RE: IT8 Scanning Standards/Future of ICC
RE: IT8 Scanning Standards/Future of ICC
- Subject: RE: IT8 Scanning Standards/Future of ICC
- From: Jon Meyer <email@hidden>
- Date: Mon, 12 Feb 2001 07:19:24 -0500
I like to use ScanOpen for creating input profiles. With ScanOpen
Lite 2.1 (free with LinoColor Elite), or with ScanOpen 4, the Dmin
can be set to the base density in most scanner dialogues. Choosing a
correct value requires knowing the Dmin of the target you are using.
Remember, you might come across film which has a lower base plus fog
Dmin than that of the IT8.
Allowing a factor to compensate is critical. If optimum Ektachrome
Dmin is in the .10 to .12 range, and the IT8 is potentially a .14-.15
range, then pad your end point number so that you never hit 255s in
production scanning.
As each scanner interface is unique, the actual value to plug in for
the highlight will vary.
On a separate issue, the PMA photo trade show is being held in
Orlando Florida at the moment. One of Kodak's color scientists, Tom
Madden, discussed a new color paradigm.
In an ideal scanning scenario, the scanner would colorimetricly see
film or reflective material in the way the human eye perceives color.
The firmware of the scanner would more accurately describe that
sensitivity. This is the characterization of the device.
A table location for creating a calibration of the specific serial
number-related differences would also reside with the scanner. In
other words, most correction is in the scanner firmware and a mild
correction for assembly-line issues would be in the secondary table.
An ICC profile would be available to further adjust for a specific
set of dyes or characteristics of a photograph. The target data
reference file must be created at the white point of the scanner's
lightsource.
The proposed paradigm helps to narrow the differences we are seeing
today between Ektachrome/Fujichrome/Agfachrome emulsions. It also
better accounts for capture of reflective photographs, fine art or
other materials.
Tom carried the same concept into the output side, suggesting that
devices would become better behaved in their characterization,
calibration and profiling. The result is that gear (kit for your
Brits), would evolve which produces images based more on colorimetry
and the human visual response, than on old technology.
- Jon
should I read the dmin white patch on the Kodak Q60 used for profiling the
scanner, and use that value as my "absolute" base density in the bd setup
dialog? I have it at 0.05 right now, w/relative set to the same value, which
is what I read off the dmin patch w/my densitometer. the docs say something
about setting these two to the same value for reflectives but it's not very
clear to me. I don't use the automatic BD analysis function as this is a
gang-scanning situation.
*******************************************************
Jon Meyer
GrafixGear
email@hidden
http://www.GrafixGear.com
8 West Glen Avenue
Ridgewood, NJ 07450
USA
(201) 447-1510 voice
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