Re: Technical history of Radius ColorMatch
Re: Technical history of Radius ColorMatch
- Subject: Re: Technical history of Radius ColorMatch
- From: email@hidden (Bruce Fraser)
- Date: Sun, 8 Apr 2001 10:24:27 -0700
At 3:12 PM +0200 4/8/01, Henrik Holmegaard wrote:
I'm trying to get a grip on the technical history of the old Radius
'ColorMatch' concept.
Was the original Radius idea along the lines of an 'RGB PCS' which
physical monitors could then be brought up to using calibration, and
then from that 'RGB PCS' you had separation tables you could plug
into Pshop?
What interests me is the relationship between the actual state of
the monitor and the values used as input in the RGB to CMYK
conversion.
a. Were the values the same as what the monitor was brought up to,
meaning that ColorMatch was actually a different space on each
workstation, and each workstation therefore gave you a different
CMYK, even if the CMYK table was the same on all workstations, or
b. Were the values the same as a fixed RGB which the monitor would
then approximate as well as possible, but you got the same input
values for all workstations, and if all workstations chose the same
destination, then you got the same CMYK off all nodes in the color
network ?
I know Roger was Radius product manager back then, so I've cc:ed
him, if nobody else knows.
Thanks in advance
--
Henrik Holmegaard
TechWrite, Denmark
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ColorMatch RGB defined both a reference working space and an
achievable aim point for monitor calibration for the Pressview
series. So b rather than a. Most Pressviews I used met the spec
pretty closely -- the main weakness was the black level, which the
Pressview sensor wasn't really sensitive enough to set reliably.
Remember that thisgoes back to the days before RGB working spaces,
when RGB was always monitor RGB. The goal was to ensure that all
Pressviews behaved identically, so that the Colormatch RGB spec could
be used as both the monitor description and as an unambiguous RGB
working space.
I have the Radius white papers somewhere if you want them -- one on
ColorMatch Reference RGB, one on Viewing Conditions.
Bruce
--
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