Headlights: Explained.

"Mathias Rios" (Mars478) 09/06/2013 at 11:45 • Filed to: None

10

31

There seems to be a lot of misconceptions when it comes to headlights. Considering that headlights are one of the most important features of cars you'd think there wouldn't be so much disinformation about them. In this article I want to clear up these misconceptions and explain all the permutations and different variations of car headlights nowadays. Manufacturers tend contribute to the many terms and contradictions in the headlight world.

I am going to separate this article into three separate sections.

Headlight Housings

Bulbs

Other relevant info/miscellaneous

SECTION 1: Headlight Housings.

The headlight "housing" is basically where the bulb lives. I am using the term "housing" to describe where the bulb is mounted and situated to provide the optimum light output and beam pattern.

Reflector

(Image from !!!error: Indecipherable SUB-paragraph formatting!!! )

Reflectors are by far the most common kind of headlight, although nowadays that may be changing. I am not going to bore you with the science of how this kind of headlight works, but basically, the headlight bulb is mounted within the housing and chrome paint "reflects" the light that the headlight outputs onto the road. The little chrome piece that is covering the actual bulb is in place to prevent the bulb from blinding oncoming drivers, and to control the beam pattern. This headlight style seemed to be dying out but it seems that they may be making a !!!error: Indecipherable SUB-paragraph formatting!!! (One internet to whoever IDs those headlights).

Projector

(Fun fact, that's my car.)

Projector headlights, a relative newcomer in the headlight world, as their name suggests they "project" light onto the road. The bulb here is mounted within a "projector bowl", which similar to the reflector housing, reflects all of the light towards the magnified projector lens (there are different kinds of lenses and projectors, and !!!error: Indecipherable SUB-paragraph formatting!!! is an awesome resource for learning and buying projector based equipment) in a metal housing which is chrome painted. The light then hits a piece of metal that is shaped like the pattern of light that will be projected onto the road. Why this is like this is some sort of marvel of science and !!!error: Indecipherable SUB-paragraph formatting!!! . The projector housing lives within the headlight and is usually a removable piece, and has lead some enterprising individuals to retrofit projectors from more modern cars (NOT entire headlights) into their reflector based headlights if there is not a facelift version with projector headlights. Generally projector headlights provide superior light output with a sharp cutoff line and focused light.

SECTION 2: Bulbs

The bulb is what provides and creates the light that gets reflected/projected onto the road. Generally for most of car history, these bulbs have been little glass tubes vacuum sealed and containing a filament and halogen gas. However in recent times, as with almost everything with cars, new challengers to the venerable halogen gas based headlight have appeared.

Halogens

(Image from !!!error: Indecipherable SUB-paragraph formatting!!! )

Halogen bulbs are the most common kind of headlight bulb. There are many different kind of halogen headlights, all to fit different reflectors and projectors. These headlights provide the familiar yellowish light that older folks will remember when staring at a highway. These are generally pretty boring headlights.

H(igh)I(ntensity)D(ischarge)/Xenon

(Image from !!!error: Indecipherable SUB-paragraph formatting!!! )

HID/Xenon headlight bulbs are a relative newcomer compared to the halogen bulb. While HID/Xenon is technically more than a bulb, including a ballast and igniter, to keep it simple we can ignore that bit for now. Xenon lights provide the white/bluish light you see out of the headlights of more modern cars/retrofit cars or the headlight of choice for !!!error: Indecipherable SUB-paragraph formatting!!! (P.S., if you installed an HID kit in your car and it looks like that please buy !!!error: Indecipherable SUB-paragraph formatting!!! and have your buddy aim it your forehead). This kind of headlight provides superior light output and better color (this may be a personal preference) than halogen style headlights.

LEDs

(From !!!error: Indecipherable SUB-paragraph formatting!!! )

These are the newest kind of headlight "bulb" (they technically aren't a bulb), and only recently have they been implemented as headlight units. Mercedes, Audi, Lexus, Acura, and BMW have been experimenting with these kinds of headlights lately, and to be very honest I do not know very much about them since I haven't driven or been in a car equipped with such headlights. The upside to LEDs is that they draw very little power, are decently small, and can be used in all sorts of creative ways. LEDs have been previously used in taillights, along in blinkers and in interior lighting.

