BMW's Laser Headlights | Hacker News Reader

BMW's Laser Headlights

wot.motortrend.com

70 pointsmerraksh74 comments

It might just be me, mainly because I drive an "old" car that doesn't dim/adjust my rear view mirror based on others drivers lights, but I find the uber brightness of other drivers lights to be a real pain these days. Often on the motorway I struggle to see ANYTHING as i'm being constantly blinded by other drivers high power lights behind me and when oncoming. I get its meant to be a safety feature, but for a lot of other road users it's a real nuisance to be blinded on a daily basis.

A good solution would be for modern cars to detect ambient light and adjust accordingly. On a well lit highway with lots of other road users, there's no reason to have these things turned up to 11 all the time. They could safely dial back to 3 or 4.

It isn't the HID lights themselves. All proper HID lights on new cars come with auto-leveling systems which will keep them from throwing light at your rear view mirror. You actually wind up with less light in your rear view than with traditional headlights. When you look at them, they'll look like projector lights and you can see them move up and down as a car goes over a hill, for instance.

The problem is that aftermarket kits are used to install HID lights into standard headlight enclosures. This is base-level idiocy on the part of tinkerers to 'improve' their cars and make them look more modern. There may be a corresponding 'Type R' badge on the back to make the car go faster as well. These will throw a TON of light at your rear view and blind you. These are illegal in most states and I wish this law were enforced without exception everywhere in the world.

This is the correct answer. When my car starts up, my lights lower and then rise again to adjust, although I didn't know this also happens when driving over a hill.

It does not happen when driving over a hill. There are two different levelling functions. What you describe is the "homing" procedure for the stepper motors (typically) that do the levelling.

Static levelling is mandatory for HID headlamps, and that adjusts the headlamp level according to load, etc, for example based on suspension level sensors. As the name says, it is static, so it doesn't do anything while the vehicle is moving.

Dynamic levelling compensates for driver braking and acceleration, but I have not seen a production system that works for hills (how could it without information about where the crest is?). Typically, the systems work to ONLY react to the driver doing something, not road features like speed bumps or inclines.

Neither levelling procedure works to actively reduce glare for other drivers when in turns or going over a hill.

That makes more sense. My dad's car has dynamic leveling with braking and acceleration. I noticed it in conjunction with hills for that reason.

The problem is not the brightness, IMHO. The real problem is that, at least in the US, no one seems to care about keeping their headlights aimed properly, which in combination with the abundance of trucks with headlights mounted higher than a normal driver's head, leads to insane glare. As much as mandatory vehicle inspections are annoying, this would be my one reason to support them. (Not that it seems to matter, here in HI they have annual inspections, but the inspection facilities don't seem to give a damn.)

Of course, a brighter misaligned headlight is worse, but an old halogen headlight creates plenty of glare if misaligned, while a super bright headlight is fine as long as it's not aimed at your eyes.

I'm not sure about other countries, but all vehicles sold with HID (the bright blue headlights that many people find annoying) headlights in the US must come with an auto-leveling system. I'm almost 100% certain that the standards are the same or higher in Europe.

The fact that (as you point out) those bright blue headlights are especially offensive to many people would suggest that the auto-leveling system is not doing its job.

The more blue the lights are, the greater the chance they are not factory; some schmuck stuck HID bulbs in halogen housings. This means no auto-leveling, no proper beam focusing, etc. It is already widely known that doing so is a Very Bad Idea (tm), but some people have absolutely no deference to their fellow drivers on the road.

The OP said, "The real problem is that, at least in the US, no one seems to care about keeping their headlights aimed properly..." I'm only pointing out that proper adjustment isn't the issue.

The matter of HID headlight annoyance is well-trodden territory in automotive circles. Owning a car with them equipped, I appreciate the additional visibility. On the flip side, living in an area where they are common, I appreciate that they can be blinding if you're caught in the beam.

I find the blue headlights annoying because they're blue, not because they're bright.

