filmscanners: metamerism and Epson 2000P

["Eli Bowen" <elbow@microsoft.com>]

From: "Frequently asked questions about Colour Physics"
http://www.colourware.co.uk/cpfaq.htm

"Metamerism refers to the situation where two colour samples appear to
match under one condition but not under another; the match is said to be
conditional. Metamersim is usually discussed in terms of two illuminants
(illuminant metamerism) whereby two samples may match under one
illuminant but not under another. Other types of metamerism include
geometrical metamerism and observer metamerism. Two samples that
conditionally match are said to be a metameric pair. If two samples have
identical reflectance spectra then they cannot be metameric - they are
an unconditional match."

>From what I have read, the Epson 2000P inks are more metameric than most
inks, so it is important to proof Epson 2000P prints using the
illuminant under which they will be displayed (this is always true, but
especially so with the Epson 2000P.

Here's a page specifically devoted to metamerism and the 2000P:
http://www.tssphoto.com/sp/dg/2000p/metamerism.html


-----Original Message-----
From: Frank Paris [mailto:marshalt@spiritone.com]
Sent: Tuesday, January 23, 2001 6:14 PM
To: filmscanners@halftone.co.uk
Subject: RE: filmscanners: SS4000 and LS-2000 real value?


> -----Original Message-----
> From: owner-filmscanners@halftone.co.uk
> [mailto:owner-filmscanners@halftone.co.uk]On Behalf Of Laurie Solomon
> Sent: Tuesday, January 23, 2001 7:51 AM
> To: filmscanners@halftone.co.uk
> Subject: RE: filmscanners: SS4000 and LS-2000 real value?
>
>
> It is my understanding that ... the color of the [Epson 2000P] inks
tend
to
> change colors under different lights reflecting ff of them from
different
> angles.

This happens for most objects, not just Epson 2000P inks.

> I believe it is called menorism (sp?) or something like that.

Are you talking about metamerism? What you describe at any rate is not
metamerism. Metamerism is two specimins that match under a specified
illuminator and to a specified observer and whose spectral reflectances
or
transmittances different in the visible wavelengths. Metamerism is a
good
thing, not a bad thing. It is how you get color matching even if the
primaries aren't the same in two devices.