Moonlight SPD?
TKM
but it's odd that it doesn't show up in the usual references on light and
color. I'd like to have both a curve and the relative data points.
Terry McGowan
Victor Roberts
wrote:
Well, there is a crude one here, along with directions for a
low cost spectrometer:
http://www.cs.cmu.edu/~zhuxj/astro/html/spectrometer.html
I bought an Ocean Optics spectrometer at the end of the
year. I'll have to see if it can pick up moon light,
perhaps with the aid of one of my telescopes - but may have
to wait until it gets a bit warmer outside :-)
--
Vic Roberts
http://www.RobertsResearchInc.com
http://www.cflfacts.com
sci.engr.lighting Rogues Gallery http://www.langmuir.org
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Victor Roberts
wrote:
>Anyone have an SPD of moonlight? I know it's quite like the solar spectrum;
here are some:
http://www.astrosurf.com/buil/us/spectro10/sky.gif
http://people.ucalgary.ca/~ccsunstr/images/GraphSpectraMoon.jpg
And here's a Google search page that has more spectra, and
perhaps more lunar spectra, but I haven't checked them all.
http://images.google.com.eg/images?hl=en&q=spectrum%20of%20moon&um=1&ie=UTF-8&sa=N&tab=wi
Don Klipstein
My experience suggests visible portion is essentially sunlight filtered
to approximate a blackbody of somewhat lower color temp., with color very
much like that of blackbody and CRI almost certainly 100 or maybe 99.
As for color temp: My experience says usually mid-upper 3,000's, often
around 3800. Closer to zenith with especially clear air, appears to
me about 4000, maybe 4100 in especially favorable conditions.
- Don Klipstein (d...@misty.com)
Don Klipstein
>On Sat, 2 Jan 2010 17:06:11 -0500, "TKM" <nom...@no.net>
>wrote:
>
>>Anyone have an SPD of moonlight? I know it's quite like the solar spectrum;
>>but it's odd that it doesn't show up in the usual references on light and
>>color. I'd like to have both a curve and the relative data points.
>>
>>Terry McGowan
>>
>
>here are some:
>
>http://www.astrosurf.com/buil/us/spectro10/sky.gif
To me, that does not compute - too similar to each other, both look to
me around upper 4,000's to maybe 5,000 K and a bit greenish, with moon
having close to same CCT as sky and slightly more greenish.
>http://people.ucalgary.ca/~ccsunstr/images/GraphSpectraMoon.jpg
I come up with about 3650-3700 K CCT for that one - though it deviates
from blackbody somewhat by having more orange and less deep red than 3700 K.
Looks reasonable - I would at this point expect longer wavelength
portion of SPD to have a curve shape closer to that of sunlight, maybe
like mid-upper 4,000's K.
>And here's a Google search page that has more spectra, and
>perhaps more lunar spectra, but I haven't checked them all.
>
>http://images.google.com.eg/images?hl=en&q=spectrum%20of%20moon&um=1&ie=
>UTF-8&sa=N&tab=wi
>
>--
>Vic Roberts
- Don Klipstein (d...@misty.com)