Re: Optical Brighters while using UV Filter
Re: Optical Brighters while using UV Filter
- Subject: Re: Optical Brighters while using UV Filter
- From: Roger Breton <email@hidden>
- Date: Sun, 18 Jul 2004 10:09:32 -0400
>
Roger, is your ICCOLOR and/or Eye-One UV-Fitted?
My EyeOnePro is NOT UV-fitted. My ICColor is NOT UV-fitted. My DTP41usv IS
UV-fitted.
>
I thought that if the
>
DEVICE itself were UV-Fitted, then it (the device) would filter out any UV
>
Brighteners BEFORE the measurements even got to the software. Thus making
>
the UV check box in PM unnecessary.
That is true. If the measurements are UV-corrected then there is no need to
turn the Correction for Optical brighteners in PMP.
>
And for those that were NOT using a UV
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Filter, they had the option of correcting in software by using the check
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box.
Right.
>
As to your ending up with a cast, that is the reason why I would never buy a
>
N0N uv-fitted device.
Well, I have the exact opposite experience. And I have friends in the
prepress trade that have the same exact experience as mine: measuring with
UV included is superior to measuring UV excluded. If I had a way to
selectively weed out the influence of the UV excitation, maybe by using a
true spectrofluorimeter, then, possibly, I would end up with a real
measurement of the color devoid of any sort of OB content or fluorescence.
But I don't. I know some people on this list have found a way to use their
Spectroscan to measure once without UV filter on their Lino and once with
the UV filter on, and by taking off the UV influence in the measurement they
end up with better measurements for profiling. I don't have a Spectroscan to
try this method unfortunately and if I did, I would have to first understand
an analytical method to take the UV off -- maybe by subtracting spectras?
>
My Ideal situation would be to have one of each so
>
that when profiling a stock that definitely has no Brighteners, I can leave
>
the filter off (I see filter off like a Raw High-Bit Scan, <So to say>).
I have both kinds of instruments. And I can remember experimenting with a
regular DTP41 and a DTP41uv, and the results, invariably, in my experience,
has always been better, from a color matching point of view, WITHOUT the UV
filter in the way. But that's my experience. And, believe me, both
instruments were freshly calibrated. And this was on inkjet printers with
Epson mildly fluorescing paper (b=-5 type).
>
Having read past post about the issues (yellow cast) people were having
>
while profiling papers with Optical Brightners, I would rather use the
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UV-Fitted device.
I respect your opinion. Which instrument did you say you use?
>
At the very least and to my knowledge, only GM has that
>
switch. So, if you which to correct for optical Brightners in another
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software, it could help to have it.
PrintOpen also has such a switch. But Fuji ColourKit does not. Nor does
Monaco.
>
Cedric Briscoe
Roger Breton | Laval, Canada | email@hidden
http://pages.infinit.net/graxx
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