-----Original Message-----
From: don spence <dkspence@telus.net>
...lens design. A proper lens will focus the light on the roadway ahead
with a top cut off that leans up on the right to illuminate road side
signs while not blinding oncoming traffic. The dispersal pattern should
light the road both near and far. Have a close look at some of the
modern lighting units. Very complex reflector and lens patterns moulded
into the unit. Also equals big bucks should you break one!
==AM==
Yet many of these modern lighting units, er, suck eggs. ;-) They're
getting better, but some of the early ones (mid-1980s, when they first
became legal on US-spec cars, and even some in the mid-1990s) were
pitiful when new AND deteriorated quickly.
I can't agree more about good lenses with sharp lighting focus and
cutoff patterns. Aside from PL700s, the first cool pair of
non-sealed-beam headlamps I ever had were Cibies -- "Optiques" I think
they were called. Anyway, slightly concave lens with a nice pattern
that allowed for just what you describe: a sharp cutoff of the light so
as not to blind oncoming drivers with the low beam, yet a wonderful
pattern to illuminate the side of the road. These, like the Lucas
PL700s, took what used to be referred to as the "Type A" bulb, so (with
the built-in three-prong plug on the bulb) they were easy to fit to a
car.
Neither the Lucas PL700 or earlier P700 had quite so sharp a cutoff,
but I still say they were better than a typical sealed-beam headlamp of
the era, all else being equal (comparing new units, that is).
--Andy Mace
*Mrs Irrelevant: Oh, is it a jet?
*Man: Well, no ... It's not so much of a jet, it's more your, er,
Triumph Herald engine with wings.
-- Cut-price Airlines Sketch, Monty Python's Flying Circus (22)
Check out the North American Triumph Sports 6 (Vitesse 6) and Triumph
Herald Database at its new URL: <http://triumph-herald.us>
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