Red/Cyan-Green/Royal Blue in same light???

Kind'a seems trivial, but has anybody ever thought about doing a light with a Red, Cyan or Green, and Royal Blue emitter in a triad assembly?

Or any assembly of 3 different colors...

ElektroLumens?

I have to admit, it probably won't be any good of a utility light, save for the coolness factor...

IF you combine Red, Cyan, Green together.. it's pretty redundant. Cyan and green is almost the same colour. Almost...

If you combine Red, Cyan/green, RB together, and all the 3 at the same time... you will get Purplish Green? Urgh....

Frankly speaking, even if I am to have any triad of colours, they must at least be useful. RB is good for flourcensing stuff up. White for general lighting. Amber for contrast in stuff. These 3 won't mix well together though....

True... I do wonder, though, if night vision would be more enhanced with white and cyan together...

Maybe one of these days, I'll experiment with a collimated 5W white LD LS in the center, and 4 uncollimated 1W Cyan HD LS around it... Would probably make for an interesting setup, nonetheless...

If you ever have seen one of those 3-D movies you had to wear a pair of red/green glasses, you will know what it looks like without them...

Now add a third shadow...

Actually, a Red/Blue/Green combo (in proper perportion) should give you WHITE !

The problem in doing this is the differing (lower) voltage requirements of the Red family Luxeons. I suspect it could be managed by building separate converters for each LED to keep them in sync as the batteries deplete..

Originally posted by Slick:
Actually, a Red/Blue/Green combo (in proper perportion) should give you WHITE !

The problem in doing this is the differing (lower) voltage requirements of the Red family Luxeons. I suspect it could be managed by building separate converters for each LED to keep them in sync as the batteries deplete..

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<font size="2" face="Verdana, Arial">I thought the primary colors were red, yellow, blue ? If you put a variable resistor on each light, or multiple voltage regulators, one on each light, you could make any color, including white.

Wayne J.

Still each LS gives out different amount of lights. Adjusting them for perfect white would be a PITA. (Pain in the ***)

You will keep having the problem that the beams will overlap only at a fixed distance...

Here is a pic Craig shot of the Eternalight Raven:

Although there is a white section in the middle, the edges will have different colors, depending on the location in the beam...

For additive colors like lights wouldn't they be red green and blue?

Yes you can make a sort of a white light with a red green and blue light. It will look a little strange since it will be made up mostly of 3 bands of monochromatic light instead of a more even distribution.

Also, any shadows will be multi-colored

If you're not looking for exact colorization you should just try hooking them up. I don't think it will be that bad if it's a little on the blue side? Adjusting them would be necessary to get it closer to white, but you'd just be doing by eye

Psst. I did this:

http://www.ledmuseum.org/bike1.htm

The light that it casts is a pretty good white, but shadows of anything close to the source are pretty funky.

-Jon

the primary colord for light are red green and blue, whereas the primary colors for colors are red yellow blue.

right?

yes, that is correct. The first time you make yellow by mixing red and green is a strange experience

Of course thats light, if you mix red and green pain you get brown!

And since yellow is red and green, you can get a white by mixing yellow and blue LED's. I've done this. It works.

Are there yellow Luxeons?

Originally posted by Rothrandir:
the primary colord for light are red green and blue, whereas the primary colors for colors are red yellow blue.

right?

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<font size="2" face="Verdana, Arial">Yes, computer monitors & TV's also work on the "RGB" scale too..

James S - Lumileds makes an amber luxeon. It is from the same chemical family as the Red's, so be sure to isolate your slug..

Originally posted by Rothrandir:
the primary colord for light are red green and blue, whereas the primary colors for colors are red yellow blue.

right?

Click to expand...

<font size="2" face="Verdana, Arial">I think that's only partially right. Our eyes have three types of color sensitive cones, each sensitive to a of range wavelengths.



As you can see from this graph, a yellowish-green wavelength (say around 550nm) stimulates both the red-sensitive and green-sensitive cones about equally. Our eyes would see the same color if you mixed a greener wavelength with a redder wavelength that ended up stimulating those cells in the same proportion.

You can even get a sense here of why it's difficult to make a consistent white LED. Here is Mike from Inretech's measured spectrum of a white Luxeon:



The blue spike comes from the LED itself, and the greenish-yellowish mound comes from the phosphor coating on the LED that is being stimulated by the blue light from the LED. Mix greenish-yellow with blue, and what do you get? A nice hot blue white, if you're lucky. If you're unlucky, you see too much phosphor and you get the famous pee-green effect. Too little, and you see too much blue.

This spectrum is very unlike this incandescent (2100° K) lamp, which has much less blue and much more red.



Hence objects can appear very different under different "white" lights. Light on the left is double-barrel 4-AAA incandescent flashlight. On the right is a 1W white Luxeon.

I have made a couple of multi-coloured torches. One was a production mistake when I got blue and green LED's mixed up in a BT2 whilst it was being built; however it was a very pleasant torch to use, as the mixed output of the two colours was like cyan.Shadows of objects close to the torch show eerie green and blue edging or are completely green or blue.
Oranges & Lemons is another torch I've tried using some LED's left over from a production run, installed into a smart "Battrex" 2AA torch with direct drive. The beams of the Toshiba LED's do not converge in the same way as for the Nichias and the effect is interesting. If you approach a user of O & L at night, the torch appears to twinkle between yellow and orange.
I've yet to experiment with any other colour combinations, but on a whim I might use up my oddment LED's up to build something totaly unique!

Originally posted by Rothrandir:
the primary colord for light are red green and blue, whereas the primary colors for colors are red yellow blue.

right?

Click to expand...

<font size="2" face="Verdana, Arial">Close. RGB is definately correct for light. (This is why computers usually define colors in the RGB colorspace.)

I believe the primary colors for paints/dyes/etc. are cyan, magenta, and yellow. (Cyan and magenta are close to read and blue, but not quite. Most importantly, they are the complimentary colors of RGB.) This is why you see references to CMYK color spaces for printing. Cyan,Magenta,Yellow, don't know what K is short for but K is black ink. (Because it's very tough to get a good black from most CMY inks, the best you can do is normally an ugly dark brown.)

Originally posted by Entropy:
</font><blockquote><font size="1" face="Verdana, Arial">quote:</font><hr /><font size="2" face="Verdana, Arial">Originally posted by Rothrandir:
the primary colord for light are red green and blue, whereas the primary colors for colors are red yellow blue.

right?

Click to expand...

<font size="2" face="Verdana, Arial">Close. RGB is definately correct for light. (This is why computers usually define colors in the RGB colorspace.)

I believe the primary colors for paints/dyes/etc. are cyan, magenta, and yellow. (Cyan and magenta are close to read and blue, but not quite. Most importantly, they are the complimentary colors of RGB.) </font><hr /></blockquote><font size="2" face="Verdana, Arial">Actually, all of this confusion comes from the way that our pigments work. what may look like blue is actually reflecting more than just blue. If a blue crayon that actually only reflected back blue light, and a yellow crayon was also perfect in it's reflective characteristics, were to overlap, you'd actually get BLACK!

It's true - the 3 primary colors of subtraction (i.e. reflected as opposed to projected color) - Cyan, Magenta and Yellow are black when added together. Blue is Cyan and Magenta, BTW

Here's a good article about it, and light in general. A little urbane, yes, but helpful nonetheless:

How Light Works

True... I do wonder, though, if night vision would be more enhanced with white and cyan together...

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<font size="2" face="Verdana, Arial">Absolutely not. Any color except red below around 620nm will disrupt your night vision.

http://thelightsite.cruxial.com/qa.htm#nightvision

Max - Good explanation!

Hey Max, what IS the true color of that flower?

Originally posted by Orion:
Hey Max, what IS the true color of that flower?

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<font size="2" face="Verdana, Arial">Under daylight, the tips are white, and the colored parts are much more red than purple.