[Radiance-general] Spectrophotometer use and material reflectance

[iebele]

Hi John,

It is a long time ago that I experimented using a Minolta spectrometer, I 
think is was in 2000.
At that time I wrote and bundled some scripts and documents, I just put 
these on the server for you:
http://www.iebele.nl/radiance/callibrate/

Look in this document for "Minolta's spectro-photometer"
You will need these scipts/programs:

http://www.iebele.nl/radiance/callibrate/minolta.c ( just one of my own 
progs, ...)
http://www.iebele.nl/radiance/callibrate/spct2xyz
http://www.iebele.nl/radiance/callibrate/xyz2rgb


Because most of the page is written in Dutch, here a short help:
( spectraal-q14.txt  is a just a file from your spectrometer )

$ ./minolta < spectraal-q14.txt
 Convert Minolta photospectrometer spectral data list
 Ranging from 400 to 700 nm
 This data can be read by spct2xyz
 Number of steps in spetcrum  : 31
 Number of measured items     : 20
 Writing file Q14-0.spc 1
 Writing file Q14-1.spc 2
 ...
 Writing file Q14-19.spc 20

Now check the result:

$ more  Q14-0.spc
#nm      reflectance
400     0.728000
410     0.799700
...
700     0.933800

Now translate  *.spc files to .xyz and  .rgb line this:

$ ./spct2xyzQ14-0.spc >  Q14-0.xyz
$ ./xyz2rgb  < Q14-0.xyz >  Q14-0.rgb


I don't know if these scripts still work, or if they are accurate,
hope it helps you a little,

Iebele





----- Original Message ----- 
From: "John Mardaljevic" <jm at dmu.ac.uk>
To: <radiance-general at radiance-online.org>
Sent: Thursday, July 24, 2008 10:41 AM
Subject: [Radiance-general] Spectrophotometer use and material reflectance


> Anyone using a spectrophotometer to measure reflectances for use in 
> Radiance?  Section 5.1.9 (p304-307) of the Radiance book shows how it  can 
> be done.  Is this method still used, and if so could you post/ email the 
> scripts spct2xyz.csh and xyz2rgb.csh?
>
> Any tips/pointers not already covered in Section 5.1.9 would be much 
> appreciated.  We'll be using a Konica/Minolta CM-2600d portable 
> spectrophotometer.
>
> Cheers,
>
> -John
>
> -----------------------------------------------
> Dr. John Mardaljevic
> Senior Research Fellow
> Institute of Energy and Sustainable Development
> De Montfort University
> The Gateway
> Leicester
> LE1 9BH, UK
> +44 (0) 116 257 7972
> +44 (0) 116 257 7981 (fax)
>
> jm at dmu.ac.uk
> http://www.iesd.dmu.ac.uk/~jm
>
>
>
> _______________________________________________
> Radiance-general mailing list
> Radiance-general at radiance-online.org
> http://www.radiance-online.org/mailman/listinfo/radiance-general
>