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Christmas Tree Lights

thatguywhojuggles said:
I have a juggling ball that has LED lights in it. When you turn it on, it cycles through like 7 diffferent colors, including white. I was very excited to discover, when I opened it up that there were only 3 LEDs making those 7 colors.

Can you guess the colors?


Edited to add: When I worked for Mad Science, teaching kids about science, I would use my juggling ball to teach about light.
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You worked for Mad Science? Did you know Bob Lewis?
 
casebro said:
Printing and monitors are both examples of additive
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You can see the image on a printed page better in the light; you can see the image on a monitor better in the dark.

If you mix together enough differently colored ink, you get black. If you "mix" together enough differently colored pixels, you get white.

Printing is subtractive; monitors are additive.
 
casebro said:
Printing and monitors are both examples of additive, filters on cameras are subtractive. The magenta and cyan are simply more technical names for redish and blueish. Using green instead of yellow is more a matter of choice of pallate.
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Not even remotely true.

Magenta and cyan are distinct colours, and are not even close to blue or red (cyan is, specifically, a combination of blue and gree, magenta is is red and blue).

Camera filters are not subtractive, they are additive. "Additive" and "subtractive" are specific, technical terms rooted in the physics of how light behaves. I strongly suspect that you have no real idea what they mean. Try doing a bit of research, particularly on the difference between direct (transmitted) and reflected light.

And don't even try to tell me I'm wrong on this. I spent 3 years at university studying fine arts, with an emphasis on Photography. I've forgotten more about colour theory than you're likely to ever know.
 
luchog said:
Not even remotely true.
Magenta and cyan are distinct colours, and are not even close to blue or red (cyan is, specifically, a combination of blue and gree, magenta is is red and blue).
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And just to be really technical, true cyan light is not really a combination of blue and green, but the human eye can't tell the difference.
 
Right, cyan can be seen with an additive mix of blue and green, but also with a stimulus of about 525 nm. Magenta is a true mixture of red and blue, not to be found on the visible spectrum.
 
So, if I have blue paint, and add yellow,they add up to green.
If I have green light,and add yellow, it should subtract and I'll get blue????
Then, I'll shine a green light on a green opaque surface, I'll get....black...no..WHITE!!...brighter green???

Maybe it's my math skills....maybe 'additive' and 'subtractive' don't mean what I think they mean...anybody care to tell me why 'least common denominator' means a little number, not the rarest number?

Anybody want to here the story about 'Nookie' Green? I think it is additive, what with her red hair and green heels= very funny

Okay, so I have a color wheel. mixing the 2 colors at 2:00 and 10:00 will give me noon, if paint, and 6:00 if gels on a lamp?
 
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casebro said:
So, if I have blue paint, and add yellow,they add up to green.
If I have green light,and add yellow, it should subtract and I'll get blue????
Then, I'll shine a green light on a green opaque surface, I'll get....black...no..WHITE!!...brighter green???

Maybe it's my math skills....maybe 'additive' and 'subtractive' don't mean what I think they mean...anybody care to tell me why 'least common denominator' means a little number, not the rarest number?

Anybody want to here the story about 'Nookie' Green? I think it is additive, what with her red hair and green heels....
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err...

Pay attention now:

Camera filters are not subtractive, they are additive. "Additive" and "subtractive" are specific, technical terms rooted in the physics of how light behaves. I strongly suspect that you have no real idea what they mean. Try doing a bit of research, particularly on the difference between direct (transmitted) and reflected light.
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emphasis mine.
 
casebro said:
anybody care to tell me why 'least common denominator' means a little number, not the rarest number?
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Because it's the least[1] (common denominator) and not the (least common) denominator.

[1] smallest (ie less, lesser, least), as opposed to "greatest"
 
casebro said:
So, if I have blue paint, and add yellow,they add up to green.
If I have green light,and add yellow, it should subtract and I'll get blue????
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Mixing paint or printing inks is called subtractive color mixture because pigments selectively absorb(subtract)certain wavelengths and reflect what you see. Red paint absorbs everything but red and reflects red. Green paint absorbs everything but green. Mix the two and they absorb almost all colors, yielding black(ish).
If you mix lights additively, you summate the waveforms so that red and green produce yellow on your tv screen. The little dots are so small and close together that they appear to fuse. A French art school, Pointillism, did this with great effect. See Seurat, pour example.
These facts about mixing colors are very much confused by people who study art and printing.
 
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Okay, Okay, you can stop Pointillificating.

But I'd appreciate direct answers to my color wheel clocking question, and my green light on green paint query.

I did figure out on my own the question of "least common", but not for several years after algebra class. I learned something from that- Now when someone asks me something a second time, I try to use different words- "smallest" would have meant a lot to me. I aced geometry and trig, but still can't figure algebra... Damn pig-headed teacher.

I'm glad nobody wants to hear the "Nookie" Green story- I flunked typing.
 
69dodge said:
If you mix together enough differently colored ink, you get black.
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No, you get brown. That's why feces is that color: it's a mixture of a bunch of colors.

luchog said:
I've forgotten more about colour theory than you're likely to ever know.
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Apparently, you've also forgotten quite a bit about politeness.

casebro said:
If I have green light,and add yellow, it should subtract and I'll get blue????
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No, light is additive.

Then, I'll shine a green light on a green opaque surface, I'll get....black...no..WHITE!!...brighter green???
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The surface will subtract the nongreen light, which leaves green.

Maybe it's my math skills....maybe 'additive' and 'subtractive' don't mean what I think they mean...
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The problem is that there are three parameters involved. Pure green pigment subtracts from nongreen colors, but does nothing to pure green.

anybody care to tell me why 'least common denominator' means a little number, not the rarest number?
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An LCD isn't a little number; it's always greater than or equal to the original numbers. To be a denominator, it has to be a multiple. Something which is a denominator for both fractions is common (as in "occuring both places"). There are a bunch of common denominators, and the smallest one is the LCD.

Jeff Corey
If you mix lights additively, you summate the waveforms so that red and green produce yellow on your tv screen.
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You sum the waves? No.
 
casebro said:
...anybody care to tell me why 'least common denominator' means a little number, not the rarest number?
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When I was at school over here it was referred to as the lowest common denominator. Less potential for confusion, I guess.
 
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