UV-filtered Spectrocam
UV-filtered Spectrocam
- Subject: UV-filtered Spectrocam
- From: Roberto Michelena <email@hidden>
- Date: Fri, 30 Nov 2001 11:40:23 -0500
I am curious about this one...
A long time ago, there were lenghty discussions about whether more uv or
less uv was needed in a spectro's light source. I remember what I think were
the most significant points made:
- that the light source in most devices (ie SpectroLino) had actually less
UV content than natural daylight.
- that most devices were unable to cope with the "over 100%" reflectances
given back by fluorescent materials when excited by UV.
- Chris Cox: the SpectroCam (the original one) is the only device that
worked for inks that had some fluorescence.
- Bruce Fraser: better results obtained through the use of D65 filter in
SpectroLino. D65 better match to daylight.
- Many others reported good results with SpectroLino's uv filter when
dealing with fluorescent papers.
Etc. etc.; mostly what I made out of it was that SpectroLino had some
shortcomings in over-100 reflectance, and then it was better to cut out UV
in order to avoid those. But that in fact, the best would be more UV and
true D65 as the SpectroCam had, provided the device handled the over-100
reflectance correctly as the SpectroCam seemed to do.
So then, a uv-filtered SpectroCam would seem nonsense...
-- Roberto Michelena
EOS S.A.
Lima, Peru