My latest complaint is LED brake lights. Many models seem to be making them very bright -- to the point where they blind me when I am behind such a car. At stops, I sometimes find I have to look away from the car in front of me and the road, both due to discomfort and to having my night vision -- despite their being largely "red" -- destroyed.

I thought there were regulations for such things -- for headlights, as well -- but either they are too lax or no one is enforcing them.

Also, it seems typical of today's trends. Brighten up e.g. one's headlights for one's own convenience, even if and as to an excess that inconveniences everyone else or even puts them at risk.

P.S. Also, many "modern" headlights have a very small and bright core source of light, as opposed to the larger reflector of "older" designs that does not create such an intense, localized spot.

And the "blue-er" light -- harder on one's night vision.

LED brake lights definitely seem too bright on some cars.

And there's a new trend... super-bright LED daytime running lights, actually bright enough to be distracting at high noon, and configured so that just one side switches off when the blinker turns on (giving this absurd half-lit or winking effect).

I was behind a car today where the middle "third" brake light would actually blink, so weird and distracting -- hopefully an illegal after-market mod.

Definitely one place I would have thought regulation would have stopped design from impacting safety. Next auto makers will decide brake lights don't even have to be red, because who cares about night vision if you have freakin laser beams in your headlights, right?!

The point of the flashing brake light is to get your attention, apparently it's legal at least in the EU.

Legal in the U.S. a lot of dealers started doing this in the 90s as an add on to the spoiler.

I'm seriously considering turning my high-beams on when behind one of these godawful supernova-machines at an intersection at night. Definitely won't buy one with them.

You mention this, but a smart self-dimming rear view mirror can't help at all against the incredible brightness of oncoming headlights. I have been literally blinded while going over CA highway 17 at night (don't let the "highway" designation fool you; it's a twisty mountain road abutted by cliffs), an obvious safety issue.

I don't understand why it's legal to have headlights so bright. Manufacturers say having headlights brighter than everyone else makes you safer because you stand out. By the point where no one can even see, any putative safety benefit has been lost. Headlight brightness seems like a close analog of overfishing to me. :/

The drive for ever-brighter lights also ignores the safety of the road users without lights, who become increasingly harder to spot. An example of road users without lights: people.

I know it's unfashionable to give a shit about people when you're driving a car, particularly people on foot, who if they were at all important enough to care about would surely be driving a car, but - well, what can I say? Bleeding heart, that's me.

You appear not to have read the part about BMW's new pedestrian spotlight feature. Which may raise another issue about deer (or people) freezing in the spotlights.

It's not the obscuration of pedestrians from the driver with the bright lights, it's the obscuration of the pedestrian from the other driver being blinded by the super bright headlights. In the brightness the pupil closes and the driver looses any night vision. If you were approaching this situation from the other direction it could be extremely difficult to see the reverse-spot lighted pedestrians.

Also the obscuration of everything from the pedestrian. When walking, if you have a car coming upfront it's there for a long while (since it might be fast but you're always slow), and at night your night vision goes away for a very, very long time. Having to stop, close your eyes and turn around every time you hear a car closing in does not make for efficient or fun walking about.

That may explain the deer in the headlights phenomenon, if real. They could be waiting for their eyes to readjust. Agree that this feature would be undesirable for pedestrians (and cyclists, if also targeted). And I suspect the spotlight is unlikely to avert any more than a small number of accidents. However, it seems quite a strong sales feature for BMW - enhancing the driver/owner's sense of control.

I was under the impression that deer freeze whenever they feel threatened by anything. Freezing when spotlighted is just a particular case of how deer always react to threats.

NB: "highway" doesn't mean multi-lane controlled-access expressway or freeway. It's any road open to the public, though generally between towns (as opposed to a local surface street). In the UK it can refer to footpaths as well as vehicular roads.

It's not just you, lights on most cars are just too damn bright and severely affect other drivers' night vision. I have no idea why they are considered "safe."

