Re: Spectral Response and Colorimeters....
Re: Spectral Response and Colorimeters....
- Subject: Re: Spectral Response and Colorimeters....
- From: "Michael S. Dodds" <email@hidden>
- Date: Sun, 03 Feb 2002 18:19:56 +0000
>
On the other hand, I have found that there is a lot of sloppy work in the
>
field as well. It makes no sense to profile a device that does not have an
>
associated solid quality assurance test. At the start of this whole mess, I
>
was very vocal about including a set of densitometric readings of known
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patches in the profile. My point was that these patches could be monitored
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using simple densitometric devices and we would then be assured that the
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profile we are using would be based upon known device parameters. If the
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simple measurements were off, we would know that the profile was no longer
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accurate. That sort of fell on deaf ears and now the average user has no
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standard mechanism to test the device to see if it has drifted relative to
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the profile....For some, it made more sense to go through the whole profile
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generation process another time, but we then we still have the constant
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uncertainty of machine performance vs. profile accuracy. In my opinion, the
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Color Mangement Providers have not provide the necessary quality assurance
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tools to allow the customer to use the process with any objective degree of
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certainty. That's a roadblock to success that should be addressed.
>
>
Tom Lianza
>
Technical Director
>
Sequel Imaging Inc.
>
25 Nashua Rd.
>
Londonderry, NH 03053
>
email@hidden
----
I think the printing process needs to keep its concerns
to some type of minimum. Getting 2 different press
operators to operate the same press in an exact manner
is next to impossible. You stick the Gretag Bars on there
and there is plenty for a good operator to consider.
Density - gain - slur - plate quality -- it is all there.
Many press guys use just the density chips. (unfortunate)
Watch a couple guys run a press -- One operator will
run his plates nice and dry and get good clean dots
and good solid density. The next fellow comes in at the beginning of the
next shift - and, soon, the plate is glistening wet with water
creating slur and emulsification of the inks.
BUT - the densities may be identical.
(Just keep piling on the ink).
-- The press profile is, no doubt, invalidated.
If the operators needed to be concerned adout
matching density of 280 different chips -
the would be very difficult people to be around, indeed.
-- Also,
With todays costs and "money saving" concerns -
there is no room on a job press sheet
for the IT8 chart.
Hell - I often have no room for color bars at all.
--
The standard Gretag color Bars can run a press.
--
We need to get our OLD and NEW presses
running as well and consistently as possible -
then feed them plates made with the
individual press characteristics being considered.
OH well !
MSD