Re: Good demonstration of metamerism?
Re: Good demonstration of metamerism?
- Subject: Re: Good demonstration of metamerism?
- From: "john castronovo" <email@hidden>
- Date: Mon, 14 Jun 2010 17:01:44 -0400
One that works quite well is to have two black and white prints made,
one on traditional silver halide paper and one on color print paper.
They can be made to match, but only under one kind of light. Hold them
side by side under daylight and they may look alike but move the pair
under tungsten or poor fluorescent light and the dye print will look red
while the silver print is always the same neutral tone. That's because
the silver molecules actually trap the light instead of depending on the
reflectance properties of dyes.
----- Original Message -----
From: "Marco Ugolini" <email@hidden>
To: "Ben Goren" <email@hidden>
Cc: "ColorSync Users Mailing List" <email@hidden>
Sent: Sunday, June 13, 2010 12:29 AM
Subject: Re: Good demonstration of metamerism?
In a message dated 6/12/10 2:29 PM, Ben Goren wrote:
I'd like to have a good demonstration of metamerism. At the least,
I'd like a
pair of side-by-side color patches that look the same under sunlight
but
radically different under fluorescent light. A pocket-sized target
with
several different such patches would be ideal.
I don't think there exists an inexpensive off-the-shelf item that
meets that
description, but I don't mind creating one.
So...can anybody offer any suggestions as to where to find items
(especially
paint chips) that can be easily matched by an inkjet under daylight
but that
fail miserably under other lighting conditions? If you have personal
experience of a match that gave you lots of trouble, I'd especially
like to
hear about it.
I'm aware of those ``check the light quality'' targets that are out
there.
That's the basic idea of what I'm looking for, but I'm more looking
for a
general demonstration and educational tool.
Thanks,
b& _______________________________________________
Just to make sure: you already know that when TWO specimens viewed by
an
individual with normal color vision under ONE same light source match
one
another, that is called a "metameric match", and when they don't it's
called
an instance of "metameric failure" -- correct?
In other words, "metamerism" does not indicate the DIFFERENCE between
the
two specimens: it indicates their similarity under a specific light
source.
In other words, it's a POSITIVE phenomenon, without which the only
possible
way to attain a color match would be to use exactly the same materials
as
the original (including the pigments).
People often use the word "metamerism" to indicate visual phenomena
that are
more appropriately referred to otherwise (namely, color inconstancy),
thus
conferring to the term "metamerism" an inappropriate NEGATIVE quality,
besides using it within an incorrect context.
I'm just trying to make sure that one starts off with a clear idea of
the
meaning of the terms. If the terms were already clear, then please
forgive
the intrusion.
Best regards.
Marco Ugolini
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