How much power does a led emitting 6000 mcd...

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How much power does a led emitting 6000 mcd of 465 nm blu light in a 20 degrees angle converts into luminous energy (Watts)? All the light the led emits is captured, so I don't care how wide the beam is, just how many watts I can gather.

I tried searching for led efficiency but all I find is lumen/watt. The problem is that it is calculated for 550 nm light, and I don't know how to calculate that for blue light. Any ideas?

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Anyone has some advice?

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Just give me an advice

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Please

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https://en.wikipedia.org/wiki/Candela#Explanation

<--wavelength dependent formula

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>>7809043

According to my math, one of these leds https://www.adafruit.com/products/301 outputs only 0.01 W. Is this even possible?

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>>7809811

yes, most commong 5mm leds are 0,01W/0,25W/0,6W/1W

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>>7809818

Are you talking about the power they use or about the power they output?

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>>7809825

if you tried to integrate the emitted wavelengths to find out the power it emits 0,01 sounds like a reasonable result.

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>>7809867

just write down or screencap what you're trying to find out and i'll help. also post a pic of your calculations

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>>7807680

>I don't know how to calculate that for blue light.

It's not a calculation; light follows aberrant quantity rules. Detection depends on the composition of the measuring body, wattage inclusive.

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>>7809887

I'll explain everything:

According to this paper ( http://emedicine.medscape.com/article/1894477-overview#a4 ) I need 10 mW/cm^2 of blue light at 458 nm (I found those 465 nm blue led: https://www.adafruit.com/products/301 ), over an area of 0.10 m^2 (30 * 30 cm).

Now I can't tell how many leds would I need to get those 10 W.

If every single of those leds output 0.01 W I'd need 1000 of them, but that seems overkill.

Anyway this is how I calculated it:

6 cd / (683 * 0.1).

I got the last number from this site ( http://www.cvrl.org/lumindex.htm ) for 465 nm light.

That gives me 0.1 W/sr.

In the leds vendor page the viewing angle is listed to be 20 degrees (10 + 10).

So it covers a solid angle of (assuming a sphere of radius 1): PI * (sin 10°)^2 / (1^2), which is 0.1 sr.

It follows that the total power that a single led emits is 0.1 W/sr * 0.1 sr = 0.01 W.

Did I get it wrong?

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Help?

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>>7810365

Me!

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>>7809927

i tried this for 555nm and checked with this website to make sure i did everything correct.. then i did the same calculation for 480nm and i got 0,012W which is either correct or we are both idiots. http://www.translatorscafe.com/cafe/EN/units-converter/illumination/9-11/lumen%2Fcentimeter%C2%B2-watt%2Fcentimeter%C2%B2_%28at_555_nm%29/

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>>7811317

:( please

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>>7811703

Thank you, for some reason it didn't show me your reply. That is a lot less than what I was hoping.

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