technique because accurate ultra wide range light sensors have been old stuff for decades. It seems like I took an entire 200 level quantitative chemical analysis chemistry class where all we did was F around with a spectrophotometer in different ways.

If I recall correctly, the infrared ones were the cats meow before NMR got "cheap" for classifying organic compounds.

Re:Real spectrophotometers (1)

Anonymous Coward | more than 2 years ago | (#37460546)

TFA says it's an i1Pro which is a legitimate spectrophotometer—significantly more than a monitor calibration gadget, but less than an industrial, lab grade spectro.

Re:Real spectrophotometers (0)

Anonymous Coward | more than 2 years ago | (#37460644)

Note that chemists have real recording spectrophotometers, not just monitor calibration gadgets.

Oh, be quiet and just enjoy nerding out for once in your life already.

Re:Real spectrophotometers (4, Funny)

punkmanandy (592682) | more than 2 years ago | (#37460836)

Note that chemists have real recording spectrophotometers, not just monitor calibration gadgets.

Oh, be quiet and just enjoy nerding out for once in your life already.

Some of us nerd out by pointing out our superiority, thank you very much!

Re:Real spectrophotometers (1)

vlm (69642) | more than 2 years ago | (#37461042)

Note that chemists have real recording spectrophotometers, not just monitor calibration gadgets.

Oh, be quiet and just enjoy nerding out for once in your life already.

Some of us nerd out by pointing out our superiority, thank you very much!

The nerding out bit is he could get dramatically better results using an even more ridiculously expensive tool, if he wanted to.

The standard /. car analogy is you can measure the even-ness of the gap between the door and body using a kids 75 cent wooden ruler to maybe as much as 2 sig figs, but a machinist could loan you a $250 digital dial caliper to get at around 3 sig figs, maybe 4.

I'm surprised no chemist out there has run this exact experiment... I know I'd be tempted if I was still in that field and had access to the proper gear...

Re:Many ARE real spectrophotometers (1)

thegarbz (1787294) | more than 2 years ago | (#37465922)

Only the bottom end of the calibration gadgets for monitors use characterised colourimeters. Many of the medium and higher end monitor calibration gadgets are proper spectrophotometers. Typically many of the devices where one device is capable of doing the entire colour workflow from scanner to monitor to printer and compare them to pantone charts are the real deal. The i1 PhotoPro is also roughly 10x the cost of your run of the mill "monitor calibration gadgets" like the i1 Display.

In this case his results even include a lovely spectrum as a result. Sure they don't cost $10k, they don't have a wide compliance for lux, they probably aren't 100% accurate and don't read outside the visible band, but that doesn't not make them real spectrophotometers.

Two questions (3, Funny)

Anonymous Coward | more than 2 years ago | (#37460638)

Has anyone done a similar plot evaluating the taste of the crayons?

And who pinned these mittens to my jacket?

Re:Two questions (1)

wsxyz (543068) | more than 2 years ago | (#37460700)

Despite your (and my) expectations, red crayons do not have a cherry flavor.
On the other hand, black crayons taste just like that black stuff I dig out from under my toenails every now and then.

Re:Two questions (1)

That Guy From Mrktng (2274712) | more than 2 years ago | (#37461302)

oh shit Richard Stallman is onto graphic design! Quick! alert Apple fanboys!

You should not patent rounded corner rectangles Apple, here look my toe nails, they have rounded corners since the beginning of UNIX time, are your iPads edible? because I know my toenails are. Stop thwarting the freedom of the rounded rectangles with your sub-par implementations.

Re:Two questions (1)

plover (150551) | more than 2 years ago | (#37461030)

That reminds me of one of my very favorite old Peanuts cartoons:
Lucy brings Linus a steaming mug, and says "I brought you a mug of hot cocoa."
Linus tastes it and says "It tastes like hot water with a brown crayon dipped in it."
Lucy tastes it and agrees, saying "You're right. I'll go add another crayon."

Re:Two questions (1)

PPH (736903) | more than 2 years ago | (#37462460)

Is your underwear marked "Anonymous Coward"?

Re:Two questions (1)

Anonymous Coward | more than 2 years ago | (#37463604)

It is now. Thanks for the suggestion.

Re:Two questions (1)

catmistake (814204) | more than 2 years ago | (#37463096)

I think the better question is, has anyone designed and implemented a full-color plotter that uses a pack of crayons as the replacement plotting filiment? Or has anyone designed a full-color display that somehow uses a pack of (maybe mentled) crayons? Then the poster might actually be useful.

Re:Two questions (1)

ChrisMaple (607946) | more than 2 years ago | (#37468766)

Not a plotter, but Tektronix did manufacture and sell a line of printers that melted a solid and spat it onto paper. Essentially, these "Phaser" printers used crayons. Xerox bought the printer line from Tektronix.

