Kodak Portra film has both a Green and Red sensitivity of about 2.0 relative log E with a maximum speed of 2.5, so it is pretty sensitive in the region of the visible spectrum of Sodium lamps. That is how it works to give us a yellow in the final print.
I know color reproduction well enough to design films and papers and to be the person responsible for color reproduction of 3 major products AAMOF.
To paraphrase Klaatu in the original movie "I know the math well enough to navigate between planets!" I used this in answer to one of the 24 or so PMs today about this thread. I hope that the quote is not lost on you all and explains my growing exasperation.
Why? It is about perceiving a color, which only a sensation. You allow that that Magenta is non-spectral; no single wavelength will cause us to perceive it. Our minds create it from Red and Blue. It is only a sensation. There is no Magenta wavelength, so it is not a natural color. So what's the problem with saying that other colors can be formed (in our heads) from combining colors?Quote:
Get rid of that red herring about perception and reality.
BTW, are you sure that herring's red? You might just be perceiving it that way.
Get this, Q.G. Nobody has tried to explain everything about color using an additive or subtractive tri-color model.Quote:
Whether you call it colour, energy or frequency is irrelevant. Irrelevant, because it doesn't change anything about the error that is trying to explain everything about colour using an additive or subtractive tri-colour model.
That's what you have missed.
That is what you have missed.
But have you noticed that multi-layer colour materials were pressed into service to explain something that has nothing to do with multi-layer colour materials?
Actually, I usually don't.Quote:
And that's why you always get involved in this sort of thing.
If you're very scientific about a sucky photograph, it's still a sucky photograph...EC
In a subtractive system yellow is already there.
No one on "the other side" ever said that yellow is not the color expression of a single wavelength, too. Only that the color can be perceived by combining Red and Green.
It's the same reason many of us won't hesitate to cut in line on the highway whereas we would never do it in person. It's much easier to ignore the horn sounding than it is to ignore someone screaming at you in front of a hundred other people, some of which are equally impacted by your rudeness.