[Radiance-general] mgfilt, degree Kelvin into spectral data

[Gregory J. Ward]

Hi Christian,

The normalization of the spectral power distribution is unimportant,  
but I believe mgfilt outputs something that sums to 1.0 when  
integrated with the photopic curve.  Whatever it comes out to, the  
actual value is normalized by the reflectance or emission it's  
applied to.  Since you aren't applying it to anything, it doesn't  
matter.

Spectral power per wavelength can be any non-negative value (0 to  
infinity).  See also the previous thread entitled "specifying sources".

-Greg

> From: Christian Fusenig <christian_fusenig at gmx.de>
> Date: April 4, 2006 3:36:10 AM PDT
> ...
> Another question @all:
> I use "mgfilt" for conversions of  degree Kelvin into  spectral data.
> e.g.
> mgfilt c,cspec
> cct 2750
> cspec 380 780 0.0673 0.0841 0.1038 0.1262 0.1516 0.1801 0.2116  
> 0.2463 0.2841 0.3251 0.3689 0.4157 0.4653 0.5173 0.5719 0.6286  
> 0.6873 0.7479 0.8100 0.8734 0.9379 1.0035 1.0695 1.1362 1.2028  
> 1.2695 1.3359 1.4022 1.4675 1.5322 1.5961 1.6589 1.7206 1.7808  
> 1.8396 1.8968 1.9525 2.0064 2.0584 2.1089 2.1572
>
> How can it be that there are values above 1?  Can there be more  
> than 100%  "emission" at a certain  wavelength interval?
> I didn't find any documentation on the mgfilt programm, is there one?
>
> Thanks again,
>
> Christian