[argyllcms] Re: spotread filters

  • From: Gerhard Fuernkranz <nospam456@xxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Fri, 06 Jun 2008 18:28:17 +0200

Jacques Warnon wrote:
> Our printing media (sublimated polyester) seems to wreak havoc on 
> colorimeters, especially in the highlights. It seems similar to the effect of 
> optical brightening agents, but much more pronounced.

Jacques,

if it is a fluorescence issue, then I would expect that a profile made
from measurements with the i1 (no uv-filter) should be at least fine for
viewing the print under a tungsten light source (since the i1 uses a
tungsten lamp too). Is this the case? Do your prints generally change
the perceived color significantly under different kinds of light sources?

And if it is an UV-induced fluorescence issue, then I'd expect to see a
clarly noticeable difference when comparing the shapes of the
reflectance spectra of the substrate captured with the i1 with and w/o
UV filter. But of course fluorescence does not need to be necessarily
induced by UV, but can be also induced by any other wavelengths too
[only FWAs are designed in particular to turn UV into visible light].

Btw, what exactly is the impact you are observing? How do you judge w/o
any "good" reference measurements that your measurements are "bad"?

Regards,
Gerhard


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