Re: I don't want my Spectrocam and Colourblind software anymore
Re: I don't want my Spectrocam and Colourblind software anymore
- Subject: Re: I don't want my Spectrocam and Colourblind software anymore
- From: Graeme Gill <email@hidden>
- Date: Tue, 25 Jun 2002 14:02:49 +1000
Marc Aguilera wrote:
>
It will be
>
welcome knowledge to get to the bottom of UV-filtration at Seybold as
>
well as determine some real world evaluations of color management
>
software.
Why wait for Seybold ? As far as I can tell, there is no sound
theoretical basis for imagining that turning on a UV cutoff
filter will magically fix profiles that are affected by
fluorescence (typically paper whitener).
The facts are that the instrument is measuring the samples
using one spectrum of light (usually an incandescent lamp, ie "A" curve,
sometimes a D65ish Xenon lamp) that trigger one level of fluorescent
response, and real world viewing conditions have a different spectrum,
triggering different amounts of fluorescence.
Adding a UV cutoff filter may give you a reflectance measurement for
that media without the presence of the fluorescent light contribution,
but the real world viewing conditions do trigger fluorescence,
and an accurate characterization of the media needs to model this.
[I have developed a method of modeling paper whitener fluorescence
that doesn't rely on having a bispetral instrument or a UV cutoff
filter. Preliminary results seem to indicate that it more accurately
models real world paper whitener effects, but I'm still playing around
with it.]
Graeme Gill.
_______________________________________________
colorsync-users mailing list | email@hidden
Help/Unsubscribe/Archives:
http://www.lists.apple.com/mailman/listinfo/colorsync-users
Do not post admin requests to the list. They will be ignored.