Lasers (future)

These are the cutting edge of headlight technology. The next headlight frontier. A good article about these headlights is !!!error: Indecipherable SUB-paragraph formatting!!! .

!!! UNKNOWN CONTENT TYPE !!!

SECTION 3: Other relevant info/miscellaneous

Now that we have covered all the different types of technologies and versions of headlights, possibly the MOST important thing you can take away from this article is that ALL of these things listed are interchangeable with each other. An HID/Xenon is not always a projector. A halogen headlight can be a projector. LED headlights come in projector and reflector versions. Point is, these can all be combined, and to describe a headlight accurately you need two separate terms. "Projector Xenon/HID", "Reflector LED", "Halogen Projector".

The term Bi-Xenon really peeves me off. Let's talk about what a Bi-Xenon is. Bi-Xenon is basically marketing jargon for a projector headlight that activates a solenoid when the High beams are activate. The solenoid in the projector moves downwards, allowing for more light in the projector bowl to actually escape through the magnified glass. This basically provides a "high" beam even though it is still the same beam. Now here is where it gets stupid, an american Fiat 500 which is a car with Halogen projectors, has this same setup, albeit with halogens. Fiat describes this setup on their website has "Bi-Function Halogen headlights". Bi means two and Bi-xenon/halogen (insert your joke of choice here) would imply two , and unless the car has two projectors, this description doesn't make sense. Oh, and also, a Bi-Xenon can be a reflector based headlight with an HID. Second gen Priuses with HID/Xenons have this setup.

The first american car with HID/Xenons was a Lincoln Mark VIII with a proprietary Sylvania DC(!) setup.

A lot of cars have Halogen high beams to supplement the Xenon/HID or to act as the sole high beam. Xenon/HIDs are not very suitable as separate high beams since they have a longer warm up time and flashing them drastically reduces their lifespan. A lot of cars also have a halogen beam to complement the HID/Xenon with a solenoid (aka bi-xenon).

If you're wondering what kind of setup I run on my car, I run Hella E55 projectors with the "bi-xenon" solenoid wired to the high beam halogen of my car so that when I flash to pass, the solenoid activates along with the halogen high beam. I run Morimoto D2H 6000K Xenon/HID headlight bulbs from The Retrofit source. The actual headlights I bought from ebay and they had a RIDICULOUSLY bad projector and beam output, and I put proper projectors in place of these sucky ones. If you're interested in what my light pattern looks like check !!!error: Indecipherable SUB-paragraph formatting!!! out. Keep in mind that is downhill...

The WORST thing you can do, is install an HID/Xenon kit in a reflector (OR projector) that was made for a halogen headlight. Usually these headlights are designed specifically for the light output of a halogen and since HID/Xenons give out more light than a halogen it screws up the light output and light leaks all over the place and you generally end up blinding every oncoming driver.

A DRL is NOT a headlight.

Foglights aren't headlights either.

That's it. Thank you for reading, please comment if I have messed anything up/typo'ed something. If you have a retrofit headlight car I'd love to see it along with the story that led up to it. I apologize if something here doesn't make sense because it is in my mental language, and that my 4AM sleep deprived mind made something sound stupid. Thank you.

lonestranger > Mathias Rios 09/06/2013 at 11:37

1

This headlight style seemed to be dying out but it seems that they may be making a resurgence (One internet to whoever IDs those headlights).

2013 BMW 7 Series.

Mathias Rios > lonestranger 09/06/2013 at 11:39

1

Well done! You have been awarded one internet.

Mattbob > Mathias Rios 09/06/2013 at 11:45

0

No love for sealed beams?

Mathias Rios > Mattbob 09/06/2013 at 11:55

0

Eh I figured they fit in with the reflectors/halogens. Am I wrong to think that?

Mattbob > Mathias Rios 09/06/2013 at 12:07

0

No, that's pretty much what they are. Except more awesome because they are glass and don't look like crap when your car gets old. You just replace them. Also, LED's aren't really that much more efficient than an HID setup, and perhaps even halogen, (I have to look up the figures). I know they don't beat florescent in building applications. Their main advantage in my opinion is super long life, instant on/off, and dimming capability via PWM.

