"Terry Coombs" wrote in message
...
"anorton" wrote in message
m...
"Terry Coombs" wrote in message
news
"Steve B" wrote in message
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Are there any regulations on these new brilliant blue car headlights?
They are obnoxious, distracting, and in some cases, they blind me. I
do not know if they are after market, or standard equipment, but is
there anything being said or done about them? I have never ridden or
driven a car with them. What's the big deal, or improvement over
regular light spectrum headlights?
They are about as obnoxious as people who drive with their four
headlights on, the mains on low, and the fog lights on, with 75 mile
visibility. Those are as bright as high beams on most cars, and totally
unnecessary. I have turned mine on about ten times since I bought my
Dodge 2500 Ram new in '06. What is the need for all that light other
than "OOOOO LOOK AT ME!"?
Steve
There was a lot of discussion of those blue lights a few years ago on
the motorcycle forums . The reason they blind you is because the blue
light doesn't cause your iris to contract . Nasty little pieces of crap
and I hate 'em - they are illegal in many states .
As far as the bright lights ... I run a pair of aircraft landing lights
as side lamps on my bike along with an e-code headlight lens . On
brights with passing lamps on I project a fan of light about 25deg wide
out to about 400-500 yards . I can see the deer long before I get there
, which is very important up here in the Ozarks . I see an awful lot of
badly mis-adjusted lights ... and did my best to am mine properly . I
get maybe 1 car in 30 or 40 that will flick their brights on me while
on low beams/side lights .
--
Snag
I think the bit about blue light not causing your iris to contract is
only partially correct and is not the main issue. As an optical engineer,
I can point to three other issues that make these HID lamps annoying
1) The head lights do have more intensity, meaning more energy per
emitted angle, and that is the whole point.
2) There are regulations on maximum intensity, but the problem is (as I
understand it) there are no regulations on maximum brightness which is
intensity per unit area of the source. The arc of an HID lamp is smaller
than the filament of the equivalent halogen bulb, so even after the
reflector, the HID lamp source will appear smaller to your eye than the
halogen lamp. This means all the light that enters your pupil is focused
to a smaller spot on your retina. This is why lasers are annoying at low
powers and dangerous at moderate power. It seems regulations have not
caught up with the technology. It is quite possible to make a reflector
that reduces the brightness while keeping the same intensity.
3) The blue light scatters much more from dirt on your windshield as well
as defects in your eye, and in that way it adds to glare.
It is true that your eye is not as sensitive to blue as it is to the
middle of the spectrum. The pupil only responds to what it can see, so
given the same energy in blue and green, the blue will seem less intense
and the pupil will close less for the blue. Thus more undetected energy
gets through to your retina in the blue. However this does not cause any
annoyance or problem until the energy reaches the threshold where is
starts to cause damage. You can look at bright UV and not really know it.
In fact you can have a blind spot burned in your retina by a UV laser and
not realize it until later.
Was Steve talking about HID's or was he talking about those blue bulbs
they sell that "mimic" HID's ? I was thinking the latter when I responded
.
--
Snag
I have not heard about bulbs designed to mimic HIDs. I guess I am not
surprised if the goal is to make a cheap headlight look like an expensive
one. Certainly the true HIDs are very annoying.