However, BMW's new ultra bright lights will surely fail to gain traction, because BMW tends to attract a class of ultra-considerate driver that puts the safety of other drivers first and foremost, and surely BMW drivers would never stand for something like this.

BMW also need to work on their indicator fluid systems. So many of their cars seem to have run out, which leads to other drivers being unable to see the indicators the BMW drivers so conscientiously use.

About nine person out of ten I know aren't aware of the fact that the rear view mirror in most cars can be manually set to "night mode". The rear view mirror has two positions: one for day-time and one for night-time (which dims the brightness of other cars' headlights).

There's a manual switch which accepts two position and which is located on the back of your rear view mirror.

It's something you need to switch manually twice a day: once in the morning to put it back in "day mode" and once at night, when it becomes dark. You don't need to reconfigure anything: the position of the rear-view mirror stays correct and you continue "viewing the same thing", just dimmed enough as to not be blinded by bright headlights in your rear-view mirror.

Honestly, as I wrote earlier, most people I know who drive cars are totally unaware of that switch even though they're driving since 20 years.

Why not just wear sunglasses?

When I feel that the oncoming vehicle's lights are too bright, they get my high beams, which stay on them, despite their frantic high beam flashing. If more people did this, perhaps these people would switch back to their OEM lights.

EDIT: Not talking about the lights described in the article, but people who replace their cars' original lights with brighter ones.

> When I feel that the oncoming vehicle's lights are too bright, they get my high beams, which stay on them, despite their frantic high beam flashing. If more people did this, perhaps these people would switch back to their OEM lights.

Sounds like you're really endangering other people's lives in response to an annoyance.

Not in response to an "annoyance". I feel that they are selfishly endangering me and the other drivers on the road.

Even if that's the case, the correct response is not to endanger them right back. That's like people who tailgate because they think the person in front of them is going too slow, or the ones who slow down because they think the person behind them is going too fast. Two wrongs don't make a right; they just make things twice as bad, or worse.

Oh so you decided to help them? How nice.

These lights FTA are OEM, though a lot of tuner cars and lifted trucks aren't I suppose.

You're either very principled in that you're willing to get seriously injured over a minor cause, or you haven't really thought this through methinks...

I have a VW with xenon projectors and the self-leveling feature should ensure this doesn't happen, but occasionally people do flash me. I assume their eyes are dilated from the weed.

Xenon lights are obnoxious because they are so much bluer than standard lights, they are that much more blinding; outdoor lights that are too blue (or full-spectrum) have the paradoxical effect of making everything darker by contrast, and much harder to see.

I can't stand cars that have xenon lights, and I was glad to see their numbers start to decline in the last couple years.

My car also self-levels its xenon lights, and they are never at the other drivers' level. I never see anyone being bothered by them at all.

I never see anyone being bothered by them at all.

WTF. How on earth would you know whether drivers going in the opposite direction were being blinded by your lights?!

You can see very clearly where the higher intensity area of the beam cuts off, and he probably doesn't get flashed by oncoming cars.

If only there were some sort of signal other drivers could make to indicate my beams were too high!

Xenon lights actually have a lower cutoff on the drivers side because the designers were aware of onlooking from the opposite direction (and on the left of the car in the U.S.)

They are bothersome, you see this comment saying they are bothersome.

Yes, but I don't see anyone flashing at me to turn them down...

What possible good would that do? You can't make them un-xenon. If I flash my lights or not, you'll still just keep toodling along blinding everybody in the oncoming lane.

If I see ultra-bright lights, I assume the other driver has the high beams on and flash them. If you can tell that they have misconfigured low beams, you wouldn't do that, but I'm going by my experience and assume that at least a few drivers would act the same way.

You know what happens when you flash a teenager who has super deluxe Xenon lights? You get flashed back, double blinded.

"Turn them down." What do you have a rheostat on your headlamps? Keep them "down."