Mathias Rios > Mattbob 09/06/2013 at 12:15

0

Haha. Sealed beams do look pretty awesome. I was considering putting in a bit about the interesting US legislation that ONLY allowed cars to have 7 inch circular sealed beams from like 1939 to 1984 I believe, which to me is amazing. The manufacturers still managed to style their cars differently despite not being able to use the headlight as a styling device. And that EVERY CAR had the same headlight from that period of time, and you could go to a store and the kind of headlight you need would always be in stock. Cool, but weird at the same time.

If you could find the figures on the LED setup, I'll definitely edit this post to reflect that. Like I said I don't know too much about the LED headlights, but I THINK (I may be wrong) that they consume less energy than traditional lighting setups.

Mattbob > Mathias Rios 09/06/2013 at 13:08

0

Ok, doing some research. A sylvania xenarc HID light ( this ) uses 35 watts and produces 3200 lumens. Thats 91.4 Lumens per watt. This site advertises an LED conversion kit that outputs 1200 lumens at 22 watts. This is only 54.5 Lumens per watt. They say that you lose some efficiency with the extra housing needed for HIDs, but it should still be as, or more efficient. I just chose two random examples, but im sure you could find more if you were so inclined.

Mattbob > Mathias Rios 09/06/2013 at 13:23

0

Well if you could manage to use these LEDs in your car, you could get 109 Lumens per watt, but the require over 80 watts. You could run them at less though because they output waaay more light than you need (9100 lumens at 80 watts). You would also need a driver circuit because they need about 40 volts. Someone with the means should build a kit to install these! I could design the driver if you want!

magman007 > Mathias Rios 09/06/2013 at 14:58

0

my DRL's are my projectors.

Mathias Rios > magman007 09/06/2013 at 16:53

0

What kind of car do you have? The only car that I have seen that has Projector LED DRLs is some more recent BMW's such as the 6 series. If it is a single projector in the bumper, then I'm PRETTY sure that's considered a foglight.

Mathias Rios > Mattbob 09/06/2013 at 16:56

0

WOW. That is quite the LED. I would probably be willing to experiment with the high beam in my car and place that in place of where the halogen bulb goes. So what is the final result of this discovery? I think LEDs generally use a little less power but can be (like anything really) be upgraded to consume more power. The problem with most LED conversion kits is that they generally suck a LOT. LEDs as headlights haven't evolved enough yet, at least for the layman.

magman007 > Mathias Rios 09/06/2013 at 17:23

0

No Led Projector, just a xenon I believe, its an o6 STi

Mattbob > Mathias Rios 09/06/2013 at 18:18

0

no, for the same brightness, your are going to use more power with an LED. You have to look at the efficiency. But LEDs are the better choice really even if they use a bit more power, because you never really have to replace them. They are getting better however, and could overtake HIDs. The huge LED I cited is sort of an extreme example and isn't super practical in a car as it puts out way more than you need and would need a rather large heatsink. Its more of a street lamp LED or projector.

Mathias Rios > magman007 09/07/2013 at 01:35

0

I'm pretty sure no car comes with a stock projector with an HID, and DRLs are usually just LEDs with no purpose of light illumination, just a styling cue and so that other cars see you. What you have I believe is a foglight projector with an HID modified into it.

Evan, Pope Of Jalopnik by Self-Appointment > Mathias Rios 09/07/2013 at 14:57

0

I'm a little confused by what you're trying to say but there are lots of cheap and older cars that just use the low beams as DRLs. LED DRLs have only developed in the last few years, before that they were bulbs as well. Except for BMW that used their halos, although those weren't LED either, they were something else.

Mathias Rios > Evan, Pope Of Jalopnik by Self-Appointment 09/07/2013 at 15:32

1

OK you are right, I made a mistake. I for some reason was thinking about LED drl strips

thebigbossyboss > Mathias Rios 10/10/2014 at 06:56

3

Jeep Liberty!

thebigbossyboss > Mathias Rios 10/10/2014 at 07:07

1

Great article Mathias. Man, my car was in headlight hell for the longest time. My passenger side light was broken and my drivers one wouldn't stay up on alignment and was totally fogged so it basically pointed 3 feet in front of the car. Fun. Finally got it fixed, and defogged my light myself.

Then the passenger side broke again. Argh.

