[Radiance-general] Illuminance and coloured lights

[Greg Ward]

Hi Lucio,

The lamp color data also includes depreciation factors, which  
probably account for the 10% difference.  I assume the "white" value  
is larger.

A long-standing bug has been recently pointed out by Zack Rogers  
related to the orientation of full photometric distributions, and has  
been included in the latest HEAD available from radiance-online.org.   
A statement has also been added to clarify the assignment of the  
width (along y) and length (along x) axes.

Hope this helps.
-Greg

> From: "loscotec\@libero\.it" <loscotec at libero.it>
> Date: February 6, 2008 6:28:49 AM PST
>
> Hi everybody !
>
> I've got a problem I'm not sure how to deal with.
>
> I'm using a Disano light to simulate a tunnel lighting. It is a  
> fluorescent light.
>
> I converted it to radiance format from ies format (previously  
> translated from eulumdat format) using ies2rad with no specific  
> value. Then I calculated illuminance on road surface visualizing  
> isolux scheme.
>
> Then I converted the same light with the "-t white" option. And  
> calculated illuminance's isolux as before.
>
> The two isolux schemes are different, being value for the white  
> case almost 10 % bigger.
>
> Shouldn't them be equal?
>
> I tried simulating same case in dialux and calculux, and they do  
> report  almost same values as the white case.
>
> What's wrong? Am I missing some knowledge / trick / anything?
>
> Lucio
>
> Ps : I also discovered some problems both in ies2tab and in  
> eulumcnv. The second, badly converting photometry (some dark  
> circles appear in the lighted scene as missing photometric values),  
> the first badly converting geometry (flipping x and y definitions).  
> But I have to check this things a little more.