[Prev][Next][Index][Thread]

Re: (meteorobs) Re: Filters and visual response... [was Re: Arietids]

Hello friends,
 
I am doing tests with several filters and my webcam to look at the sky differently. I went on www.google.com and search. Hereunder is a link of some interest for both of you.
 
http://www.sdaa.org/SDAABulletins/Seeing.htm
 
Best regards from Belgium,
 
John
ON4EU
----- Original Message -----
From: Matthew Collier/cis/evp/Okstate
To: meteorobs@atmob.org
Sent: Friday, June 07, 2002 6:18 PM
Subject: (meteorobs) Re: Filters and visual response... [was Re: Arietids]


Okay,

I checked Minnaert's book.  No table or graph was provided of the polarization vs. angular distance from the sun.  However, Hecht's book on optics noted that skylight was "strongly" polarized 90 degrees from the sun.  The light is not completely polarized due to the depolarizing effects of multiple scattering events, and molecular anisotropies.  This makes sense.  I have used a polarizer to get photographic effects many times and the light from the sky is not completely blocked, rather a deep cobalt blue effect is produced.

Would a polarizer be useful?  Qualitatively, the polarizer would have to drop the effective limiting magnitude by at least the same amount as it diminuates the meteor magnitudes (assumed to be ~1 in my previous letter).

Matthew
Cushing, OK, USA
References: