Re: colorsync-users digest, Vol 2 #645 - 16 msgs
Re: colorsync-users digest, Vol 2 #645 - 16 msgs
- Subject: Re: colorsync-users digest, Vol 2 #645 - 16 msgs
- From: "Michael S. Dodds" <email@hidden>
- Date: Tue, 27 Nov 2001 11:46:08 +0000
on 11/27/01 6:01 AM, email@hidden at
email@hidden wrote:
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Message: 1
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From: email@hidden
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Date: Mon, 26 Nov 2001 03:44:07 EST
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Subject: Reply to Myers RE: Vision Range
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To: email@hidden
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According to a Xerox/Tektronics training CD on Color Theory
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"If you have normal color vision, you can detect about 150 steps within the
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visible spectrum, from violet to red. Factoring in possible changes in
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brightness and saturation, color scientist calculate that you can
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discriminate over 7 million different colors. So why do Tektronix color
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printers generate a palette of 16.7 million shades? Is the excess color
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wasted? The answer of course is 'no.' The enormous number of colors allows
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the smooth shading of one color into another, which in turn fosters the
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lifelike realism possible with high-end color printers."
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There are no references offered on the CD, and I assume that they refer to
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Xerox Color Scientists... and if it weren't for Steve's visit to Xerox PARC
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years ago, we might not be having a ColorSync discussion... So, I would
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believe these Xerox guys.
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So - now there are some numbers to work with.
If a photospectrophotometer is in a bright room and measures a swatch
it would read the same numbers for that swatch in a dark room.
Is that correct? - because the color IS the same whereever it is.
Now -
If a human views these two situations -
we would perceive the same swatch as "different" colors,
because of the brightness factor.
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So if you say we "see 7 million" colors
and 150 levels of colors.
Then are you pushing the number of perceivable colors
to over one billion colors?
How have the color scientists "factor" in
brightness and saturation?
Maybe this is something we don't need to know.
It just seems like - if we are preparing files and equipment
to print things which people will hopefully view,
we might as well know what they CAN see.
MSD