I always refer back to it when these type of questions come up. It seems to me the best method on figuring out what strength wavelength compares in brightness to a different wavelenth's strength.
"200mw 635nm red = 23.827mw green
200mw 650nm red = 10.680mw green
200mw 660nm red = 5.721mw green
1W 445nm = 99.270mw green
600mw 405nm = 9.6077mw green
Using chroma and taking Rayleigh scattering into account"
OK - so these are the accepted accurate numbers?
Beam: (635nm 200mw) vs. (532nm 23.82mw)
Beam: (650nm 200mw) vs. (532nm 10.68mw)
- Looks dead on to me. You can plug in the rest of the values, they should all work. So where's the flaw?
And those are the values that the calculator generated.
Something is just messed up somewhere in your math is all i'm saying. If the numbers for the 'dot' aren't right, then neither are the ones accounting for Rayleigh scattering. (which will be based on the numbers for the dot with a correction factor applied.)
Your calculator comparing 375mW of 445nm, compared to ? mW of 532nm and set on beam fills in the blank as 26.17mW of 532nm being equal to 375mW of 445... Which I can tell you is nowhere near right..
So like I said.. Something is messed up somewhere in your math. You can get mad at me all you want, but it's still true.
It looks to me like the calculator is producing exactly the same values as Chroma with the factors accounted for manually. IE (as Kevlar said):
"200mw 635nm red = 23.827mw green"
Beam: (635nm 200mw) vs. (532nm 23.82mw)
So again - looks like it's getting it bang on. If the blue values aren't equating to Chroma's with Raleigh factoring, that's not surprising. There's some debate about the accurate values for blue. But remember, my calculator doesn't "calculate" that part of the function - it references it from CIE tables. There are different CIE tables, and from my understanding, the primary difference is the blue range.
I *think* Chroma uses the CIE 1931 or 1975 tables.
I *think* my calculator uses CIE 1978 tables.
(I don't remember with 100% confidence from memory - but that's my best recollection)
I don't particularly know the tables I'm using to be better than Chroma, they were simply the most recent set of data I was able to access when I made the tool. The only difference, if there is any difference, should be in blue range.
That said, if people are dead set on this calculator matching Chroma, it would be trivial for me to swap the datasets and use the CIE 1931 tables that Chroma uses. In fact, I think I actually have both tables already in the database, and it would just be a "flip of a switch".