[Radiance-general] diffuse + specular > total reflectance?

[Jack de Valpine]

Hi Lars,

I think that what you want to do is:

    <total reflectance> - <diffuse reflectance> = <specular reflectance>

    thus

    86 - 10 = 76

The specular reflectance that is provided is for a measurement at 60 
degrees incidence, if I understand this correctly.

-Jack

Lars O. Grobe wrote:
> Hi,
>
> as this may be because of some standards that I am not aware of, I 
> have a question about a record of material properties that I do not 
> understand yet.
>
> I have a high reflective surface, and the manufacturer gives me these:
>
> reflectance specular   60 degree: 82
> reflectance diffuse:                        10
> reflectance total (ASTM E1651):   86
>
> If I add 82 and 10 I get 92 > 86 for the total reflectance. So what 
> does this mean, are the values related to the way the reflectance is 
> measured and calculated using different procedures according to 
> standards?
>
> CU Lars.
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-- 
# Jack de Valpine
# president
#
# visarc incorporated
# http://www.visarc.com
#
# channeling technology for superior design and construction

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