What's the wavelength of pure green?

[steve001]

Exposing my complete ignorance of color theory here: Red green and blue are the primary colors right? I guess the source ultimately at least for our planet is the sun. Is RG and B the same for other stars? Are the primary colors constant throughout the known visible universe? What device or system can represent or display perfect example of R G and B. Or is there always some variation?

If you are an artist... red, blue, green are primary colors useful for creating a range of colors, but those 3 cannot create all colors that one sees when sunlight passes through a prism so in that way they are not primary colors. Autochrome photography used different primary colors.
For more information do a web search for the questions you've asked.

 

[Pman]

Doesn't matter what others think. Buy what YOU like. If others don't agree so what. Just because you buy a 520nm doesn't mean it's going to be perfect 520nm. I don't know if there has been testing done to see how much a 520nm shifts the more you push it but with my eyes I definately see the blue tint my 515nm units and one of them is pretty pronounced. For all I know the others are higher than 515 and that bluer one is actually 515nm. No way of knowing without actually measuring.
This is where building your own comes into play so you can decide for yourself which diode to use if you bought more than one and how much to push it.
Regardless, to get a basic idea of the difference between a 515, 520 and 532 it's best to see them in person at about the same output equivalent to the others brightness including the lens that you would use. Can get a basic idea by looking at a lot of pics and other things like the relative brightness calculator. Might be surprised at the difference between similar wavelengths though when you factor in power density/divergence and if you can't stand the way the dot looks that will narrow down the choice. It can be easy or complicated. Unfortunately for you it's very complicated

 

[Isaac Clarke]

why can't he have all? ( references to a taco ad)

 

[BowtieGuy]

why can't he have all? ( references to a taco ad)

You can have it all!
If you have enough $green$, you can have all the green you want.

 

[joeyss]

I have a 520 from dtr and it makes 532 look yellowish ( something I theorized like 2 years before when i lit my room up with a 100mw 532 and saw it slighty yellow tinted to the green after like 5 mins)

I'd say 520 looks true green.

 

[Vision]

I have a 520 from dtr and it makes 532 look yellowish ( something I theorized like 2 years before when i lit my room up with a 100mw 532 and saw it slighty yellow tinted to the green after like 5 mins)

I'd say 520 looks true green.

520 looks peaceful.:angel: