Plz explain 460nm peak light

[ZoWhat]

I dont understand why in the LED-world a 460nm light is BLUE

But in the Metal-Halide world the same 460nm "peak" looks most WHITE

Examples:

Hamilton 20k MH with light looking mostly WHITE

460nm LED Diode that definitely looks BLUE

 

[miPapareef]

For light, the addition of wavelengths makes white. That Hamilton bulb has green, yellow, orange, red at higher levels than the LED. Add all those color wavelengths together and you get white.

 

[saltyfilmfolks]

Color mixing.
You can make an rgb light look white. (Not when you look at it but the subject it lights.)
Some with a television with rgb pixels.
The second example has no G R U O

 

[Amoo]

You're not even comparing apples to apples, or debatable even apples to oranges here.

You're asking about the entire spectral output of a bulb with 20K color and a 460nm peak color vs a single point source light designed specifically to emit light at a certain wavelength, no more, no less.

460nm is 460nm regardless, and the two will look identical regardless of source. Once you start adding other spectrums to the mix it is always going to look different.

 

[ZoWhat]

So what you're saying is pure white light, say 3to4-kelvin light (you see in bright white light bulbs in lamp fixtures) is the mixture of many, if not all nm wavelengths???? Say 400nm to 700nm all emitting together?

And the absence of any nm wavelength light is black?

All my Art Teachers FAILED me bc I think they all said white is the absence of ALL color.


.

 

[saltyfilmfolks]

So what you're saying is pure white light, say 10kelvin light is the mixture of many if not all nm wavelengths???? Say 200nm to 800nm all emitting together?

And the absence of any nm wavelength light is black?

All my Art Teachers FAILED me bc they all said white is the absence of ALL color.


.

Yes.

Bottom is a close 5600k

By changing the ratios you change the color.

White is relative , not actually a color. 3800 k to 10- and a even tonyour eye, somtimes a full spectrum 20 appears white (like in a valley with no direct sun) your eye just compensates.

The color white on a paper is the reflection of all the spectrums of light.
Black is the absorption of all the spectrums.

Dark in a room is the absence of all spectrums of ligh.

 

[Amoo]

So what you're saying is pure white light, say 10-12kelvin light is the mixture of many if not all nm wavelengths???? Say 400nm to 700nm all emitting together?

And the absence of any nm wavelength light is black?

All my Art Teachers FAILED me bc I think they all said white is the absence of ALL color.


.

It can be both it just depends on the application. It could be the reflection of all different colors, it could be the emission of certain wavelength. It could be the emission of a combination of wavelengths that appear white. Combine that with the fact "white light" means something different to everybody.

If you look at the K ratings of most bulbs in the household they are classified as Warm White, Cool White, Natural White...etc. These are all usually between 3500-6500K.

 

[miPapareef]

All my Art Teachers FAILED me bc I think they all said white is the absence of ALL color.

For paint or other pigment (light absorbing) material, your art teacher’s statement would be right. The more color pigments you mix together the more black you get.

For light emitting materials, like the sun, bulb or LED, the more colors emitted the more white it appears.