Dangerous, illegal, blue headlight bulbs

What's All The Fuss?


Various companies and individuals are selling halogen headlamp bulbs with blue or purplish-blue glass. There are lots of spurious claims made for these bulbs. They're falsely advertised as "Xenon bulbs" or "HID bulbs", the blue glass is claimed to "force the bulb to perform at a higher level", and there are seemingly endless amounts of pseudoscience aimed at enticing buyers who want better performance from their headlamps. In fact, these bulbs reduce headlamp performance while increasing dangerous glare.

How and why are blue bulbs dangerous?

Many of them degrade roadway safety,? both yours and other drivers'. Some of them can be physically hazardous. Here are the nuts and bolts of why blue bulbs are a bad idea:

White light is made up of every color of light mixed together. But the colors are not all present in equal amounts. The output spectrum of filament bulbs, including halogen headlamp bulbs, includes a great deal of red, orange, yellow and green light, but very little blue or violet light. Blue bulbs have colored glass (or a filter coating applied to clear glass) that allows only the blue light through the filter ? this is why the bulbs appear blue. Because very little blue light is produced by a halogen bulb in the first place, it is only this very small amount ? a tiny fraction of the total amount of light produced by a halogen bulb filament ? that ever reaches the road.

Blue and violet are the shortest wavelength/highest frequency colors of visible light, and, as such, they scatter the most readily. This is why the sky is blue rather than any other color from the sun's white output spectrum. Blue light doesn't just scatter most readily in the sky, but also in the eye. To observe this effect, try this informal experiment: Next time you see a dark blue storefront sign or a row of blue airport runway landing lights after dark, notice how blurry the edges of the sign or landing light appears compared to adjacent lights or signs of different colors. Decades ago, hot rodders would install "blue dots" in their cars' taillamps. These small bits of blue glass cause the taillamps to appear not red with a blue dot in the center, but rather pinkish-purple, because the observer's eye easily focuses on the red but has trouble with the blue, which remains out of focus and appears to tint the entire area of the red light.


How can there be more glare if there's less light?

Informal tests by the US Department of Transportation's Office of Crash Avoidance Standards found that a standard-wattage 9004-type blue headlamp bulb reduced the road lighting ability of a standard headlamp by 67%, and increased glare for oncoming and preceeding traffic by 33%. This apparent contradiction arises because of the way the human eye handles light of different colors. The short-wavelength colors (blue, indigo and violet) are very difficult for our eyes to process and focus on.


Compared to uncolored bulbs, Blue headlight bulbs are able to produce more glare with less light because of the difference between the "signal image", which is what an observer sees when looking at an illuminated headlamp, and the "beam pattern", which is the light viewed from behind the headlamp facing forward, as by the driver of a vehicle. In order for headlamp light to be used by the driver, the light must travel forward from the headlamp to an object, bounce off the object and return to the driver's eyes. As light travels through the atmosphere, it spreads and diffuses according to the Inverse Square Law: The intensity drops as 1/(distance)2. That is, a given headlamp will illuminate an object 2 feet away with 1/4 of the intensity found at the front face of the headlamp, an object 3 feet away with 1/9 of the source intensity, an object 10 feet away with 1/100 of the source intensity, and so on ? and then this loss is redoubled because the light must travel back to the observer's eyes. Remember that the blue filtration prevents the bulk of the light being produced from reaching the road, so the light "stealing" effect of the Inverse Square law becomes greatly magnified: Less light by which to see.

On the other hand, light travels directly from the headlamp to the eyes of the oncoming observer, so the "back to the driver's eyes" redoubling of the Inverse Square law does not take place:More glare. Therefore, for any given distance between the headlamps and the observer, there'll be considerably more light to cause glare than there'll be to allow the driver to see More glare.

Note that some types of "blue" headlamp bulbs are actually legal and not necessarily unsafe; you can read about them here

Does the scattering tendency of blue light affect headlamp performance and road safety in other ways?

Yes, in two ways:

Because blue light scatters very readily in the human eye, casting a beam that's blue-tinted by any amount in a rainy, foggy or snowy environment causes increased perceived backglare for the driver of a car equipped with blue headlamp bulbs.


Also, blue light per secreates increased glare for oncoming traffic. That's because blue light does not trigger a strong pupil-closing response in human eyes. It is yellow light that stimulates the human eye most strongly to constrict the pupil. Due to the comparatively weak pupil response to blue light, the human eye is very glare-sensitive to a blue signal image. With the yellow light filtered out by the blue bulb and prevented from reaching the observer's eyes, the pupils remain wider open than they should, and the eyes are hit with a blast of difficult-to-process blue light.

Isn't the same amount of blue light reaching the observer's eyes whether or not the bulb is blue?

Although the same amount of blue is emitted by a halogen bulb whether it's got a blue-filter coating or not, in the "no filter" case, the remainder of the output spectrum?consisting largely of yellow light?triggers a pupil-closing response in the eyes of oncoming traffic, helping to reduce the short and long term effects of headlamp glare. This glare-protection response is severely compromised when the oncoming signal image is blue.

What about real Xenon headlamps that are blue from the factory?

Genuine arc-discharge (also called metal-halide HID) headlamps run with a very purplish-white character similar to an electronic photoflash, because the same technology is at work?an electrical arc jumping through an atmosphere of Xenon gas. But despite the purplish appearance, this light is actually white with a discrete blue component. That is, most of the light from a Xenon headlamp is white, and there is also blue.

The emerging understanding is that there may be not only a split between the glare-sensitive and non-glare-sensitive amongst the populace, but also among those particularly sensitive to blue, violet and/or near-UV light, and those not particularly sensitive to these wavelengths?with these sensitivities NOT necessarily being linked! This helps explain why some find High Intensity Discharge headlamps menacingly painful and consider them hazardous to share the road with, while others consider them no problem at all.

Researchers are currently working on tweaking the output spectrum of automotive HIDs to eliminate the useless-for-seeing spike in the high blue which causes this reaction in blue-sensitive individuals.

The blue signal images from HID and from blue-tinted halogen lamps arise from two wholly separate phenomena, and therefore can't be directly compared. The main thing is to keep in mind that the blue signal image of an HID headlamp is a throwaway byproduct of a light source that also emits a great deal of white light, while the blue signal image of a blue-tinted halogen lamp is the meager blue ouput left when all the rest of the light has been trapped by the filter.

Are these blue bulbs illegal?

US, Canadian, European and Japanese regulations all call for "white" light. There is no one specific light color that is defined as "white" light; rather, there is a large range of output spectra that are considered "white", and the "white" light is permitted to exhibit visible tints of blue, yellow, green, orange or red. Various regulatory bodies are considering narrowing the "white" standard so that it is less permissive of blue tinting. Such has been the spread of blue headlamp bulbs that many police agencies have purchased in-field beam color testers?they use these on headlamps that look too blue to be legally considered "white".

What about blue-tinted headlight bulbs that I found at a local auto parts store, or on the internet? They're sold as being "DOT Approved". Are these legal?


Probably not. There's no such thing as "DOT approved". DOT does not "approve" products as the European regulatory body does. Rather, the manufacturer of an item of motor vehicle equipment is legally obligated to self-certify that his product complies with all applicable regulations. For some items of equipment, such as headlamp bulbs, the certification takes the form of a "DOT" marking on the bulb base. However, there is no legal obligation for the manufacturer to submit his product for government testing before applying the marking, and many companies go ahead and apply the marking even to bulbs that do not comply with the law. The relevant regulations (US Federal Motor Vehicle Safety Standard 108, Canadian Motor Vehicle Safety Standards 108 and 108.1, and ECE Regulations 8, 20, 37, 98, 99, 112 and 113 all call for "white" light, defined as discussed above, so the statement of DOT compliance itself is false for a bulb that emits a light color obviously different from "white".

Why is there even a market for bulbs like this, if they're so illegal and unsafe?

Many motorists have been confused by marketing claims for the blue bulbs, which falsely and incorrectly equate the blue bulbs' performance with the very expensive arc-discharge ("Xenon") headlamps found on top-line luxury cars. They have been led to believe that by replacing their car's headlamp bulbs with the blue-coated bulbs, their headlamps' performance will be increased. In fact, quite the opposite is true; their headlamps' performance is decreased by the use of blue bulbs.

There is psychology at work in the marketplace, as well. Many of these blue bulbs are sold at very high prices in extremely attractive packaging. It is well known to marketers that the motorist who pays $35 or $45 or even $85 for a set of "special high performance" bulbs will probably perceive a performance improvement even if there is actually none.

Some motorists believe that the blue light makes their car look "cool". This would fall into the same category as the dark plastic headlamp and taillamp covers that are snapped-up by certain drivers for their appearance "enhancement" value, despite the fact that these covers, like the blue bulbs, are illegal and dangerous.

What about bulbs sold as "Xenon" that have clear glass?

Probably no word is used to refer to so many different automotive lighting products as "Xenon", which is an elemental gas. A "Xenon lamp" is a gas-discharge (or High Intensity Discharge)-sourced lamp without a filament. It produces light by maintaining an electrical arc in a highly pressurized environment containing elements?including Xenon&mdashto make the arc emit a great deal of light.

But, Xenon also has a place in lamps with filaments. The addition of a certain proportion of Xenon to the atmosphere in a halogen bulb allows the use of a filament designed to burn hotter, thereby emitting more light, without the rapid burnout of such a filament that would occur without Xenon. But it's not a case of more being better; beyond a certain percentage, Xenon actually reduces the lifespan of the filament.

Halogen headlamp bulbs containing Xenon, in general, are not a gimmick or a scam, if they've got clear glass and are produced by a reputable company. All of the newest bulb designs being produced for new headlamps?such as the H7, H9 and H13 bulb size?include Xenon. Results have been good, with the H7 achieving a higher luminous flux (amount of available usable light) from a given wattage than was achievable with halogen bulbs that didn't include Xenon. So after a few years' experience with H7s, the manufacturers have moved to increase the performance of older, traditional bulb types. One of the techniques used to get such an improvement is to add Xenon to the bulb's atmosphere. There are other valid techniques as well, and not every bulb containing Xenon (or advertised as containing Xenon) is necessarily a performance upgrade.



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Acceptable blue bulbs

Safe, Legal, Blue...But Are They Any Good?

What's the Scoop on "Extra White" Bulbs From Reputable Manufacturers?

You're asking about the current crop of bulbs, widely available in auto parts stores, with a blue absorption filter on the bulb glass, which is there to make the light look whiter. These bulbs are generally safe and legal, though not advantageous, to use in your car.

Some people feel that "whiter" light is better. Some people prefer the appearance of the headlamp when fitted with these bulbs. And then there are the True Believers, who ascribe all kinds of magical (and imaginary) benefits to "whiter" light.

Some companies (PIAA...) even capitalize on this by claiming that their 55W bulbs are as bright as 85W bulbs, among other pseudoscientific claims. Here's how this claim works: Higher-wattage bulbs of a given type generally appear whiter than lower-wattage bulbs. Think of the last time you replaced a 60W bulb in your home with a 100W bulb. So the idea with these "blue" filtered bulbs is to have a lower wattage bulb that mimics the color of a higher wattage bulb, but not its performance. However, there's no getting something for nothing. The altered light color does not mean you're getting more light, or better quality light, just that the light is of a different color.
In fact, you get less usable light from such a bulb than from a regular clear bulb, and here's why: A blue filter removes nonblue components of the light passing through it. Halogen bulbs produce very little light in the blue frequency range. When you put a blue filter on the bulb or lamp, you are reducing the amount of usable light that gets from the glowing filament to the reflector, to the lens and from there to the road. Prove it to yourself using nothing more than the windshield in your car...drive towards a yellow-orange Sodium vapor street light and watch the light as it shines first through the clear portion of the windshield, then through the blue strip at the top. Up there through the blue, it certainly looks "whiter"...but it's also dimmer. If a bulb's sales material focuses on the color of the light rather than the amount of light, you should ask critical questions about the amount of light the bulb produces before choosing to use it.

But If That's True, Then How Come These Bulbs Have All The DOT and ECE Approval Markings Saying It's OK To Use Them On The Road?

The name-brand "extra white" bulbs mostly produce legal light output, true. But there's a lot of wiggle room in the bulb standards that permit two bulbs of the same format to put out significantly different amounts of For illustration of the principle, take a standard HB5 (9007) bulb, which is legally required to produce 1000 lumens of light from the 55W low beam filament at 12.8v, plus or minus 15 percent. That means that in order to be legally certifiable as conforming to Federal standards, a 9007 bulb in the low beam mode must produce between 850 and 1150 lumens. Most folks want to see better at night, not worse, and the way to do that is to use bulbs that produce the maximum legal amount of light. On a dark road, I want bulbs producing 1150 lumens instead of 850, how 'bout you?

So now, where do these legal "blue" bulbs fit on our 850 to 1150 lumen range? Most times, this information isn't available, for it's often made unavailable by bulb manufacturers. Some of the bulbs come with specification sheets giving a wattage and lumen rating, but these don't list actual output, they simply list the nominal specification contained in the Federal standard. The assumption they want you to make is that the bulb you're holding in your hand actually produces the nominal amount of light. In most cases, with blue glass, they don't. About all that can truthfully be said is that they're safe, they're legal, they're not dangerously poor performers like illegal blue bulbs are, but they do not give an actual performance improvement.

So If Blue Filtration Steals Light, How Do They Still Make These Bulbs Produce Legal Output With The Blue Filter?

The manufacturer optimizes the bulb's efficacy through filament and gas-fill technology, so that the uncoated bulb performs up near the top end of the allowable output range, or even slightly above the maximum allowable output. But the bulb is blue, which "steals" some of the light. If the bulb is designed to produce within the legal light level without the blue, the presence of the blue bulb will reduce the output so it's closer to the bottom end of the allowable output range. If the bulb is designed to produce slightly over the legal light level without the blue, then the bulb will perform nearer the middleof the legal range. Here again, though, we can't have something for nothing.It took reputable bulb makers quite a bit of research and development to produce blue filters that would not drop the bulb output below the legal minimum while still altering the appearance of the operating headlamp enough to appeal to consumers after a "whiter" appearance to their headlamps. The cost? Bulb lifetime. The filament changes made to produce enough extra light that the bulb will still be legal despite the blue-filtration losses mean the filament's lifespan is shortened considerably.

Here's actual data for for output and lifespan at 13.2v for H1 bulbs. The numbers here are a composite of values applicable to the products of the three major manufacturers' bulbs. Each maker's product in each category is slightly different but not significantly so, and while the absolute numbers differ with different bulb types, the relative comparison patterns hold good for whatever bulb type you consider. Lifespan is given as Tc, the hour figure at which 63.2 percent of the bulbs have failed:

H1 Bulb Variant / Output Lumens / Life Hours
Standard (plain) / 1550 lm / 650 hr
Long Life / 1460 lm / 1200 hr
Plus+30 High Efficacy / 1680 lm / 400 hr
Plus+50 Ultra High Efficacy / 1750 lm / 350 hr
Blue glass "Extra white" / 1380 lm / 250 hr

Part of the impetus for the development of these bulbs was for the makers of good-quality bulbs to take away a portion of the dangerous "crystal blue" (spark blue, 8500K blue, etc.) type bulb sales and satisfy consumers desiring a different headlamp appearance with a legal and safe product. The retail-level marketers have an easy sell here; Pep Boys offers a "Silverstar Upgrade" service for fifty bucks, for instance. And there are always going to be people lining up to offer glowing testimonials about how much better they think they can see with these bulbs. But can they really?

