Why the blue lights?

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Oct 2, 2004
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Okay, I know as an old fart, I'm probably a bit behind on the latest craze, but I'm wondering. What are the blue headlights I'm seeing on some of the oncoming cars at night these days?

Is there an advantage in visibility?

Curious about it.

Carl.
 
I believe there is a difference in visibility.

They don't make them more blue on purpose. Basically it is a different kind of light bulb and it just naturally produces slightly bluer light. Conventional incandescent light bulbs are pretty yellow to start with.
 
Yes, they are Xenon lights. The blue ones are usually a bit more of a cool factor thing, but the whiter ones are the brighter lights. The color depends on the temperature they burn at, as they are all really the same just with different ballast to burn the bulbs at different temps. They even have green, yellow, and purple. Plus, they last longer than traditional bulbs. High end cars come from the factory with Xenon projector beams, but you can buy a kit to upgrade any car for around $100, which sounds like a lot, but like I said the bulbs last a lot longer and if you go with white your visibility will be greatly improved.
 
I have an Acura with the "blue" lights and can notice a difference with rental cars. Mine are brighter.

Seems like some Hondas and BMWs use Xenon, too.
 
Yes, they are Xenon lights. The blue ones are usually a bit more of a cool factor thing, but the whiter ones are the brighter lights. The color depends on the temperature they burn at, as they are all really the same just with different ballast to burn the bulbs at different temps. They even have green, yellow, and purple. Plus, they last longer than traditional bulbs. High end cars come from the factory with Xenon projector beams, but you can buy a kit to upgrade any car for around $100, which sounds like a lot, but like I said the bulbs last a lot longer and if you go with white your visibility will be greatly improved.

You can actually pick up a kit for about $40 online. They are mostly made by the same company out of china. The bluer the light the less output, and once they turn a purple color you should just be kicked in the head for putting them in your car. They are based on the kelvin scale. Starting at 3000k - which is a yellow color mostly for fog lights. The next step is the 4200k to 6000k which have the highest overall light output, mostly a bright white to a light blueish tint, and then there is the dumb spectrum, 8000k to 12000k. Here you drastically lose light output and the light varies from a deep blue to a deep purple.
 
I hate halogens. Blinding. What's worse is how many people drive through town with high beams up, compounding the misery.

Police have added blue to their bubble gum machines for a while now. Blue has more of a tendency to diminish your night vision, it's a real bright attention-getter. It is opposite night vision red on the spectrum. I have an Inova X5 blue LED. It fluoresces some colors, like UV does.
 
I used to have the blue ones in my truck's headlights (came that way). Cars coming in the opposite direction used to flash their lights because they always thought my high beam was on.

One of them died a few weeks ago and was replaced with a normal yellowish bulb. Big difference in light output, but atleast people aren't blinded by me anymore.
 
The xenon/krypton HID bulbs tend to have a blue tint. It has more to do with the wavelengths produced at higher filament temperatures then style.

I've got the same problem with people driving around urban areas with high beams. No disrespect to my elders, but these people are almost always past retirement age. I suspect that they are night-blind and are trying to compensate. Unfortunately, at 50,000 candela everybody else gets dazzeled and are effectively night-blind!

Ironically, the cheapest way to get the most out of your headlights is to buy a $10 headlight restoration kit and polish the cloudiness out of the glass.
 
I'm past retirement age myself. :D In our town, glare is everywhere. It's not like my old neighborhood in NYC, but still walking down the streets late at night, the streetlights alone are bright enough to read a book by. High beams are a pain.
 
The HID's are bright, but as for actually driving with them, I honestly believe Halogens are better.
Halogens are definitely better for preserving night vision (that's why stargazers and dark room photo developers use red lights)
The wavelength of Halogens is much closer to red than the HID's.
Also, it's a proven fact that Halogens cut through mist, fog, and rain better than HID's.
That's why yellow is the preferred color for true fog lights.
True, most HID's are brighter than Halogens, but brightness alone does not a good headlight make.
Lenny
 
I have an issue with night driving, it gives me a pounding headache after about 1/2 hour. The HID/Xenon bulbs have made it worse, but I noticed in France that it took much longer for the headache/migraine to develop (about 3 hours). I attributed this to the yellow headlights most of them still drive on. As you can't get the English to drive with yellow lights, I've taken to driving with yellow glasses (the very pale "shooting" yellow). It has stopped the headaches completely and the visibility through rain and fog is unreal. You can see what's happening on the road all the time in the wet, rather than just after the wiper blade has swept.
 
Lenny you have it backwards, but you are correct on the big point. Yellow light cuts through mist and fog better than blue- for the same reason that the sky is blue. The amount of diffraction of light is inversely proportional to the 4th power of the wavelength. In other words, light with shorter wavelengths (blue end of visible spectrum) is diffracted (knocked off course/scattered) more than light of longer wavelengths (red end of visible). Halogens are preferred for fog lights because they are yellow, not the other way around.

Incidentally, sun sets are red because the light is traveling through more air/particulates and the longer wavelengths of light are diffracted.

I read somewhere that red wavelengths are no better than any other color for night vision preservation, given an equivalent amount of light output. Red lights are better only because they are much dimmer than yellow or white lights.
 
On the subject of destroying night vision, a strobe light has a much more persistent effect than the plain light on its own. Night vision seems to take about 3 times longer to recover.
 
The ones I saw last night were VERY blue . That has to be stressful to the eyes.The eyes really want full spectrum light like sunlight. BTW for those who are very sensitive to bright lights and glare may be suffering from a vitamin A deficiency!!
 
I have an issue with night driving, it gives me a pounding headache after about 1/2 hour. The HID/Xenon bulbs have made it worse, but I noticed in France that it took much longer for the headache/migraine to develop (about 3 hours). I attributed this to the yellow headlights most of them still drive on. As you can't get the English to drive with yellow lights, I've taken to driving with yellow glasses (the very pale "shooting" yellow). It has stopped the headaches completely and the visibility through rain and fog is unreal. You can see what's happening on the road all the time in the wet, rather than just after the wiper blade has swept.
I'm going to try this, thanks for the tip!
 
Personally, I can't stand the blue-tinted bulbs or the HID lights either. They just create one more distraction during night-time driving - and that reduces overall safety on the road. I think they should be banned, but I'm afraid that horse is outta the barn...

TedP
 
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