Date:         Mon, 10 Aug 1998 12:03:32 +0200
Reply-To:     "Dr. Rainer Woitok" <woitok@RRZE.UNI-ERLANGEN.DE>
Sender:       Vanagon Mailing List <Vanagon@vanagon.com>
From:         "Dr. Rainer Woitok" <woitok@RRZE.UNI-ERLANGEN.DE>
Organization: RRZE (Regionales Rechenzentrum Erlangen)
Subject:      Re: Driving/Fog Lights
Comments: To: David Marshall <vanagon@VOLKSWAGEN.ORG>
Comments: cc: Vanagon@VANAGON.COM
In-Reply-To:  Msg <3.0.3.32.19980806175925.00d7d644@mail.abccom.bc.ca> of 1998-
              8- 6 17:59:25 -0700 from vanagon@VOLKSWAGEN.ORG
Content-Type: text/plain; charset=us-ascii

Hi all,

On Thu, 1998-08-06 17:59:25 -0700, David Marshall wrote:

> ...
> If you want to see in the fog, then yellow yellow/blue light is what you
> want.

That's not correct.  It's  true that fog tends to  absorb less  light in
the yellow  range  and more  in the  red  and blue ranges.   But there's
absolutely no  need  to emit yellow  light  in the first  place.  Yellow
tinted glasses will  absorb ligt of any color,   some colors more,  some
less, but they will  also absorb _yellow_  light.  The light produced by
the bulb is more or less white, that is it's a mixture of light with any
wavelength (or any color).  Thus use clear glasses to send as much light
as  your bulb produces into the  fog and let the fog  filter out the red
and blue  colors and mainly allow the  yellow part of your emitted light
come back to you.

What mainly makes foglights foglights is the special construction of the
lens and the fact that they are mounted relatively low above the ground.

Sincerely
 Rainer

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| Rainer M Woitok                  | Phone: (+49-9131) 85-7811, -7031  |
| Regionales Rechenzentrum         |                                   |
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