There's no good evidence that the type of light produced by this sort of bulb actually allows drivers to see better than the type of light produced by a regular, clear bulb. And there've been no studies on the effect of this type of light upon seeing and glare in bad weather, for instance. It has, on the other hand, been shown that these bulbs cause more glare than clear bulbs. Can you see better with this sort of bulb? No, probably not. Some people vigourously defend blue-glass bulbs, insisting they can see better. But that's another problem: they think they can see better than they actually can. There've been no studies to determine exactly how dangerous it is to think you can see better than you really can, but it probably doesn't help safety.
It should be mentioned that while these are critical questions that ought to be asked, they are academic to some degree if what you're deciding is whether to use a no-name bulb or the product of a reputable manufacturer, such as Narva, Candlepower, Osram, Philips, or GE.

OK, So These Extra-White Bulbs Aren't The Best Choice For Maximizing My Headlamps' Performance. What Should I Get Instead?

For those who want the best possible performance from their headlamps and are more concerned with their ability to see rather than the appearance of their headlamps, the major bulb companies offer optimized bulbs without the light-stealing blue glass. Narva RangePower+50 and RangePower+30, GE Night Hawk, and Philips Vision Plus, and Osram Silver Star are the ones to get.

Wait a Minute, Earlier You Said Silver Star Bulbs Have Blue Glass!
It's a name game: Osram, the well-established German lampmaker, sells a line of automotive bulbs they call "Silver Star". These are Osram's top-of-the-range headlamp bulbs, equivalent to Narva RangePower+50, GE Night Hawk, Philips VisionPlus, and Tungsram Megalight Premium. They produce the maximum legal amount of light while staying within legal power consumption limits. They have colorless clear glass.

Osram bought the well-established American lampmaker Sylvania in the early 1990s, so Osram is now Sylvania's parent company. Sylvania also sells a line of automotive bulbs they call "Silver Star", but it's not the same product. The Sylvania Silver Stars have blue glass. Light output is of legal levels, but as with all blue-filtered bulbs, you do not get more light from them. The Sylvania SilverStar bulbs have a very short lifetime, because the filament is overdriven to get a legal amount of light despite the blue glass.

To get the best possible seeing performance at night, don't choose extra-white bulbs.

Thank you for this info to pass on Daniel Stern Lighting (Daniel J. Stern, Proprietor)

Finally- sombody to back up my stuff. NOOOBODY believes me that blue bulbs are bad for other motorists.

 

wow, but who wants to read all of that?

 

I've been saying all of the above for years on various ranger related forums when this topic comes up.

 

depends what "blue" bulbs u are talking bout. i had luminics pure blues in my jeep. i loved them n looked good. now im gettin hids ..the 8000k which has a blueish tint. the hid is suppose to help u see better so how would that affect the visibility compared to a stock halagen bulb?
heres what my pure blues looked like


my pure blues vs a true HID kit

 

i had some eurodesigns "hids" i my vic.............they sucked major butthole.....my silverstars were better

 

the vehicle on the right is much brighter

 

any bulb that has a "coating" on it is crap. the coating causes the light to lose intensity. clear bulbs will always prevail.

 

i wouldnt say brighter but cleaner

 

NYS can like my tail pipe... next they will outlaw blue trucks cause they appear 'blurry' to other drivers.

 

i dont see what the big deal is. I've noticed that the new Escalades put out about just as much glare as my H.I.Ds

 

I had an episode of that **** last night..

I was on 84 east heading home from portland.. blizzard like wind//snow dropping, and a bastard had those crap blue lights in his car, they produce so much damn glare that I nearly lsot sight of the road.. because all of the snow was reflecting it right back at me... I think peopel who go to extremes to see and use these insane HID kits and blue tint bulbs arent doing themselves a favor.. its jsut annoyingly bright for everyone else.

 

And I've been saying it with him!

Good post.

 

I would like to outlaw fart cans that sound like a dying cat..

but as long as the masses do not know what they are buying they will continue to buy said item because the box says so,, I get blinded all the time by those little cars with real and fake HIDs so I doubt it will ever change..