Re: Optical Brightneners
Re: Optical Brightneners
- Subject: Re: Optical Brightneners
- From: Steve Upton <email@hidden>
- Date: Wed, 19 Dec 2001 09:57:16 -0800
At 12:01 PM -0500 12/19/01, Roger Breton wrote:
I am getting a greenish cast on my simulation from a Matchprint profile to a
Canon CLC printer out of a CMYK image in Photoshop (ConvertToProfile from
Matchprint to Canon - any Intent or CMM). Before getting into editing the
Canon profile, I tought I would measure the color of the paper (inexpensive
office-type Bond paper 20 lbs).
Here is what the Spectral Data looks like (from ColorShop). This is measured
with an X-Rite Digital Swatchbook - no UV filter, obviously). Is it possible
to conclude unequivocally on the presence of OB from this data ? Notice the
bump at 430nm and 440nm. (Appologize in advance for the unusually long
length of this message)
This bump is pretty much the best indicator of fluorescence. The -b
value is inconclusive as, of course, the paper could be a little blue
and -3 could be enough where you might not notice it much in certain
lighting. The bump is pretty tell-tale.
That does not mean that the software will react poorly though, that
seems to depend on some mysterious internal factors... It seems to be
bugging you though. A UV light is a great tester for this as you can
quickly see the glow.
Regards,
Steve Upton
________________________________________________________________________
o Steve Upton CHROMiX www.chromix.com
o (hueman) 866.CHROMiX
o email@hidden 206.985.6837
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