color matching functions

[Saeideh Gorji]

Dear freinds,
Hi

I am confusing about r light in color matching functions, the
wavelength of r is 700nm however the obtained color matching is almost
zero at 700nm! so what is the roll of r in color matching functions
while we don't see a monochrome light at 700nm!!

Saeideh Gorji

[ImageAnalyst]

Post by Saeideh Gorji
Dear freinds,
Hi
I am confusing about r light in color matching functions, the
wavelength of r is 700nm however the obtained color matching is almost
zero at 700nm! so what is the roll of r in color matching functions
while we don't see a monochrome light at 700nm!!
Saeideh Gorji

------------------------------------------------------------------------------------------------------------------
Saeideh Gorji
What color matching function are you talking about? Give an
equation. Also, who says you can't see light at 700 nm? And who says
that red is 700 exactly? A helium neon laser emits a pretty red beam
at 632 nm. I'm not sure where you're getting your information but it
seems suspect or downright wrong (like that viral stuff going around
about magenta not being a real color).
-ImageAnalyst

[g***@yahoo.com]

Post by Saeideh Gorji
Hi
I am confusing about r light in color matching functions, the
wavelength of r is 700nm however the obtained color matching is almost
zero at 700nm! so what is the roll of r in color matching functions
while we don't see a monochrome light at 700nm!!
Saeideh Gorji

---------------------------------------------------------------------------­---------------------------------------
Saeideh Gorji
What color matching function are you talking about?  Give an
equation.  Also, who says you can't see light at 700 nm?  And who says
that red is 700 exactly?  A helium neon laser emits a pretty red beam
at 632 nm.  I'm not sure where you're getting your information but it
seems suspect or downright wrong  (like that viral stuff going around
about magenta not being a real color).
-ImageAnalyst

I talking a bout standard color matching functions of the CIE 1931.
the stimulus are monochromatic lights of wavelenght r=700, g=546.1 and
b=435.8, however if you see the obtained functions the sensivity of
standard observes has been reported zero at 700 nm! now how this light
has been used for obtaining the color matching functions when the
observers can't see it!?

[Gernot Hoffmann]

Post by g***@yahoo.com
I talking a bout standard color matching functions of the CIE 1931.
the stimulus are monochromatic lights of wavelenght r=700, g=546.1 and
b=435.8, however if you see the obtained functions the sensivity of
standard observes has been reported zero at 700 nm! now how this light
has been used for obtaining the color matching functions when the
observers can't see it!?

The CMF for r-bar is very small at 700nm, but not zero:
http://www.fho-emden.de/~hoffmann/matchrgb.txt

This is in fact an EPS graphic (just rename as EPS and
show by e.g. Photoshop or other PostScript interpreters.

By the way: your question is very reasonable. As a consequence
it can be said that the purple line is practically somewhat fictional.
Real world purples (magentas) are inside the chromaticity dia-
gram.

Best regards --Gernot Hoffmann

[Gernot Hoffmann]

Post by Saeideh Gorji
Dear freinds,
Hi
I am confusing about r light in color matching functions, the
wavelength of r is 700nm however the obtained color matching is almost
zero at 700nm! so what is the roll of r in color matching functions
while we don't see a monochrome light at 700nm!!
Saeideh Gorji

Red at 700nm is visible under laboratory conditions, but hardly in
real life, if the power is the same as for other monochromatic
spectra in a viewing experiment.
See also p.8 here:
http://www.fho-emden.de/~hoffmann/ciexyz29082000.pdf

Best regards --Gernot Hoffmann