Mathias Rios > thebigbossyboss 10/10/2014 at 13:06

0

Hey thanks! I am very curious... how did you find this article when I wrote it over a year ago?

thebigbossyboss > Mathias Rios 10/10/2014 at 13:17

0

kinja I guess. Came from oppo this morning.

hyderius > Mathias Rios 10/25/2014 at 05:30

1

By the way, there are now some plug-n-play setups to convert old-school sealed beam headlight systems to LED's. Like these: http://www.gelighting.com/LightingWeb/na…

They're crazy expensive right now, but I'm sure the prices will drop once Chinese knockoffs show up.

NET625 > Mathias Rios 05/03/2015 at 01:56

1

The LED fog lamps for the Triumph Tiger 800 XCX work the same way. An array of LEDs shining down into the reflector. Not the best picture, the LEDs are in the half circle at the top.

rockyred > Mathias Rios 12/06/2015 at 01:06

0

So I really like the appearance of headlights with black housings and clear lenses, regardless of the type of light used. If I have projector headlights, and went into the housing and painted over the chrome with heat resistant black, would that ruin the headlight's efficiency?

Mathias Rios > rockyred 12/07/2015 at 12:39

0

As long as the surface you’re painting isn’t a headlight reflective surface, such as the projector bowl or the reflector for the high beam, you’re totally in the clear to paint over the chrome. In fact I may be doing the same thing in the near future.

pjhusa > Mathias Rios 02/06/2016 at 11:55

0

Facelift W163 headlight unit. May I please have my Interwebz?

(Fun fact, that’s my car.)

mightycpa > Mathias Rios 06/10/2016 at 14:20

0

That’s exactly what I want to do too, paint the chrome, except it’s for my projector fog lights.

These:

http://www.ebay.com/itm/USA-98-99-…

What do you think?

Mathias Rios > mightycpa 06/10/2016 at 16:16

0

Would look awesome. Thanks for reading! May I ask how you managed to stumble upon this article that I wrote nearly three years ago? Genuinely curious! Thanks! :)

WhyteKnyght71 > Mathias Rios 01/31/2017 at 04:35

1

Thanks much for the clarity on this occasionally murky subject (puns intended). I was a parts guy and technician for nearly 10 years and wasn’t sure the diff between standard (reflector) and projector beams. Turns out, my deductions were correct, but I appreciate the general breakdown. I found this article as one of the top search results on my Android Google app. The title is the reason I clicked here first.

My first car was a ‘71 Chevelle that I converted from sealed-beam to capsule style in the late 90s and was going to try and retro-fit a halo system (there were no kits back then) but my baby decided she wanted to commit auto-cide in the form of a car-flagration (more puns, it’s 1:30am, sue me). I recently inherited a Mazda6 with projectors and wanted to confirm (or debunk) my evaluation of the difference. Turns out, like telescopes, it really is all in the name. Thanks again.

P.S. I enjoyed your writing style, informative yet fun. You should be writing for Road and Track or Car and Driver. They could use a little more fun in their write-ups.

Mathias Rios > WhyteKnyght71 01/31/2017 at 12:11

0

Hey Thanks! Means a lot- I’m glad this article was able to help you out nearly 4 years later :)

Johcu > Mathias Rios 10/24/2017 at 16:50

0

Thanks for the explanation. I previously was quite confused by the term bi-xenon and wondered if I need 4 bulbs for my car. Like 2 for dip beam and 2 for main beam. You have nicely cleared that up.

Also the solenoid dip/main explains the sharp cut off, which is disconcerting and too damned close for me in my Jaguar XJ 2015 model.

I’m now actively looking to replace my Oem xenons with hopefully brighter more powerful ones as the standards are too dim.

ZilVidu > Mathias Rios 12/17/2017 at 19:56

0

Thanks for this explanations, just want to ask some comments/additional info:

If the “high” beam in HID is still the SAME BEAM that is just re-directed by a solenoid, does it mean that in HID/Xenon, the brightness level of Low-beam and High-beam are pretty much the same?

Whereas my understanding in most Halogen lamps, the high-beam, aside from being pointed farther away down the road, is also brighter than the low-beam. That’s because halogen headlamp lights up 2 filaments when high-beam is activated, instead of just one filament when it’s in the low beam. If this is so, then the high-beam halogen is therefore very useful if you are speeding up on a pitch-black highway and want to see farther down the road.

Hope to see your comments. Thanks