The blue headlights you see are different than VW factory HIDs. 8000K or 10000K aftermarket halogens marketed as xenons to car tuners that look like crap.

I don't understand how self-leveling works. If you're on a down-slope, won't they level themselves relative to the horizontal and shine in everyone's eyes then?

Besides, there's no helping that everyone's screwed on convex roads. Coming over the top of a hill, your headlights will necessarily blind everyone coming from the other direction.

Self-leveling compensates for car posture due to its load, not due to road incline. Think - full trunk with no passangers vs an empty trunk.

Well the problem is how low is the other vehicle? A modern Range Rover sits much higher than an MX5.

Recentish Range Rovers are easily the worst. But most SUVs are generally pretty bad, with speed bumps, slight hills, or - yes - even a simple right-hand bend giving you an eyeful of piercing cold light. With the modern HID-/LED-/etc.-type bulbs, there's no falloff at the edge of the beam, so the moment your eyes are even slightly inside the light cone, they get zapped.

I drive a BMW 3 series, which I don't believe is an especially low-riding car, but I still notice this quite a lot! I'm 6'2" and have the seat basically bolt upright, so my eyes are pretty far off the ground.

The biggest problem is how well are the other vehicle's headlights aimed. When i'm on the highway at night, i find that the Mercedes and Range Rovers with their HIDs are never an annoyance, because the lights shine at the ground rather than into my windows. GMC/Chevy SUVs and Pickups seem to be the worst offenders - they've got the xenon lights, but they're just a drop in replacement for the standard headlamps, so they shine straight out in front.

Yeah, thankfully I have a dimming rear-view mirror.

I assume people with blinding lights are willingly acting malicious against others on the road knowing their overpowered lights reduce visibility for others. Lines like yours don't do much to break this mentality.

Keep assuming drug usage while the reality of you blinding others is readily observable by peers around you. Self leveling projector lights beaming straight into my cab.

My understanding has always been that lasers have a very low efficiency. I don't understand how it can possibly be more efficient to use a laser than an LED. But maybe my thinking dates back to the days of gas discharge lasers and solid state lasers are just that more efficient?

Some solid-state lasers have pretty high efficiencies, as much as 74% in this case: http://phys.org/news/2011-05-scientists-high-efficiency-cera...

I think I've seen references to 50-60% efficiency for production lasers, though I could be mistaken on that. Given the very low efficiency of lighting systems in general (incandescent bulbs waste 95%+ of input energy, even CFLs and LEDs are in 20-40% range AFAIR), that's very high.

> Like Xenon headlights, power is immediately cut to the laser headlights in the event of any damage.

As a software engineer this statement really bugs me. Once something is damaged in the real world you can't assume control over the system anymore. The part that cuts or provides the power to the laser might have been the thing damaged. Maybe if they had added a qualifier like "power should be cut" instead of such certitude.

There is a concept in mechanical engineering where something can have a "normally closed position." You see this often with valves. The idea is that the normal resting position of the actuator prevents flow throw the valve. The effect is that the valve automatically shuts itself in the event of power loss or system failure. I presume they have implemented something similar. I might guess that the lasers may not be turned on if the system cannot somehow validate the integrity of the lens the lasers shine into. Same thing with the part that cuts or provides power to the laser. It's been a while since I studied circuits as a mechanical engineering undergrad, but I believe that you can also design circuits that behave in a similar fashion.

"BMW says its laser system is 1000 times brighter than LED headlights but uses half the power." Yeah, that's bull, unless they're using some very creative definition of "brighter". LED headlights put out about as much light as do standard halogen incandescents, about 1000-1500 lumens per fixture. A million lumens? You'd be hard pressed to tell that apart from the sun. Also theoretically impossible, as LEDs are already at 10-25% maximum luminous efficacy.

I googled "yellow phosphorus," and this page, run by an Angelo State University professor, says that it's the same as white phosphorus, which I understood to be dangerous.

http://www.angelo.edu/faculty/kboudrea/demos/burning_phospho...