Why didn't I think of this!? (1)

iguana (8083) | more than 2 years ago | (#37461220)

I "work" with color science. We have an X-Rite spectrophotometer just sitting around. Takes an artist's thinking, I suppose.

I ran into a paper a while back where the author captured spectrum of 100s of "natural" objects. Rocks, leaves, skin, etc etc. Made for an interesting chromaticity diagram.

Re:Why didn't I think of this!? (1)

Pete Venkman (1659965) | more than 2 years ago | (#37463726)

I work in color chemistry too. I'd like to get excited about this article but it just reminds me of work and I start wondering about what the variation is in the individual colors between different boxes, or what the difference is between these same colors in the markers from the same manufacturer.

Re:Why didn't I think of this!? (0)

Anonymous Coward | more than 2 years ago | (#37472168)

I ran into a paper a while back where the author captured spectrum of 100s of "natural" objects. Rocks, leaves, skin, etc etc. Made for an interesting chromaticity diagram.

Link please...

Obligatory... (1)

srussia (884021) | more than 2 years ago | (#37461434)

"But there's way too much information to decode the Crayola. You get used to it. I...I don't even see the spectral signature. All I see is blonde, brunette, red-head..."

Who cares about sRGB? (0)

Anonymous Coward | more than 2 years ago | (#37461642)

Disclaimer -- I'm a flashaholic (see candlepowerforums.com for a sample of the geeks who adopt that label), your interest may vary...

The spectra are where it's at.

See, LEDs, CFLs, MH, and basically every other light source that isn't a glowing wire all suffer from the same deficiency -- their spectral distribution is "wrong", causing them to light up some objects well, and others poorly. Matching color of the light isn't enough -- mixing monochromatic light of two wavelengths (say, appropriately selected blue and yellow) are enough to make a "white" light, but almost any object will look wrong. An object reflecting only, say, red above 650nm, would appear black, since there's no red light for it to reflect; a broader spectrum red might appear yellow, but nothing will appear true red.

White LEDs typically have a narrow blue peak from the LED proper, and a broad yellow peak from the phospor coating, which combine for "white", but have serious red and minor green/cyan deficiencies. High-CRI LEDs have multiple phospors to broaden the yellow peak more, reducing (but not eliminating) these weaknesses. Other light sources have their own characteristic spectral deficiencies (including incandescents, even halogens, which while often touted as standard (thanks to CRI), are rather weak in blue due to their low CCT).

The most common measure for "properness" of a spectrum is CRI, which is based on accurate rendition of a series of standardized dyes compared to a blackbody source of equivalent temperature (roughly, color) -- there are numerous reasons it's a bad system, but it's in use, and a whole lot better than nothing. However, anything properly selected for high reflectance in the LED's weak points and weak reflectance in the LEDs strong points will allow similar comparison of LEDs to halogens. For those of us who experiment with using red and/or cyan LEDs to "fill" the white LEDs' spectrum, but can't afford a spectro, this info should be pretty damn helpful -- observe the difference between a box of crayons under halogen and LED lighting, see which crayons are most different, look at the SPDs, and you can see where your wavelength deficiencies are.

Re:Who cares about sRGB? (1)

Chris Burke (6130) | more than 2 years ago | (#37462090)

Well, what's cool is that the first image in the blog post is a graph of the spectra of each of the crayons.

He did WHAT!!!???!!! (1)

grep -v '.*' * (780312) | more than 2 years ago | (#37463494)

"Using a monitor calibration tool and the Argyll 3rd party software he evaluated a box of 24 Crayola crayons..."

But...but ... that's our secret recipe, just like Kentucky Fried Chicken (excuse me, KFC) or Coke (excuse me, Coca-Cola (Excuse Me, Coca-Cola Classic)). Now kids can just use it for free on the intertubes?!? And *no* royalties or renewables to parents to renew!!??!!??

Release the lawyers!! Let the DCMA slaughter begin -- Leave No Chemist Standing!!

(...and someone get me Jackson about that D-M-R + microwavable chip thing he was blathering about again.)

Not a spectrophotometer (1)

brillow (917507) | more than 2 years ago | (#37464328)

A monitor calibration tool is not a spectrophotometer, its a spectroradiometer.

Re:Not a spectrophotometer (0)

Anonymous Coward | more than 2 years ago | (#37466754)

It's usually just a colorimeter.
www.hunterlab.com/appnotes/an03_95r.pdf

Spectrophotometer? (0)

Anonymous Coward | more than 2 years ago | (#37466372)

For me a spectrophotometer is an AAS (Atomic Absorption Spectrophotometer) or an ICP-OES (Inductively Coupled Plasma - Optical Emission Spectrophotometer) or, if you want really low levels, an ICP-MS (Mass Spec)... Looks like working 15 years in an analytical lab kind of skews your view on more common equipment :-)

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