Re: mired

[T3D George Gioumousis <georggms@xxxxxxxxxx>]

John Bercovitz wrote
> And now we see that what I observed before, that the same filter
> that would take you from 6000K to 4000K would also take you from
> 4000K to 3000K is also true in the mired system because the dif-
> fernce between 6000K and 4000K is 83 mireds and the same can be 
> said for the difference between 4000K and 3000K.  OK, so it works.
> Nice.  Have I become unmired now?  Possibly.

I guess I'm in the minority, since I find distribution functions
easier to follow than spreadsheets.

Of course, my memory sometimes gets a little fuzzy. In my earlier
post on this thread I said that Rayleigh scattering goes inversely
as the wavelength. After thinking about it, I lost my conviction,
so looked it up in a marvelous book by M. Minnaert, "The Nature
of Light and Color in the Open Air." It turns out the right variation
is inversely as lambda to the fourth power. The book says that 
the really dominant color in the sky is violet, but our eyes are
not very sensitive to it, so that's why it looks blue.

The section on why the sky looks blue starts with this paragraph:

   In unending beauty the blue sky spans the Earth. It is as
   if this blue were fathomless, as if its very depth were
   palpable. The variety of its tints is infinite; it changes
   from day to day, from one point of the sky to the other.

Neat for a book full of equations, isn't it.
-- 
George Gioumousis           /---\        |       /---\ 
                             o o         |       o o  
georggms@xxxxxxxxxx           |          |         |   
(415) 494-6276              \===/        |       \===/ 


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End of TECH3D Digest 22
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