The page explains: "White phosphorus is highly reactive, and spontaneously ignites at about 30°C in moist air. It is usually stored under water, to prevent exposure to the air. It is also extremely toxic, even in very small quantities."

Aside from cutting power to the headlights, I wonder how BMW keeps the white phosphorus from causing trouble during a crash.

Bear with me here-- I understand lasers to be highly specific wavelength diode light that is bounced around in a combination of prisms and mirrors to create highly concentrated, highly directional light.

In this case, it's then diffused again through a yellow phosphorus lens.

I'm not doubting the numbers in efficiency gain, but I'm having a hard time figuring them out. Seems that there can only be loss from converting this light "back and forth" (but more than likely I don't understand how lasers work).

Well, let's assume these lasers are 10x as efficient as LEDs used in headlights. Even if you lost 70% of the light in the process of exciting phosphorus, you'd still have a net gain.

My question would be: are modern headlights really that much of a drain?

Decent LEDs are, currently, about 6x less efficacious than the theoretical maximum of any light emitter, as measured by the human eye. Incandescents are much poorer performers, of course.

http://en.wikipedia.org/wiki/Chemiluminescence

Be interesting to see how these compare in the real world to my current favorite headlights, the Hella brand units fitted to higher end Volkswagens since 2009.

They're a much better "daylight" approximation than comparable systems, e.g. the units fitted on the Jaguar XF are pretty jarring in comparison.

The beam shape adjusts based on roadspeed and window wiper activity, the rain pattern is excellent when snow is falling.

For the manufacturer the part is cheaper than comparable high end units, partly due to removing the need for external ride height sensors. Most HID setups have a ride height sensor on the front suspension and one on the rear, the Hella units have gyroscopes packaged inside the cluster removing the need for external parts.

The final winning point for me is the freedom left to the manufacturer in designing the rest of the headlight cluster around the HID unit. Consequently replacing any other bulbs in one of these units is complete child's play. Contrast this with 0.5 hours "book time" for the new BMW X5 - the front bumper has to be removed (involves disconnecting headlight washer pipes and plenty more besides).

I don't get all this commotion about laser lights and their 1000x efficiency when that's just a concept maybe 5 years in the future. The lightspot technology (looking with IR cameras for people and highlighting them, so that drivers see them 112 feet sooner) seems much more interesting and should safe a lot more lives than lights with different technology that scale better.

I'm concerned about the responses in this article. I drive on the same roads every day and have never experienced an issue with other cars having very bright normal lights to the point of blinding me. Perhaps they should get their vision checked and see whether it is safe for them to drive at night. It may be that their eyes are too senstive for it to be safe.

Well, I'm glad that you, specifically, have never had that issue. Might you have noticed the large number of complaints registered in the years since HID lights became common?

I think it is possible that they are more sensitive to the particular color of those lights. If the majority of the population doesn't have the problem, it may never be fixed without identifying what the issue might be. It might be like a color blind person complaining that red and green lights on the road look the same when most people don't think they do.

Also, no, until this article & comments, I have never heard this complaint.

Audi is putting them on the 2014 LMP car.

Wait for the Chinese clones of this that every idiot will retrofit to their car, thereby endangering everyone on the road like the do now with their illegal blue headlights.

Can somebody explain the 1000 times efficiency gain? I thought that LED is over 10% effective on power so I don't get this.

I guess one factor in this "1000 times more efficient" scam is the higher photon output per surface area. LEDs efficiency drop a lot when maximizing photon per surface area. Edge emitting blue lasers have a much better power conversion rate than LEDs when driven at higher input power. The much better photon/surface area plus higher input power create a much narrower and brighter beam. Therfore only ~10% loss opposed to ~30% with LEDs...

http://m.phys.org/news/2013-11-laser-diodes.html

http://www.winlab.rutgers.edu/~crose/capstone12/entries/Soli...

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