Here's some post I found off a newsgroup...he's basically saying sticking in some HIDs in regular headlights are bad...but read the last paragraph, he actually mentions projectors and Hellas! This gives a great "excuse" to get projectors!
Some guy was selling/promoting HIDs and this guy replied with the following:
**********
By Daniel Stern Lighting
Better yet, don't.
There are many unsafe, illegal and noncompliant products on the market,
mainly consisting of an HID ballast and bulb for "retrofitting" into a
halogen headlamp. Halogen headlamps and HID headlamps require very
different optics to produce a safe and effective -- not to mention legal
-- beam pattern. It is not some great feat of upgrade engineering to put
an HID capsule where a halogen bulb belongs, it is just plain foolishness.
Some types of halogen headlamp bulbs (9004, 9007, H3) use a transverse
(side-to-side) and/or offset (not directly in line with the central axis
of the headlamp reflector) filament, the position and orientation of which
is physically impossible to match with a "retrofit" HID capsule. Even
those halogen headlamps that use axial-filament (9005, 9006, H1, H7) bulbs
are not safely or legitimately "convertible", regardless of what kinds of
"clever" products the junk vendors come up with.
The most dangerous part of the attempt to "retrofit" Xenon headlamps is
that sometimes you get a deceptive and illusory "improvement" in the
performance of the headlamp. The performance of the headlamp is perceived
to be "better" because of the much higher level of foreground lighting (on
the road immediately in front of the car). However, examining isoscans of
the beam patterns produced by this kind of "conversion" reveals *less*
distance light, and often an alarming relative minimum where there's meant
to be a relative maximum in light intensity. When you *think* you can see
better than you can, you're *not* safe.
It's tricky to judge headlamp beam performance without a lot of knowledge,
a lot of training and a lot of special equipment, because subjective
perceptions are very misleading. Having a lot of strong light in the
foreground, that is on the road close to the car and out to the sides, is
very comforting and reliably produces a strong *impression* of "good
headlights". The problem is that not only is foreground lighting of
decidedly secondary importance when travelling much above 30 mph, but
having a very strong pool of light close to the car causes your pupils to
close down, *worsening* your distance vision...all the while giving you
this false sense of security. This is to say nothing of the massive
amounts of glare to other road users and backdazzle to you, the driver,
that results from these "retrofits".
HID headlamps also require careful weatherproofing and electrical
shielding because of the high voltages involved. These unsafe "retrofits"
make it physically possible to insert an HID bulb where a halogen bulb
belongs, but this practice is illegal and dangerous, regardless of claims
by these marketers that their systems are "beam pattern corrected" or the
fraudulent use of established brand names to try to trick you into
thinking the product is legitimate. In order to work correctly and safely,
HID headlamps must be designed from the start as HID headlamps.
The only safe and legitimate HID retrofit is one that replaces the
*entire* headlamp -- that is lens, reflector, bulb...the WHOLE shemozzle
-- with optics designed for HID usage. It IS possible to get clever with
available products, such as Hella's modular projectors available in HID or
halogen, and fabricate your own brackets and bezels. But just putting an
HID bulb where a halogen one belongs is bad news all around.
_________________
Henry
Visit my Camry Website!
<font size=-1>[ This Message was edited by: Silver Streak on 2002-03-10 23:17 ]</font>
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