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From: debray@sbcs.UUCP (Saumya Debray)
Newsgroups: net.auto
Subject: Re: Color of the lights
Message-ID: <114@sbcs.UUCP>
Date: Fri, 2-Nov-84 15:31:50 EST
Article-I.D.: sbcs.114
Posted: Fri Nov  2 15:31:50 1984
Date-Received: Sat, 3-Nov-84 22:43:08 EST
References: <372@houxb.UUCP>
Organization: SUNY/Stony Brook CS, Stony Brook, NY 11794
Lines: 24

> Theoretically it is true that yellow is less absorbed by water vapor.
> However, the light loss due to the yellow filter is far greater
> than the small advantage the yellow provides. The net result
> is that you still see better with white fog lights.

Curious.  I had the impression that the principal reason for using yellow
fog lights is that the longer wavelengths (yellow, orange) are _scattered_
to a much smaller extent by water droplets suspended in air (which is what
fog is), which in turn means that they tend not to be reflected back into
the driver's eyes as much, and blind him with the glare.

The problem with white fog lights is that precisely because shorter
wavelengths are scattered to a greater extent by suspended particles, the
beam won't penetrate fog as well as that from a yellow fog light.  Granted,
you'll see the fog better with white lights, but I'd assume that's not what
you'd really want to see.
-- 
Saumya Debray, 	SUNY at Stony Brook

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