cyan?

What color is a cyan light?Green? /ubbthreads/images/graemlins/icon3.gif

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coachbigdog said:
What color is a cyan light?Green? /ubbthreads/images/graemlins/icon3.gif

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blue/green or maybe labeled "turquoise" kinda like this guy's face....... /ubbthreads/images/graemlins/grin.gif maybe a little darker. most people will see and say green if looking at the light....until you put an actual "green" light beside it.

A true cyan is a blue-green color, with a dominant wavelength (where you would point to on a color chart) of around 490nm.

This old style of cyan LED is known as "Tokyo Blue", as it was most often used in traffic signals in Japan, in the "go" part of the signal.

These days, most LEDs they call "cyan" have dominant wavelengths of 505-510nm, which is a distinctly greener shade of blue-green. Cyan LEDs are made more greenish on purpose to appeal to the most frequent user of such LEDs - United States traffic signal manufacturers. They appear green to the eye, yet emit enough blue to be visible to somebody with red-green color blindness.

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The_LED_Museum said:
A true cyan is a blue-green color, with a dominant wavelength (where you would point to on a color chart) of around 490nm.

This old style of cyan LED is known as "Tokyo Blue", as it was most often used in traffic signals in Japan, in the "go" part of the signal.

These days, most LEDs they call "cyan" have dominant wavelengths of 505-510nm, which is a distinctly greener shade of blue-green. Cyan LEDs are made more greenish on purpose to appeal to the most frequent user of such LEDs - United States traffic signal manufacturers. They appear green to the eye, yet emit enough blue to be visible to somebody with red-green color blindness.

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/ubbthreads/images/graemlins/ooo.gifboy do i feel like an ameteur......... /ubbthreads/images/graemlins/blush.gif

what he said. /ubbthreads/images/graemlins/grin.gif

i recientally got a 3W white and a 3W cyan from Wayne (Dat2Zip). the White is intense at 750mA.(dorcy 1xAA running a 3.6v LION and a faren optic), anyway, I digress... The cyan emitter I gat is almost green, Not as green as my 532nm laser pointer, but not nearly cyan as some 5mm cyan leds I have. Wayne said that there is a large range of color in the batch labeled cyan.

.02

Jeff

Thanks everyone!

A market where the money is important ;

Green is brighter than Cyan.
Cyan is brighter than Blue.
Blue is muuuch brighter than Royal blue.

As the wavelength become longer in Blue LEDs (InGaN),
it turns to be in Cyan ( Bluish Green)

So, the traffic signal is in Cyan.

The color blinded people recognise the traffic signal ;
Red signal (629nm)is Black (dark): STOP
Cyan signal (509-530nm) is White (bright): WALK

Am I correct ?

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warren said:
Cyan signal (509-530nm) is White (bright): WALK

Am I correct ?

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I think it should read:
Cyan signal (505-520nm) is White (bright): WALK

530nm is a distinct shade of non-whitish lime green, and LEDs with a wavelength range of 520-530nm are sold as InGaN green ones.

Just my opinion mind you; individual results may vary.

WildRice,

I have a cyan 1 watter that goes green when the batteries are close to pooping out. You might want to check the load voltage and current draw. I also popped one in a dorcy 1AAA where it is definitely a different shade of cyan but is also not being driven as hard. It is more to the photographic cyan than the others which are more greenish.

This is fairly close to how my 5W cyan Luxeon appears to the eye (perhaps just a bit too blue in this photograph). The dominant wavelength (where you would point to on a color chart) appears to be right around 495nm.

That bright spot near the top is the beam from a 16mW argon ion laser; 488nm, single line, TEM00.