This would all be great and applicable to an audio discussion if it
were true, but it's not. You may say that "680nm is red" but you won't
get a consensus on the topic. If you take a stack of say 50 color
samples ranging in tiny increments from yellow to orange and ask 100
different people to pick out "the red one" you will probably get about
5 or 10 different answers. Most of the responses will fall around the
two or three in the middle, but not all of them. Yes, I have actually
done this (with 20 people, not 100) and my idea of "red" was different
from the guy next to me. Not by much, but by enough to throw this
"objectivity" argument out the window. When you draw a picture of a
rainbow you only need six crayons but a real rainbow has an infinite
number of colors and there's no solid black line lithographed between
them.

ulysses


In article ,
wrote:

George Gleason wrote:

once a standard is set , say RED is 680 then no matter what each person
sees they will always see the same thing when we get to 680
and it becomes moot what they are seeing as long as we both can agree that
680 is 680
individual perception is less important than collective agreement on
standerdized, testable and repeatable concepts

Yeah. that's the point exactly. If someone shines 680 and says,
That's red. It doesn't matter what goes on in the person's brain.
I mean inside my brain I may see a certain color I call "red"
and another person may be perceiving a response to 680 that *I*
would call "green", but it doesn't matter because they also
would label the thing they see at 680 as "red". I can't know
what's going on in their brain. I only know that when 680
shines we both label what we see as "red".

So the 680 as "red" is objective. What I actually experience
is subjective and in a sense can't be known or compared.

Benj
(Of course it gets more interesting in the Near IR where
some people can see "deep red" and others see "nothing".)