Re: driving/pencil/fog

[AUDIONLY@aol.com]

In a message dated 95-09-08 08:32:36 EDT, PDQSHIP@aol.com writes:

>Fog:  short range (low beam) wide angle horizontal, sharp cut vertical.....
> Used for low visibility conditions, rain/fog/dust/snow

In the Hella series model Rallye 2000 that has been mentioned, (Hella makes
17 different types of driving lamps in addition to the specialized lamps they
make for different automobile manufactures)  the fog lamp is 55W and a range
of 750 feet at 45 degrees from the direction of the light. You can get it in
either the white or amber lens.
>
>Driving:  long range (hi beam) narrow angle horizontal  narrow angle
>vertical......  Used to augment hi beam stock lighting

Again in the Hella series model Rallye 2000, the driving lamp has a wattage
of 55W with a range of 7000 feet (dimensions of fringe illumination, not high
intensity zone) Its projection is "test tube" shaped from the direction of
the light.

>
>Pencil Beam:  very long range (hi beam) extreme narrow horizontal extreme
>narrow vertical usually used in conjunction with Driving lites, considered a
>very "hot" highly reflective beam pattern with a very small "pencil of lite"
>at long range

Again in the Hella 2000 series, the wattage for the pencil beam is 100W and
its projected range is 18,270 feet!!!!!. (Again, this is fringe illumination,
not high intensity zone. The projection is flame shaped from the direction of
the light.

In addition to these, in the Hella 2000 series are the following:

Euro Beam Lamp:

It uses a 100 watt bulb and projects 13,300 feet in a "test tube" pattern.

Wide angle cornering Lamp:

It also uses a 100 watt bulb and projects 1000 feet at a 78 degree angle out
from the direction of the light.

And as far as cutoffs, find the following excerpts from the Hella Headlamp
Systems brochure:

The FF headlamp:

The Hella headlamp has a reflector which is not a paraboloid. Each point on
it is calculated by computer, hence its name "Free Form". The computer starts
with the light cistribution required and uses this to shape the 3-dimensional
reflector surface. This sounds easy and logical, but development and
production are complicated. A fract of a thousandth of a millimetre is the
order of accuracy required. (Sounds like the Hubble) Whereas with a
conventional paraboloid headlamp the lower half of the reflector remains
unused, the whole of the reflector is used with the Hella free form headlamp.
This means a theoretical increase in light output of 80% The light is placed
exactly where it is required. This means brighter more even illumination of
the road, greater range, negligible stray-light losses and glare. 

The DE headlamp:

The DE headlamp is an innovation from Hella. It functions rather like a slide
projector. The bulb is positioned at the focal point on the ellipsoid. A
shield is used instead of a slide to produce the cut-off. The convex lens
projects the light onto the road. This means more light output for better
vision, a sharper cut-off, minimum glare and more safety. Hella DE headlamps
are small but produce superior lighting performance.

--peter
Audionly