White/blue lights

["Stella Chia" <stelc@xxxxxxxxxxxxxxxxxxxx>]

Hi All

In the midst of all the discussion on the white/blue type lighting, I would
like to draw your attention to this very informative site:
http://lighting.mbz.org/tech/info/blue_bulbs/

I don't want to be a wet blanket but seek only to "enlighten" (ok, ok,
sorry).  The author
has some very strong arguments against these lights.  Some "highlights"...
(sorry again)

Quote:
ARE BLUE HEADLAMP BULBS DANGEROUS?
Yes, they are. Here are the nuts and bolts of why blue bulbs are a bad idea:
The output spectrum of halogen headlamp bulbs includes *very* little light
in the blue frequency range. These blue bulbs have a filter coating on them
that allows only the blue frequencies through the filter. Because very
little light is produced by a halogen bulb in this range in the first place,
it is only this very small amount--a tiny fraction of the total amount of
light produced by a halogen bulb filament--that ever reaches the road. This
can be confirmed this with a good-quality non-chromosensitive light meter;
even a very apparently-bright blue bulb actually throws very little light.
(snip)
Blue is the shortest wavelength/highest frequency color of visible light,
and, as such, scatters the most readily. This is why the sky is blue rather
than any other color from the sun's white output spectrum.
And, you may find it interesting to find a dark blue storefront sign or
something else that's a dark, pure blue against a dark background in the
absence of white light. From any appreciable distance, it's almost
impossible for your eyes to see the blue lighted object as a sharply defined
form...the edges blur significantly.)
(End quote)

Check out the web pages as there's lots more lighting info.

The gummint just changed the street lights outside my house from the older
white type (mercury discharge?) to the yellow types.  The general area seems
to light up much better with less glare.  I'm quite convinced on the theory
part.

Andrew C
1300 GTj with one pair 100W Bosch Touring driving lights with yellow lenses

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