[argyllcms] Re: Using an i1 to measure FWA content?
- From: Martin Weberg <martin.weberg@xxxxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Sun, 7 Feb 2010 20:29:22 +0100
Hi
2010/2/3 Graeme Gill <graeme@xxxxxxxxxxxxx>:
> Another way is to compare the normal and FWA compensated readings
> with a UV free illuminant. So:
>
> spotread -S -i D50_0.0.sp
> Of course the best way is to use a spectrolino and compare the actual
> UV vs. non-UV plots.
For the fun of it I brought out my spectrolino and a few paper
samples. Used three measurement modes: no filter (-s -fn), no filter +
FWA D50 no UV (-s -fn -iD50_0.0.sp) and UV-filter (-s -fu). Mean of
three samples (n=3), standard deviations negligible. Ahh and argyll
1.0.3, since thats whats on my xubuntu machine right now.
See attached pdf's for spectral plots.
Paper 1
95.5 0.6 -2.1 / no filter
95.5 -0.1 0.1 / no filter + FWA D50 no UV
95.5 -0.8 3.3 / UV filter
Paper 2
95.9 1.2 -6.9 / no filter
95.8 -0.2 -2.9 / no filter + FWA D50 no UV
96.0 -0.5 -1.5 / UV filter
Paper 3
96.4 1.0 0.8 / no filter
96.3 0.9 1.2 / no filter + FWA D50 no UV
96.5 0.6 2.1 / UV filter
Paper 4
95.4 1.9 -6.1 / no filter
95.3 0.5 -1.9 / no filter + FWA D50 no UV
95.4 0.1 0.3 / UV filter
Paper 5
96.6 1.3 -0.4 / no filter
96.6 0.7 1.4 / no filter + FWA D50 no UV
96.8 0.3 3.1 / UV filter
Paper 6
93.7 2.7 -8.3 / no filter
93.6 1.1 -3.8 / no filter + FWA D50 no UV
93.8 1.1 -3.2 / UV filter
The FWA compensation using D50_0.0.sp lies approximately between the
no filter and UV filter readings for paper 1, 3 and 5. Paper 2, 4 and
6 are closer to the UV filter reading.
UV filtered readings having higher response below ~420nm. How is that?
Martin Weberg
Other related posts:
