The Headlight Brightness Wars(theringer.com)
theringer.com
The Headlight Brightness Wars
https://www.theringer.com/2024/12/03/tech/headlight-brightness-cars-accidents
206 comments
this seems like wild generalizations from both angles you present and I can't figure out where you actually fall in this, as the narrator.
I thought it was pretty clear. He finds that cars primarily contribute nuisance to his life, so he doesn't like them that much anymore.
> Chris Trechter, a lighting-focused engineer who used to work for Magna International, the largest automobile parts manufacturer in North America, told me the company would adhere to 108 in making headlights for clients like General Motors but that the rule is “archaic.” “It does not account for LEDs,” he said, “and there are giant loopholes that allow you to throw basically unlimited light as long as you meet all the other aspects of 108.”
There are multiple references to this idea that you can have a basically unlimited brightness headlamp because the way it's tested is flawed. Anyone know how the testing process works?
There are multiple references to this idea that you can have a basically unlimited brightness headlamp because the way it's tested is flawed. Anyone know how the testing process works?
They measure at a certain point. Jason Cammisa points it out pretty clearly in an episode of Carmudgeon, with the money quote either here[0] or in the link direct to YouTube here[1]:
> On a recent episode of the Carmudgeon Show podcast, auto journalist Jason Cammisa described a phenomenon occurring with some LED headlights in which there are observable minor spots of dimness among an otherwise bright field of light. “With complex arrays of LEDs and of optics,” he said, “car companies realized they can engineer in a dark spot where it’s being measured, but the rest of the field is vastly over-illuminated. And I’ve had now two car companies’ engineers, when I played stupid and said, ‘What’s the dark spot?’ … And the lighting engineers are all fucking proud of themselves: ‘That’s where they measure the fucking thing!’ And I’m like, ‘You assholes, you’re the reason that every fucking new car is blinding the shit out of everyone.’”
[0] https://www.theringer.com/2024/12/03/tech/headlight-brightne...
[1] https://youtu.be/MkwjMV2of_8?t=697
> On a recent episode of the Carmudgeon Show podcast, auto journalist Jason Cammisa described a phenomenon occurring with some LED headlights in which there are observable minor spots of dimness among an otherwise bright field of light. “With complex arrays of LEDs and of optics,” he said, “car companies realized they can engineer in a dark spot where it’s being measured, but the rest of the field is vastly over-illuminated. And I’ve had now two car companies’ engineers, when I played stupid and said, ‘What’s the dark spot?’ … And the lighting engineers are all fucking proud of themselves: ‘That’s where they measure the fucking thing!’ And I’m like, ‘You assholes, you’re the reason that every fucking new car is blinding the shit out of everyone.’”
[0] https://www.theringer.com/2024/12/03/tech/headlight-brightne...
[1] https://youtu.be/MkwjMV2of_8?t=697
https://news.ycombinator.com/item?id=42332716
It sounds like there is an area that is focused on for the test and they can engineer the lights to avoid putting too much light in that area.
It sounds like there is an area that is focused on for the test and they can engineer the lights to avoid putting too much light in that area.
Casually newer GM vehicles are one of the worst offenders together with Tesla with their poorly-shaped light beaming, that’s maybe a cosenquence of having a front end in the vehicle so high that the the headlights are level with the roof of “normal” sedans.
tbf newer Teslas all have matrix LEDs but they aren't enabled in the US because of NHTSA. I bet it's just a feature flag suite away too.
The current Rivian cars have this, enabled, in the US.
What's a matrix LED?
A technical kludge around drivers who refuse to dip their hi-beams by creating a dynamic mask around other vehicles - matrix LED headlights act as a bright, low-resolution projector that keeps other vehicles unlit, but lights up everything else.
How is getting all of the advantages of high beams without the blinding factor of other drivers a kludge? It’s a huge benefit. Auto high beams already exist.
> How is getting all of the advantages of high beams without the blinding factor of other drivers a kludge?
Because it's not just other drivers inconvenienced by super bright lights - people in their homes, pedestrians out if sensor range and camera systems are unaccounted for. Also, because a simpler solution exists for 99% of the times drivers abuse high beams, and has existed for 50+ years.
Driver ed books in most jurisdictions spell out where high beams ought to be used, and well-lit city streets are not one of them. It's kludge because it's being offered up as a technical solution to make up for rule-breaking drivers who use high beams as an default-on, when they ought to be default-off. Don't use high beams unless you need them, which should be a minority of the time. The bulk of society seems to have decided not to be inconvenienced by only seeing 20 car lengths at night, screw everybody else's night vision.
Because it's not just other drivers inconvenienced by super bright lights - people in their homes, pedestrians out if sensor range and camera systems are unaccounted for. Also, because a simpler solution exists for 99% of the times drivers abuse high beams, and has existed for 50+ years.
Driver ed books in most jurisdictions spell out where high beams ought to be used, and well-lit city streets are not one of them. It's kludge because it's being offered up as a technical solution to make up for rule-breaking drivers who use high beams as an default-on, when they ought to be default-off. Don't use high beams unless you need them, which should be a minority of the time. The bulk of society seems to have decided not to be inconvenienced by only seeing 20 car lengths at night, screw everybody else's night vision.
This sounds like a failing of the system to not dip the high beams in the presence of sufficiently bright street lighting. I'm not sure how mandating matrix headlights be not used is the solution here.
My auto high beams don't come on at all during city driving that is reasonably well lit, since its detecting something to cause them to dip.
My auto high beams don't come on at all during city driving that is reasonably well lit, since its detecting something to cause them to dip.
> I'm not sure how mandating matrix headlights be not used is the solution here.
That's not what I'm suggesting at all - matrix headlights absolutely should he used - clearly some drivers "need" them, I'm just identifying them as a kludge for asshole drivers who can't be bothered to flick a finger or thumb to dip their lights.
That's not what I'm suggesting at all - matrix headlights absolutely should he used - clearly some drivers "need" them, I'm just identifying them as a kludge for asshole drivers who can't be bothered to flick a finger or thumb to dip their lights.
Again, how is it a kludge? If you want to argue standard 'auto' high beams are a kludge, then maybe... but matrix headlights are performing a function that is literally impossible by a driver. Having high beams still illuminate an area where no cars are is strictly better, especially on the proper locations where it should be used (poorly lit rural areas), and there is no way to do that without matrix headlights.
This is an abdication of duty, or else an unwillingness to admit flawed decision-making, at NHTSA.
Any time I am approached by a new vehicle going over a minor hill, I am blinded by their LEDs. Makers like BMW obviously market such blinding lights as power, awareness, etc. but it is a danger to everyone on the road.
If you're in the middle of nowhere highway, hit the brights. Otherwise, these lights need regulated. I wonder if there is a resistance mod that could be put in to lower the brightness for someone who cared to.
Any time I am approached by a new vehicle going over a minor hill, I am blinded by their LEDs. Makers like BMW obviously market such blinding lights as power, awareness, etc. but it is a danger to everyone on the road.
If you're in the middle of nowhere highway, hit the brights. Otherwise, these lights need regulated. I wonder if there is a resistance mod that could be put in to lower the brightness for someone who cared to.
I’d argue the biggest offender here is Ford/GM
The German cars will at least attempt to dim the beam or auto turn off high beams, in Europe they’ll even divert the beam around you but for some reason we don’t allow that in the US. I drive a BMW as my daily and the computer makes every effort to not blind people.
GM and Ford I just get constantly blinded by gigantic pillars of LEDs, regardless if I’m driving another truck or a low sports car.
The German cars will at least attempt to dim the beam or auto turn off high beams, in Europe they’ll even divert the beam around you but for some reason we don’t allow that in the US. I drive a BMW as my daily and the computer makes every effort to not blind people.
GM and Ford I just get constantly blinded by gigantic pillars of LEDs, regardless if I’m driving another truck or a low sports car.
I think the NHTSA just approved these, so hopefully they’ll start being more common
https://www.nhtsa.gov/press-releases/nhtsa-allow-adaptive-dr...
https://www.nhtsa.gov/press-releases/nhtsa-allow-adaptive-dr...
But they stupidly didn't follow the SAE's recommendations and made it harder to implement in the US by deviating from the standard used in the ROW.
https://www.newsweek.com/nhtsa-roadblocking-headlight-techno...
https://www.newsweek.com/nhtsa-roadblocking-headlight-techno...
Tesla is the worst - their DRLs are blinding if you're off to the side of them in a sedan like I drive. Apparently, they're supposed to be USER aimed / aligned AFTER delivery, but pretty sure only 5% of drivers have even the faintest of clues about any setting in their car other than "pair phone".
I'm not saying no other cars have issues, including the obviously misaimed 70s light-in-a-box bulbs. And don't get me started on the number of cars with ZERO lights, or only DRLs (no tail lights) at night here in the Bay Area (CA).
I am constantly struggling to avoid glare at night from crazy lights. If I could wave my hand and fix one brand, without question it would be Teslas - they're systematically bad. All others seem like one-offs (bad maintenance, post-accident/replacement-misaligned, etc).
I'm not saying no other cars have issues, including the obviously misaimed 70s light-in-a-box bulbs. And don't get me started on the number of cars with ZERO lights, or only DRLs (no tail lights) at night here in the Bay Area (CA).
I am constantly struggling to avoid glare at night from crazy lights. If I could wave my hand and fix one brand, without question it would be Teslas - they're systematically bad. All others seem like one-offs (bad maintenance, post-accident/replacement-misaligned, etc).
>>And don't get me started on the number of cars with ZERO lights, or only DRLs (no tail lights) at night here in the Bay Area (CA).
As sort of a personal mea culpa, shortly after I got a new car, I realized I had done a nighttime drive with just daytime running lights. I leave the lights on Auto usually but it's relatively easy to hit the headlight dial with a finger when activating the turn signal. (Or, as I think was the case here I had just gotten a state inspection and the lights were just turned off.) I'm more aware now. Something seemed a bit off but it was a fairly new car.
As sort of a personal mea culpa, shortly after I got a new car, I realized I had done a nighttime drive with just daytime running lights. I leave the lights on Auto usually but it's relatively easy to hit the headlight dial with a finger when activating the turn signal. (Or, as I think was the case here I had just gotten a state inspection and the lights were just turned off.) I'm more aware now. Something seemed a bit off but it was a fairly new car.
Most Tesla headlights have matrix functionality (the ability selectively dim areas of the headlight that would be aimed at another car) but this is not enabled in the US.
> in Europe they’ll even divert the beam around you but for some reason we don’t allow that in the US
Is this true? Moving beams away from incoming traffic certainly was a feature (called "Active High Beam") on Volvo XC90 that I rented in California a few years ago. I've no idea if this was a US market car, or imported from somewhere, but it certainly existed and worked.
Is this true? Moving beams away from incoming traffic certainly was a feature (called "Active High Beam") on Volvo XC90 that I rented in California a few years ago. I've no idea if this was a US market car, or imported from somewhere, but it certainly existed and worked.
All of the German automakers have this feature that they all call something different, but yes. The current NHTSA regulations prevent it from being deployed in the US, as another commenter pointed out though it seems like the NHTSA finally relented and approved it so I’d expect it to start showing up. My car already has the hardware and it’s a software switch to flip it on, so I imagine most other newer German cars are the same.
My understanding is that in the U.S. it's allowed to have headlights that dynamically turn on and off the high beams depending on whether it sees a car coming. The more advanced Euro version has a spatial light modulator in the headlight that dims the light specifically in the direction of the oncoming car, while leaving the high beams on for rest of the area in front of the car.
> headlights that dynamically turn on and off the high beams depending on whether it sees a car coming
A nice feature in theory, my mother-in-law's Toyota has this, but it doesn't work very well.
A nice feature in theory, my mother-in-law's Toyota has this, but it doesn't work very well.
It's the default startup setting in my Honda CR-V. Too many things in cars are being automated like this. Not being able to dial in a windshield wiper speed and only having an "Auto" option drives me crazy because it usually guesses wrong.
I agree with most of what you said, but BMW lights autodim very aggressively because they know it's annoying as hell. I know because i found how to verify that's enabled, and was testing it just hours ago.
Around here, there are geriatric drivers aplenty at certain times of year who drive with brights on all the time, hills or straightaways or anything. very annoying. including in daylight.
Around here, there are geriatric drivers aplenty at certain times of year who drive with brights on all the time, hills or straightaways or anything. very annoying. including in daylight.
[deleted]
Last year I did a little roadtrip along the West Coast and through parts of Nevada and one thing that boggled my European mind was that, at night, on ordinary roads cars coming from the other direction always had their high beams on and never switched to their low beams as we got closer to each other. Same thing when cars were behind me. Is switching to your low beams to avoid dazzling other drivers not a thing in the US?
Those are almost certainly not the brights! You'll find that out real quick if you flash your brights at them, and see the real brights!
In Europe lights have much better quality optics, that are less blinding to oncoming drivers at the same light output. For the most part, these are not US legal, and the even same European car models when sold in the USA have much worse lights that dangerously blind oncoming drivers.
I have always (illegally) retrofitted my vehicles with European versions of the headlights, and I can see much better, and blind other drivers less. It is absolutely insane that having safe headlights is illegal in the USA.
In Europe lights have much better quality optics, that are less blinding to oncoming drivers at the same light output. For the most part, these are not US legal, and the even same European car models when sold in the USA have much worse lights that dangerously blind oncoming drivers.
I have always (illegally) retrofitted my vehicles with European versions of the headlights, and I can see much better, and blind other drivers less. It is absolutely insane that having safe headlights is illegal in the USA.
This feels like the real story. Why are European headlights deemed unacceptable in the US?
The answer is constantly changing, but there is a general trend of the USA being slower to make improved lighting technology legal, and USA car companies having no interest in adopting improved lighting technology, often even after it is legal.
In general car headlights in the USA have to be DOT compliant, meeting a strict set of regulations... and the new and innovative or unusual designs on high end foreign cars can fall outside those for one reason or another.
For example, back in the 70s and 80s the only compliant lights were extremely dim disposable sealed beam light bulbs with an integrated lens and reflector. European cars had high end optics with large glass lenses and mirrors that used a replaceable H4 style bulb, but the American versions had to swap that entire system for something with a low quality disposable bulb. Car enthusiasts would often buy the better lights from overseas and swap them in. While technically illegal, not cop is going to ticket you for not blinding them enough. Nowadays at least American cars do have replaceable lights and not sealed beams.
A more modern example, is that European cars have long used dynamic/adaptive lights that actively detect and block the light going towards oncoming vehicles by dynamically reshaping the beam- a much more effective system than just having low beams that point lower. They also have steerable headlights that point away from oncoming traffic into turns, and automatically point the lights down if the vehicle suspension squats in the rear from a heavy load or bump. While they've long been legal and widely used in Europe, they are now legal in the USA as of 2 years ago- for example you can now order a new VW with "Dynamic Light Assist" option, which actively reshapes the beam.... but this is so recently legal almost no vehicles on the road have it yet.
In general car headlights in the USA have to be DOT compliant, meeting a strict set of regulations... and the new and innovative or unusual designs on high end foreign cars can fall outside those for one reason or another.
For example, back in the 70s and 80s the only compliant lights were extremely dim disposable sealed beam light bulbs with an integrated lens and reflector. European cars had high end optics with large glass lenses and mirrors that used a replaceable H4 style bulb, but the American versions had to swap that entire system for something with a low quality disposable bulb. Car enthusiasts would often buy the better lights from overseas and swap them in. While technically illegal, not cop is going to ticket you for not blinding them enough. Nowadays at least American cars do have replaceable lights and not sealed beams.
A more modern example, is that European cars have long used dynamic/adaptive lights that actively detect and block the light going towards oncoming vehicles by dynamically reshaping the beam- a much more effective system than just having low beams that point lower. They also have steerable headlights that point away from oncoming traffic into turns, and automatically point the lights down if the vehicle suspension squats in the rear from a heavy load or bump. While they've long been legal and widely used in Europe, they are now legal in the USA as of 2 years ago- for example you can now order a new VW with "Dynamic Light Assist" option, which actively reshapes the beam.... but this is so recently legal almost no vehicles on the road have it yet.
100%
Given that you said "always", I suspect they were the regular headlights of those cars. Which is really what the article is getting at. Especially because the height of cars in the US can be much higher than you might see in Europe (e.g. a lifted F-250), which point directly into the face of a driver in a smaller car. I hate it.
It's absolutely a thing. Sometimes people forget, and you can remind them by flashing your highbeams at them. However that's maybe one in fifty encounters in my experience, most people remember most of the time.
A lesser known trick is you can flash your highbeams before cresting a hill or going around a blind turn to warn drivers on the other side. I rarely encounter other drivers who do this, but when I do it almost always works.
A lesser known trick is you can flash your highbeams before cresting a hill or going around a blind turn to warn drivers on the other side. I rarely encounter other drivers who do this, but when I do it almost always works.
I am currently having that experience here in Eastern Mountain California now that it's dark and winter.
It's hard to tell really if always-on high beams are now common or if SUVs + superbright beams makes it seem that way, especially given there are a lot of hills that can make any car's high beams seem on.
Still, I feel like "civility" here is breaking down and not turning off high beams may be a part of it (though I'm aware that feeling may be coloring my perceptions).
It's hard to tell really if always-on high beams are now common or if SUVs + superbright beams makes it seem that way, especially given there are a lot of hills that can make any car's high beams seem on.
Still, I feel like "civility" here is breaking down and not turning off high beams may be a part of it (though I'm aware that feeling may be coloring my perceptions).
> always-on high beams are now common or if SUVs + superbright beams
I think it's a little bit of both. I believe the latter started the trend, and that confusion has led other people to just say screw it.
I think it's a little bit of both. I believe the latter started the trend, and that confusion has led other people to just say screw it.
> Is switching to your low beams to avoid dazzling other drivers not a thing in the US?
It 100% is when I was learning to drive in the 90's. Growing up I remember driving up the desolate back-roads of upstate NY on our way to VT and my father loosing his shit when some moron kept their high beams on. It was rare.
I bet a lot of it has to do with modern car automation where auto dimming and other features are expected by newer drivers to just work and they blissfully drive around expecting the car to do everything for them. Laziness rendered by convenience.
It 100% is when I was learning to drive in the 90's. Growing up I remember driving up the desolate back-roads of upstate NY on our way to VT and my father loosing his shit when some moron kept their high beams on. It was rare.
I bet a lot of it has to do with modern car automation where auto dimming and other features are expected by newer drivers to just work and they blissfully drive around expecting the car to do everything for them. Laziness rendered by convenience.
Both of my cars (BMW and Nissan) have the ability to auto-switch to low beams when oncoming headlights are detected. It works great. But you have to press a button on the end of the turn signal wand to enable it. And it disables when you turn the car off. My wife and kids have no idea how to use this feature. I tried to explain it a few times, but they weren't interested.
It is a thing. Your experience doesn’t at all match my experience driving on the West Coast for the last few decades.
Maybe, but also I get flashed by people thinking I have my high beams on when I don't, so could be mistaken.
Because your headlights are too bright.
You are hurting them.
Take the hint and complain LOUDLY at your dealer until they do something about it.
Take the hint and complain LOUDLY at your dealer until they do something about it.
Same, I drive a new model Suburban and constantly get flashed. I think it is the combination of the LED headlights and height at which they sit. I wish there was something I could do about it, but it isn't user adjustable.
You can absolutely adjust the angle of your headlights in any modern vehicle. There's usually a screw somewhere reasonably accessible. Drop it literally like 1 degree.
Check with your dealer, there was a recall on some GM lines due to a DRL not dimming at night causing excess glare.
https://static.nhtsa.gov/odi/rcl/2022/RCLRPT-22V903-6333.PDF
https://static.nhtsa.gov/odi/rcl/2022/RCLRPT-22V903-6333.PDF
I'm not an expert, but it's likely to be an alignment issue they could address at a shop.
It is in the Southeast at least for about 90% of cases
How about taillight brightness?
I'm not sure if this has gotten better in recent years, but there are a bunch of high-end vehicles (looking at you AUDI) with extremely bright red LED taillights that are just painful to sit behind at a red light.
I'm not sure if this has gotten better in recent years, but there are a bunch of high-end vehicles (looking at you AUDI) with extremely bright red LED taillights that are just painful to sit behind at a red light.
There are a lot of oblivious drivers operating their vehicles with their tow-lamps enabled, who are not towing. There's a button by the light cluster, for example on the Audi Quattro; you may wonder what it does - or maybe you thought it was a do-nothing button. It makes your tail lights equal to the brightness of your brake lamps. CEASE USE.
Are these rear fog lights? They tend to be bright, and lots of people always drive with their fog lights on for some reason.
This- a lot of European cars have rear fog lights, which people sometimes leave on all of the time, but really should only be used in low visibility weather.
Yeah, but it's not just the brightness. It's also the strobing, which is highly distracting and nausea inducing.
I'm assuming it saves $0.47 per car to use slow PWM to set brightness rather than a linear regulator.
Does slow PWM save money?
I first noticed slow PWM in factory tail lights on Cadillacs somewhere around the turn of the century. I pointed it out to my dad one night when we were out for a walk, and told him how to see it on a car that was disappearing down the road.
It took a few seconds for him to understand and to observe it himself, and then he said "I can accept that you're annoyed by that, but maybe they just build them that way because they think it looks cool."
Ever since that night, I have always assumed that slow PWM was used as a deliberate visual effect: After all, General Motors isn't really trying to squeeze a few pennies out of a new Cadillac [that's what Chevrolet is for!].
(I also think it's a dick move on the manufacturer's part, whether it is to save forty-seven cents, or if it is to look cool, or even if it is both.)
I first noticed slow PWM in factory tail lights on Cadillacs somewhere around the turn of the century. I pointed it out to my dad one night when we were out for a walk, and told him how to see it on a car that was disappearing down the road.
It took a few seconds for him to understand and to observe it himself, and then he said "I can accept that you're annoyed by that, but maybe they just build them that way because they think it looks cool."
Ever since that night, I have always assumed that slow PWM was used as a deliberate visual effect: After all, General Motors isn't really trying to squeeze a few pennies out of a new Cadillac [that's what Chevrolet is for!].
(I also think it's a dick move on the manufacturer's part, whether it is to save forty-seven cents, or if it is to look cool, or even if it is both.)
This prompted me to go look for a better answer, and I found a good candidate: pulsed current at a relative low frequency (~60hZ) allows higher perceived brightness from smaller/cheaper LEDs. From my perspective, it is undesirable to increase the brightness of car taillights relative to what was typical with incandescent bulbs or to make them flicker.
https://electronics.stackexchange.com/questions/164078/why-i...
https://electronics.stackexchange.com/questions/164078/why-i...
The PWM function is built-in into the electronic switches that drive the light outputs, so you can programmatically control the brightness, it also accepts different switching frequencies so it’s just a matter of increasing the frequency for the “strobe effect” to be unnoticeable. The advantage of these switches over analog are several, including output diagnostic and lower power dissipation.
Keeping in mind that it's on a moving vehicle, and road users often pan their eyes around rapidly, the frequency would need to be higher than for many other situations.
Or they could use a variable linear regulator with no flickering at all.
Or they could use a variable linear regulator with no flickering at all.
Is a higher switching frequency problematic, somehow? Is there an upper bound on switching frequency that makes LEDs difficult or unnecessarily inefficient or something?
There's nothing I'm aware of relating to the electronics that drive them that would place such a low bound on frequency that the resulting pulses would be visibly distinct.
MOSFETs are generally good for > tens-of-KHz frequencies, and so are the hardware PWM channels in every-day MCUs.
There's nothing I'm aware of relating to the electronics that drive them that would place such a low bound on frequency that the resulting pulses would be visibly distinct.
MOSFETs are generally good for > tens-of-KHz frequencies, and so are the hardware PWM channels in every-day MCUs.
The effect described in the StackExchange answer to increase perceived brightness at a lower power level seems to rely on a low frequency and short duty cycle. It's not necessary to use that effect given that LEDs rated for higher power levels are available, and the amount of power is insignificant at the scale of a car, but it does allow the use of cheaper LEDs.
Linear regulators waste a lot of power and generate a lot of heat, so that's why they don't use them.
Switching regulators can be used without having PWM on the LEDs though.
LED flashlights use constant current sources, I don't know if that's infeasible or not for some reason on high-power car headlights.
Personally I wouldn't be surprised if it's just to save the 47c. The car industry is competitive.
Switching regulators can be used without having PWM on the LEDs though.
LED flashlights use constant current sources, I don't know if that's infeasible or not for some reason on high-power car headlights.
Personally I wouldn't be surprised if it's just to save the 47c. The car industry is competitive.
A series of web searches found one of the driver boards often used in LED tail lights: the Valeo b003809. Some images of it show an identifiable TLE4242 linear driver IC.
I was starting to suspect that would be the case after reading the explanation about slow PWM and a short duty cycle resulting in greater perceived brightness from cheap LEDs that aren't rated for much power. Direct drive from the car's electrical system wouldn't result in the constant brightness seen in LED tail lights because the voltage is lower at idle, so there has to be some kind of regulation.
There would be little reason to use a more efficient, more expensive switched-mode power supply, though an aftermarket replacement for the Valeo board does use one. Even an inefficient LED design will be far more efficient than an incandescent bulb, and the power requirement of any taillight is trivial relative to a modern car's electrical system. Linear makes the most sense for the application.
Linear regulators aren't rare in LED flashlights nor is direct drive with PWM on a FET for low modes. Neither is good in flashlights, but that only matters to the manufacturer if their customers know the difference. Most customers don't; lights marketed to discerning customers use a switched-mode power supply.
I was starting to suspect that would be the case after reading the explanation about slow PWM and a short duty cycle resulting in greater perceived brightness from cheap LEDs that aren't rated for much power. Direct drive from the car's electrical system wouldn't result in the constant brightness seen in LED tail lights because the voltage is lower at idle, so there has to be some kind of regulation.
There would be little reason to use a more efficient, more expensive switched-mode power supply, though an aftermarket replacement for the Valeo board does use one. Even an inefficient LED design will be far more efficient than an incandescent bulb, and the power requirement of any taillight is trivial relative to a modern car's electrical system. Linear makes the most sense for the application.
Linear regulators aren't rare in LED flashlights nor is direct drive with PWM on a FET for low modes. Neither is good in flashlights, but that only matters to the manufacturer if their customers know the difference. Most customers don't; lights marketed to discerning customers use a switched-mode power supply.
The problem could be the LED driver itself rather than the vehicle driver output. Most LED lights use some kind of PWM or multplexing, but people only notice the bad or rather the slow) ones. It’s easy to find out, just take a few videos at different frame rates an you’ll see.
Those early Cadillac LEDs were the worst, though I've seen some new models from other manufacturers whose taillights are almost as bad.
Is it possible to control LED brightness with a linear regulator? I am surprised to hear it - when I was making light effects with LEDs years ago, I understood PWM to be the only practical mechanism, due to the strongly non-linear conductivity curve.
But maybe it's possible, if you just want to fix your LEDs at a specific brightness which never changes, that you could find exactly the right current level...?
But maybe it's possible, if you just want to fix your LEDs at a specific brightness which never changes, that you could find exactly the right current level...?
As a flashlight nerd and reviewer, I know a number of ways to control the brightness of an LED, and linear regulators are a fairly common one. It's important to note that a linear regulator can be designed to target a specific voltage, or a specific current. LEDs should be regulated with current for the reason you mentioned.
One that I think would work well in cars is a fixed-current linear regulator like the AMC7135. There's no need to do anything fancy to control it; put a 7135 in the circuit and the LED gets 350mA. Two in parallel and it gets 700mA, and so on. More fancy is a linear regulator with variable current output.
Linear regulators are a low-end option for flashlights, with switched-mode power supplies being preferred for their superior efficiency. A car has a lot more energy to work with and more mass with which to sink and radiate heat.
One that I think would work well in cars is a fixed-current linear regulator like the AMC7135. There's no need to do anything fancy to control it; put a 7135 in the circuit and the LED gets 350mA. Two in parallel and it gets 700mA, and so on. More fancy is a linear regulator with variable current output.
Linear regulators are a low-end option for flashlights, with switched-mode power supplies being preferred for their superior efficiency. A car has a lot more energy to work with and more mass with which to sink and radiate heat.
You can but it isn’t efficient. You lose (V_in - V_out)*I_led Watts to heat if you use a linear regulator.
You might ask why not connect them in series and get the voltage difference as small as possible. But the “forward voltages” of LEDs are highly temperature dependent and car battery voltage is (somewhat) engine rpm dependent (might swing between 12 and 13.8V between no rpm and some rpm. It’s kept flat at 13.8V)
You might ask why not connect them in series and get the voltage difference as small as possible. But the “forward voltages” of LEDs are highly temperature dependent and car battery voltage is (somewhat) engine rpm dependent (might swing between 12 and 13.8V between no rpm and some rpm. It’s kept flat at 13.8V)
Linear regulators can do it easily, if used in a constant-current driver configuration. That constant can be variable, so regulated-current might be a better name.
Your classic LM317 linear regulator can do it pretty easily, with a potentiometer instead of a fixed resistor to set the output current. Section 9.3.3[1] of the datasheet describes the circuit, though in practice you might add a couple of capacitors for stability.
There are also a number of discrete-transistor circuits. A current mirror with a rheostat is probably the simplest, though not generally ideal performance.
[1]https://www.ti.com/lit/ds/symlink/lm317.pdf?ts=1734395381792...
Your classic LM317 linear regulator can do it pretty easily, with a potentiometer instead of a fixed resistor to set the output current. Section 9.3.3[1] of the datasheet describes the circuit, though in practice you might add a couple of capacitors for stability.
There are also a number of discrete-transistor circuits. A current mirror with a rheostat is probably the simplest, though not generally ideal performance.
[1]https://www.ti.com/lit/ds/symlink/lm317.pdf?ts=1734395381792...
Interesting! I have used plenty of LM317s with LEDs, but I never thought of using them to regulate brightness - I would just pick whichever resistor corresponded to the forward current specified in the emitter datasheet. Didn't realize that there was enough room on the curve to use current control as a meaningfully configurable brightness setting.
[deleted]
>strobing
I've never seen a strobing tail light. The most "strobing" I've seen are some brake/tail lights that flash for 1-2 seconds right after they're turned on (to alert drivers better? still annoying imo).
I've never seen a strobing tail light. The most "strobing" I've seen are some brake/tail lights that flash for 1-2 seconds right after they're turned on (to alert drivers better? still annoying imo).
Almost all LED taillights strobe, but too fast for most people to see the strobing due to persistence of vision. But if you move your eyes side to side while taillights are in your field of view you can catch a glimpse of the strobing.
That blinking is usually a dealer installed add-on that can be hard to get removed (and usually involves modifying the factory wiring, thanks), generally on the high mount brake light (CHMSL). I personally believe these lights violate the law (and I think this letter supports that position [1], if it's still current?), but dealers gonna deal.
But I think the poster is complaining about the higher frequency flickering that's supposed to be imperceptible... if you don't perceive it, that's better for you. Unfortunately, I regularly see it especially when moving my heads or eyes and find it pretty distracting. There's circuit design techniques to reduce the flickering, but saving pennies here and there adds up, so there you go.
[1] https://www.nhtsa.gov/interpretations/20288ztv
But I think the poster is complaining about the higher frequency flickering that's supposed to be imperceptible... if you don't perceive it, that's better for you. Unfortunately, I regularly see it especially when moving my heads or eyes and find it pretty distracting. There's circuit design techniques to reduce the flickering, but saving pennies here and there adds up, so there you go.
[1] https://www.nhtsa.gov/interpretations/20288ztv
I doubt this even saves pennies. These lights are driven by an IC, and the current is regulated because the supply voltage is nowhere near stable enough to get away with an unregulated drive circuit. The mention of the TLE4242 chip upthread quite clearly indicates that there’s an entire wire from the ECU to the driver to control it. All that’s needed is for the IC to support some way to change the current regulator set point instead of flashing the LED. Sure, this would add a handful of transistors and maybe a capacitor or two inside the IC, and it will cost some R&D, but it won’t affect the unit cost in any meaningful way.
(This could be as simple as a filter that turns the duty cycle into a current target. This feature is nearly ubiquitous in off-the-shelf “dimmable constant current” line-voltage-input LED drivers from basically every supplier (e.g. Mean Well). The tricky bit would be to get the thing to turn on quickly enough without annoying brightness swings, so some actual care in the filter design and frequency selection would be required. Or one could use 0-10V control (also ubiquitous) or have just two states plus off or have digital control… there’s no shortage of perfectly fine solutions.)
(This could be as simple as a filter that turns the duty cycle into a current target. This feature is nearly ubiquitous in off-the-shelf “dimmable constant current” line-voltage-input LED drivers from basically every supplier (e.g. Mean Well). The tricky bit would be to get the thing to turn on quickly enough without annoying brightness swings, so some actual care in the filter design and frequency selection would be required. Or one could use 0-10V control (also ubiquitous) or have just two states plus off or have digital control… there’s no shortage of perfectly fine solutions.)
https://en.wikipedia.org/wiki/Stroboscopic_effect . See the "Root Causes" and "Mitigation" sections for a discussion of LEDs.
Also: https://standards.ieee.org/ieee/1789/4479/
For me, it's the sudden sensation of being mashed in a Berlin disco. While driving!
Also: https://standards.ieee.org/ieee/1789/4479/
For me, it's the sudden sensation of being mashed in a Berlin disco. While driving!
I know some cars have the blinking when you are applying sudden pressure to the brakes. To alert people behind them they may be stopping quickly. People use their hazards in some states for the same reason.
And nobody bothers putting on the handbrake any more (helped by the proliferation of automatics). I often use the visor when stationery behind a car
The blame lies completely with the NHTSA.
https://www.newsweek.com/nhtsa-roadblocking-headlight-techno...
https://www.newsweek.com/nhtsa-roadblocking-headlight-techno...
Adaptive lighting isn't the best solution either.
Here in the Netherlands there are lots of complaints from people on bicycles who get blinded by "adaptive" lights that don't adapt, or don't do so quickly enough, probably because they dont recognise the "profile" or shape of a bicycle.
The problem is even worse when coming over a hill.
Here in the Netherlands there are lots of complaints from people on bicycles who get blinded by "adaptive" lights that don't adapt, or don't do so quickly enough, probably because they dont recognise the "profile" or shape of a bicycle.
The problem is even worse when coming over a hill.
What's better?
this sounds like the CGP Grey video about solving traffic whose solution* would completely eliminate pedestrian crossings.
My rule of thumb is that f a solution is extremely comfortable for drivers then it is likely damaging to everybody else.
* basically turning all cars in a coordinating mesh network
My rule of thumb is that f a solution is extremely comfortable for drivers then it is likely damaging to everybody else.
* basically turning all cars in a coordinating mesh network
this is sort of tangentially related: if you're feeling like every car on the road has overly bright headlights, get your eyes checked. i've been hearing people complain about bright headlights, and noticed myself feeling really sensitive to it lately.
turns out i have a slight astigmatism, and wearing glasses when driving at night makes other cars headlights infinitely more tolerable. there's still the odd vehicle that has obnoxious headlights, but i went from most cars being intolerable to most cars being totally fine.
turns out i have a slight astigmatism, and wearing glasses when driving at night makes other cars headlights infinitely more tolerable. there's still the odd vehicle that has obnoxious headlights, but i went from most cars being intolerable to most cars being totally fine.
I've seen images representing what light looks like with an astigmatism and that's absolutely what I see. Always been like that for me but I've never had glasses. If I ever get a car again I might have to see about getting a prescription for something to correct that.
Some of us are also just stuck with naturally sensitive eyes, unfortunately.
This is also true
I gotta say, the tone of this article offends me. They basically put things as "these people are complete weirdos though they might have a tiny spec of a point, chuckle".
And "war"? You can see these a few voices in the wilderness with no leverage 'cause this little society presents the average person with no way to do anything about the many "little annoyances" of this society presents even when they add up to something nightmarish or happen to strongly affect a minority.
And "war"? You can see these a few voices in the wilderness with no leverage 'cause this little society presents the average person with no way to do anything about the many "little annoyances" of this society presents even when they add up to something nightmarish or happen to strongly affect a minority.
Isn’t political leverage defined relative to the average person?
So this seems like a tautology.
So this seems like a tautology.
I think they've always mistakenly focused on headlight brightness (using wattage as a proxy), but the focus should really be on beam shaping and optics quality.
Most cars sold in Europe have had much brighter lights than the same models sold in the USA since the 70s and 80s, yet by using better optics, they had a sharp clearly defined cutoff that virtually eliminates all oncoming light to other drivers, while lighting the road itself and the side of the road a lot more. Yet, these brighter and more courteous lights had been illegal in the USA.
I have a German SUV with extremely powerful HID headlights, and on top of that, it is lifted- pretty awful for other drivers right? No! Because it has good optics with a sharp cutoff, and steerable headlights with tilt sensors on the suspension, and always keeps the headlights pointed low enough to not blind oncoming drivers, even when going over a bump. On top of that, it steers the lights into turns, and away from oncoming drivers around bends.
Most cars sold in Europe have had much brighter lights than the same models sold in the USA since the 70s and 80s, yet by using better optics, they had a sharp clearly defined cutoff that virtually eliminates all oncoming light to other drivers, while lighting the road itself and the side of the road a lot more. Yet, these brighter and more courteous lights had been illegal in the USA.
I have a German SUV with extremely powerful HID headlights, and on top of that, it is lifted- pretty awful for other drivers right? No! Because it has good optics with a sharp cutoff, and steerable headlights with tilt sensors on the suspension, and always keeps the headlights pointed low enough to not blind oncoming drivers, even when going over a bump. On top of that, it steers the lights into turns, and away from oncoming drivers around bends.
I think the problem with modern cars in the US is quite the opposite - the increasingly well-tuned optics are exacerbating the problem.
Modern cars indeed have a very sharp, well-designed cutoff at the top of their beam patter. This makes correct vertical aiming very sensitive: aim just slightly too high and oncoming drivers get nearly the full output of your headlights; aim just a little too low and your vision range becomes noticeably limited. Older headlights, with much softer upper beam patterns, were far more forgiving.
The problem is bad enough that, on my 2022, I carry an 8mm wrench in the glovebox so I can adjust the headlight aim as needed. This is particularly important because the aim is sensitive enough that loading or unloading the back of the car changes the level stance enough to put the headlights noticeably out of aim.
Compounding this problem, it's very common for cars to have poorly-adjusted headlights from the factory, often too high. I think this is because the factory adjusts the lights for a combination of the rated loading and not getting complaints from new buyers (which is more likely when they are aimed too low). Additionally, at least in the US, the "correct" alignment of the headlights is defined by the position of the headlight themselves (the top cutoff should be level to the position of the bulb, is the simple version, although I think the more formal version specifies a measuring distance and slight upward tolerance). This means that tall vehicles like pickup trucks will blind oncoming drivers of shorter vehicles when properly adjusted---once again, this was a much more forgiving problem when the top of the light pattern was much softer, but has become extremely noticeable now that headlights emit their full output almost all the way to the top.
I understand that auto-leveling headlights and headlights with a cabin height adjustment are much more common in Europe. For whatever reason they're rare in the US, and I think it might be difficult to get them to comply with US regulations which I understand to be somewhat archaic on this topic. Auto-leveling is probably the best technical solution available.
How does it work on your German SUV? are the headlights aimed appreciably below level? Perhaps Germany uses a fixed height at fixed distance standard, which I think might be a better choice overall, but does have its downsides (allows lights on small cars to be aimed a lot higher).
Modern cars indeed have a very sharp, well-designed cutoff at the top of their beam patter. This makes correct vertical aiming very sensitive: aim just slightly too high and oncoming drivers get nearly the full output of your headlights; aim just a little too low and your vision range becomes noticeably limited. Older headlights, with much softer upper beam patterns, were far more forgiving.
The problem is bad enough that, on my 2022, I carry an 8mm wrench in the glovebox so I can adjust the headlight aim as needed. This is particularly important because the aim is sensitive enough that loading or unloading the back of the car changes the level stance enough to put the headlights noticeably out of aim.
Compounding this problem, it's very common for cars to have poorly-adjusted headlights from the factory, often too high. I think this is because the factory adjusts the lights for a combination of the rated loading and not getting complaints from new buyers (which is more likely when they are aimed too low). Additionally, at least in the US, the "correct" alignment of the headlights is defined by the position of the headlight themselves (the top cutoff should be level to the position of the bulb, is the simple version, although I think the more formal version specifies a measuring distance and slight upward tolerance). This means that tall vehicles like pickup trucks will blind oncoming drivers of shorter vehicles when properly adjusted---once again, this was a much more forgiving problem when the top of the light pattern was much softer, but has become extremely noticeable now that headlights emit their full output almost all the way to the top.
I understand that auto-leveling headlights and headlights with a cabin height adjustment are much more common in Europe. For whatever reason they're rare in the US, and I think it might be difficult to get them to comply with US regulations which I understand to be somewhat archaic on this topic. Auto-leveling is probably the best technical solution available.
How does it work on your German SUV? are the headlights aimed appreciably below level? Perhaps Germany uses a fixed height at fixed distance standard, which I think might be a better choice overall, but does have its downsides (allows lights on small cars to be aimed a lot higher).
It works very well- the cutoff is always below the bottom of the window even on small sports cars, yet it lights the road itself a long ways. When the back squats due to loading it up, hauling a trailer, or I go over a bump with the front wheels- the headlights always stay pointed down out of peoples eyes. My vehicle is 15 years old, newer German SUVs have dynamic beam shaping that detects cars and actively blocks the light in just the right spots.
Related to your other comments- I think taller vehicles should still have the lights themselves mounted low, and should angle downwards somewhat, not just forwards. It should not be legal to build or drive a car where the cutoff is high enough to blind people in normal cars.
Related to your other comments- I think taller vehicles should still have the lights themselves mounted low, and should angle downwards somewhat, not just forwards. It should not be legal to build or drive a car where the cutoff is high enough to blind people in normal cars.
[deleted]
How is it when you pull up behind me in my hatchback at a red-light?
From the factory, the high beam cutoff would still be below the bottom of your windows and mirrors, so it still wouldn't be bright to you at all.
Since I did lift my vehicle for offroad use, if your vehicle is unusually low and I pulled right up on your bumper it could still shine bright inside (but still below the rearview mirror level)- but I am quite aware of this, and never pull forward enough that the cutoff rises above the bottom of the car window in front of me. This is also just a good driving technique for me as well, because it leaves me enough room to escape the lane or drive around you if I need to in an emergency, e.g. due to a disabled vehicle, etc.
Since I did lift my vehicle for offroad use, if your vehicle is unusually low and I pulled right up on your bumper it could still shine bright inside (but still below the rearview mirror level)- but I am quite aware of this, and never pull forward enough that the cutoff rises above the bottom of the car window in front of me. This is also just a good driving technique for me as well, because it leaves me enough room to escape the lane or drive around you if I need to in an emergency, e.g. due to a disabled vehicle, etc.
> This is also just a good driving technique for me as well, because it leaves me enough room to escape the lane or drive around you if I need to in an emergency, e.g. due to a disabled vehicle, etc.
We were taught this in high school drivers-ed.
We were taught this in high school drivers-ed.
Nice. Then my only problem would be my side mirrors. They don't tilt or have a prism, so I'm boned there. But I can just move my head to the side until we get moving again.
It's not even that the US has bad optics in our headlights
Dealers are the ones responsible for making sure headlights are properly aligned before being sold so that the cut off is below the regulated height. This is, however, not at all enforced or incentivised. Which means that none does it and many headlights are aimed too high
Many people also replace standard or HID bulbs with cheap LED bulbs which are not designed for the original housing and that results in crazy high lumens spraying everywhere without a proper cutoff.
Police mask have no incentive to ticket for any of this and the end result is being blinded at night constantly by either mis aligned headlights or cheap super bright LED bulbs.
Dealers are the ones responsible for making sure headlights are properly aligned before being sold so that the cut off is below the regulated height. This is, however, not at all enforced or incentivised. Which means that none does it and many headlights are aimed too high
Many people also replace standard or HID bulbs with cheap LED bulbs which are not designed for the original housing and that results in crazy high lumens spraying everywhere without a proper cutoff.
Police mask have no incentive to ticket for any of this and the end result is being blinded at night constantly by either mis aligned headlights or cheap super bright LED bulbs.
> Police mask have no incentive to ticket for any of this
You used to get pulled over for running with high beams on in NYC. The usual reason for doing so was to hide a broken low beam head lamp and hope the cops didn't notice. Nowadays you can do whatever TF you want around here and no one seems to care.
You used to get pulled over for running with high beams on in NYC. The usual reason for doing so was to hide a broken low beam head lamp and hope the cops didn't notice. Nowadays you can do whatever TF you want around here and no one seems to care.
That is all true, but even if properly aligned, most new cars in the USA have awful headlights with no sharp cutoff line at the top, so there is no way to point them to light the road well while not blinding oncoming drivers.
Moreover, like I mentioned, quite a lot of European cars have systems to automatically align and even steer/shape the beams dynamically, and do not require that type of adjustment.
VW's "dynamic light assist" for example, actively detects oncoming vehicles and dynamically reshapes the lighting pattern to block most of the light going directly towards other vehicles, while still lighting everything else.
Moreover, like I mentioned, quite a lot of European cars have systems to automatically align and even steer/shape the beams dynamically, and do not require that type of adjustment.
VW's "dynamic light assist" for example, actively detects oncoming vehicles and dynamically reshapes the lighting pattern to block most of the light going directly towards other vehicles, while still lighting everything else.
You’ve nailed it. I miss my Audi with headlights that moved when I turned the wheel. That alone would fix a lot of the issues of being blinded when coming around a curve. A lot of US pickup trucks just have lights across the whole front end, and if you drive a car it’s just illuminating the whole inside of your car and every mirror.
I'm getting Gunnar computer glasses for night time driving. It's designed for the same problem in a different form: ever-bright LED monitors.
And that's the heart of the problem, really. LEDs are getting brighter everywhere. As thigs get brighter, our vision acclimates to the new brightness until it's not bright enough, which drives demand for brighter things, which we acclimate to, etc. ad nauseum.
As for me, I've switched to eInk panels for reading on the Internet (which is most of what I do) and use a red color filter at night or in dark spaces. I want to save my eyes for as long as possible!
And that's the heart of the problem, really. LEDs are getting brighter everywhere. As thigs get brighter, our vision acclimates to the new brightness until it's not bright enough, which drives demand for brighter things, which we acclimate to, etc. ad nauseum.
As for me, I've switched to eInk panels for reading on the Internet (which is most of what I do) and use a red color filter at night or in dark spaces. I want to save my eyes for as long as possible!
I've been using yellow night-driving clipons for my glasses for the last few years, and they help a lot, but they don't solve the whole problem. They do make it generally tolerable.
My solution is to minimize driving at night. Harder to do in the winter, but still doable especially if you work from home.
I used to always find it _easier_ to drive at night because cars would be like little Christmas lights, and the contrast between headlights & the darkness of night made them very easy to spot; now I'm blinded everywhere I go. Haven't ever contemplated window tints but at this point it feels like I either need to do that, or get a higher vehicle. Or just not drive at night :')
California basically sets the standards that all automakers follow for cars sold in the USA. If they can't sell a car in California that basically makes it impossible for them to make money.
California is so fond of regulating everything I hope they take this on. But whether it's California, or the Feds/DOT, someone needs to act. Headlight brightness is out of control.
California is so fond of regulating everything I hope they take this on. But whether it's California, or the Feds/DOT, someone needs to act. Headlight brightness is out of control.
This problem is a result of regulation, as it's not legal to have steerable headlights that solve its problem like folks do in Europe.
It is legal, though -- or at least, it has been legal for a couple of years.
https://www.nhtsa.gov/press-releases/nhtsa-allow-adaptive-dr...
https://www.nhtsa.gov/press-releases/nhtsa-allow-adaptive-dr...
Steerable headlights seem too complicated/expensive and just another thing to go wrong.
Just regulate the beam pattern and brightness with consideration given to modern LED lighting not 1980's incandescent bulbs.
Just regulate the beam pattern and brightness with consideration given to modern LED lighting not 1980's incandescent bulbs.
California emissions used to be a thing. California light emissions could be too.
No California Light Resources Board sticker on your headlights and you get a ticket. Give it at the same time as you get one for no front plate. Somehow cars are sold without front plate holders installed even though they're mandatory in California, too :P
But yeah, I'd welcome rules in California as a first step if the feds can't get it together.
No California Light Resources Board sticker on your headlights and you get a ticket. Give it at the same time as you get one for no front plate. Somehow cars are sold without front plate holders installed even though they're mandatory in California, too :P
But yeah, I'd welcome rules in California as a first step if the feds can't get it together.
Link from the article demonstrates the issue: https://www.youtube.com/watch?v=MkwjMV2of_8&t=697s .
Auto companies are violating the spirit of the regs while being technically compliant.
Auto companies are violating the spirit of the regs while being technically compliant.
The shift to unsafe high-blue lights is simply a matter of forgetting what was figured out. In the 20th century the lighting companies (GE, etc) had all the money in the world, and spent a lot on R&D. They figured out how to get the most efficient lights possible for their customers. The scientists figured out exactly how blue light causes inflammation in our eyes. There are good reasons why cities used orange High Pressure Sodium [HPS] Bulbs for street lights: HPS is very energy efficient (as good as most LEDs), and they emit light that is almost blue-free.
Then LEDs were invented by companies that didn't have that old R&D. The automotive industry gradually switched to LEDs for the advantage of not needing to replace bulbs (but lights that fail are now >$1000 to replace instead of $5)
Instead of putting safe low-blue LEDs on their cars (~2400K), auto manufacturers are using 4000K to 5000K LEDs. These have too much blue light.
To understand modern lighting, the term "spectral power distribution" is quite helpful: https://en.wikipedia.org/wiki/Spectral_power_distribution
Relative Spectral Power Distribution graphs show how much of each color of the rainbow is in a given source of light. Incandescent bulbs are mostly Red-orange-yellow light with a bit of green and even less blue. 5000K fluorescent or LED bulbs are mostly blue light with just enough red orange and yellow to trick people into thinking the light is 'white'.
I emailed Daniel Stern a few years ago and asked, essentially, 'why aren't auto manufacturers putting safe lights on their cars?' The essence of his reply was that the automotive engineers still know how to design safe headlights, but there were other considerations in play. I took this to mean that the marketing department told the engineers, "cars with safe headlights don't sell anymore, so you need to design headlights with blue-white LEDs." Daniel's response also helped me realize that the worst of the headlights on the road in 2017 were LED retrofits, where people bought LEDs to replace the halogen bulbs their vehicle's headlights were designed to use.
The shift to unsafe lights started in the 80's or 90's, when luxury brands started putting High Intensity Discharge lights on their vehicles. These lights have more blue light than the old incandescent and halogen headlights. Headlights with more blue became associated with more expensive cars, even though blue light is terrible for humans at night.
https://en.wikipedia.org/wiki/High-intensity_discharge_lamp
Daniel has a webpage about how France used to require yellow headlights: https://www.danielsternlighting.com/tech/lights/light_color/...
The rest of Europe didn't require yellow headlights, and there was a problem of having to put cadmium in the glass, so France got rid of their requirement.
I submitted an AskHN a few years ago, but it didn't get much traction: Ask HN: What prevents the automotive industry from using safe LEDs? - https://news.ycombinator.com/item?id=27334405
In 2020 I sat down to think about why blue light at night is so terrible, and sort of figured it out.
Then LEDs were invented by companies that didn't have that old R&D. The automotive industry gradually switched to LEDs for the advantage of not needing to replace bulbs (but lights that fail are now >$1000 to replace instead of $5)
Instead of putting safe low-blue LEDs on their cars (~2400K), auto manufacturers are using 4000K to 5000K LEDs. These have too much blue light.
To understand modern lighting, the term "spectral power distribution" is quite helpful: https://en.wikipedia.org/wiki/Spectral_power_distribution
Relative Spectral Power Distribution graphs show how much of each color of the rainbow is in a given source of light. Incandescent bulbs are mostly Red-orange-yellow light with a bit of green and even less blue. 5000K fluorescent or LED bulbs are mostly blue light with just enough red orange and yellow to trick people into thinking the light is 'white'.
I emailed Daniel Stern a few years ago and asked, essentially, 'why aren't auto manufacturers putting safe lights on their cars?' The essence of his reply was that the automotive engineers still know how to design safe headlights, but there were other considerations in play. I took this to mean that the marketing department told the engineers, "cars with safe headlights don't sell anymore, so you need to design headlights with blue-white LEDs." Daniel's response also helped me realize that the worst of the headlights on the road in 2017 were LED retrofits, where people bought LEDs to replace the halogen bulbs their vehicle's headlights were designed to use.
The shift to unsafe lights started in the 80's or 90's, when luxury brands started putting High Intensity Discharge lights on their vehicles. These lights have more blue light than the old incandescent and halogen headlights. Headlights with more blue became associated with more expensive cars, even though blue light is terrible for humans at night.
https://en.wikipedia.org/wiki/High-intensity_discharge_lamp
Daniel has a webpage about how France used to require yellow headlights: https://www.danielsternlighting.com/tech/lights/light_color/...
The rest of Europe didn't require yellow headlights, and there was a problem of having to put cadmium in the glass, so France got rid of their requirement.
I submitted an AskHN a few years ago, but it didn't get much traction: Ask HN: What prevents the automotive industry from using safe LEDs? - https://news.ycombinator.com/item?id=27334405
In 2020 I sat down to think about why blue light at night is so terrible, and sort of figured it out.
There are a couple of main issues:
1) is that some bulbs can be inserted into the holder two orientations, but only one is correct as there is often a shield stopping light bleeding up.
2) is that some lights appear to be almost horizontal rather than aimed down, if you're driving a smaller car you have lights almost aimed right at you - we need to tax cars based on size as well as emissions.
1) is that some bulbs can be inserted into the holder two orientations, but only one is correct as there is often a shield stopping light bleeding up.
2) is that some lights appear to be almost horizontal rather than aimed down, if you're driving a smaller car you have lights almost aimed right at you - we need to tax cars based on size as well as emissions.
https://news.ycombinator.com/item?id=42332314
(12 points, 5 comments)
(12 points, 5 comments)
I’m in the UK and there’s been an increase in the number of people driving with actual full blown full beam headlights on.
Hm I find the opposite. Often following a vehicle at night they're extremely shy about using full beam. Totally oblivious. I live near lots of rural, pitch black A roads and it's really needed
I would also like to add that the dazzling lights make it impossible to see the tiny indicators modern cars have
It took thousands of words to get to alignment. That's the key. Switzerland has strict vehicle safety inspections, including an automated alignment test, and we don't have glare problems that I've noticed.
Can we get the same thing applied to bike headlights? At night it is easier to bike on the road than the bike trail because almost every bike headlight is in effectively high beam mode all the time and are powered by outrageously bright LEDs. Sometimes they even have an epileptic detecting strobe mode.
Personally, I'm not sold on the safety benefits of blinding and dazzling all oncoming traffic.
Personally, I'm not sold on the safety benefits of blinding and dazzling all oncoming traffic.
These cyclists unfortunately need to just point their headlight downward--included in the installation instructions for almost all bike headlights is the direction to point the light below horizontal. That is also the only difference between automotive high and low-beams: the angle at which they are directed.
You would think that, but most bike headlights are just throwing as much light as possible in a 180 degree arc so the rider can spot drop bears and other related hazards. It is so rare for someone to have a light that directs the photons downward like an automotive headlight. When I was looking for a headlight my local bike shop didn't sell a single model that had that feature, in fact they made a big deal about having 180 degrees of illumination and 1000 lumen output and an oncoming traffic blinding strobe mode. Also, the bike shop stock was hilariously overpriced for what it was. $5 of flashlight components in a plastic case and they wanted $80. It felt like the entire industry was being grossly overcharged and underserved.
I had to construct my own headlight out of a flashlight and a homemade deflector.
For example:
https://www.planetbike.com/products/beamer-700-bike-headligh...
I had to construct my own headlight out of a flashlight and a homemade deflector.
For example:
https://www.planetbike.com/products/beamer-700-bike-headligh...
The shape of the beam is important, not just the angle of it. Part of what differentiates a low-beam headlamp from a high-beam headlamp is the shape of the beam.
Bike lights, at least as-sold here in the States, seem to generally be built from flashlight parts. And unlike car low beams, flashlights project a circular beam.
With a circular beam, it is really hard to illuminate the path ahead with any meaningful brightness without blinding others.
A better beam pattern, ideally with sharp cutoffs, can illuminate a pathway and the obstacles that may be on it without unduly blinding others.
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I happened to buy one such light, just by chance, several years ago. It's a "Schwinn Intensa 100" from Wal-Mart, part number SW80251WM. It kind of sucks in terms of overall illumination and is no good for high-speed rides at night, but it does light up the path ahead and provides a sharp beam cutoff to avoid blinding others. (So actually, it's pretty excellent for casual riding.)
Bike lights, at least as-sold here in the States, seem to generally be built from flashlight parts. And unlike car low beams, flashlights project a circular beam.
With a circular beam, it is really hard to illuminate the path ahead with any meaningful brightness without blinding others.
A better beam pattern, ideally with sharp cutoffs, can illuminate a pathway and the obstacles that may be on it without unduly blinding others.
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I happened to buy one such light, just by chance, several years ago. It's a "Schwinn Intensa 100" from Wal-Mart, part number SW80251WM. It kind of sucks in terms of overall illumination and is no good for high-speed rides at night, but it does light up the path ahead and provides a sharp beam cutoff to avoid blinding others. (So actually, it's pretty excellent for casual riding.)
> These cyclists unfortunately need to just point their headlight downward […]
On well-lit urban streets, you probably don't need more than ~500 lumens, as the road is already illuminated and the light is mostly about other people seeing you.
Also, having it flash in a consistent manner (and not some kind of "random" cycle) is best, as it's easier to track a simple on-off pattern with a deterministic frequency.
(If you're riding on non-lit roads or trails, then certainly more lumens and further throw is useful.)
On well-lit urban streets, you probably don't need more than ~500 lumens, as the road is already illuminated and the light is mostly about other people seeing you.
Also, having it flash in a consistent manner (and not some kind of "random" cycle) is best, as it's easier to track a simple on-off pattern with a deterministic frequency.
(If you're riding on non-lit roads or trails, then certainly more lumens and further throw is useful.)
Buy bicycle lights designed to meet EU and or the proper German / French regulations and they will have a cut off
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SAE standards are there so North American manufacturers can cheap out.
Ultra bright vs fully tinted windows (front included). These are the days I feel greatest my German heritage.
I always wondered if polarization could be a solution to the problem.
Polarising headlights and adding a filter to the windshield.
Polarising headlights and adding a filter to the windshield.
Wouldn't the filter also end up dimming the things you are trying to see?
Wow... Fuck cyclists and other road users, I guess!
To all windshields?
I have a degenerative eye disease. As one of its features is loss of visual acuity, my driving days are numbered. When they come to an end, I'll likely have to move, as it's just not possible to efficiently or affordably get around in environments other than urban when you're blind.
Another feature of my condition is extreme light sensitivity, and difficulties with contrast. I generally need a lot of it, but at the same time, bright light washes out everything around it, blinding me. That feature seems to be progressing more rapidly than the loss of acuity in my case. Consequently, the extreme brightness of headlights nowadays is likely to cut my night driving still shorter, perhaps by years.
If you're not facing such a prospect yourself, it can be difficult to appreciate what a loss of freedom and ease it is to give up driving. It sucks bad.
I hope these overbright headlight haters continue to gain traction!
Another feature of my condition is extreme light sensitivity, and difficulties with contrast. I generally need a lot of it, but at the same time, bright light washes out everything around it, blinding me. That feature seems to be progressing more rapidly than the loss of acuity in my case. Consequently, the extreme brightness of headlights nowadays is likely to cut my night driving still shorter, perhaps by years.
If you're not facing such a prospect yourself, it can be difficult to appreciate what a loss of freedom and ease it is to give up driving. It sucks bad.
I hope these overbright headlight haters continue to gain traction!
Cataracts are commonplace in older drivers. Until the operation is done driving at night can get you dazzled. But if you get the fancy multifocal lenses, you will get halos.
That's a good point! Overly bright headlights are a problem for a lot of kinds of eyes, including some we should expect to see more than a few of on the road.
(I will say for myself that my contact lenses have long been thick enough to cause the same kind of halos, and I also have mild astigmatism, so I'm used to seeing those symmetrical light patterns smearing over everything. Those cam be distracting for sure, but the light sensitivity issues I have are more like the moment you step directly out of a dark movie theater into the sunlight on a clear, bright day— visual information just disappears in the face of overwhelming brightness so that things are washed out, and there is often pain. In my experience, halos are more like overlays on the visual field and astigmatism artifacts are sparser with longer radius (not covering the whole range of angles surrounding the light source but jutting out vary far in long, stretched spearheads rotating almost kaleidoscopically).
(I will say for myself that my contact lenses have long been thick enough to cause the same kind of halos, and I also have mild astigmatism, so I'm used to seeing those symmetrical light patterns smearing over everything. Those cam be distracting for sure, but the light sensitivity issues I have are more like the moment you step directly out of a dark movie theater into the sunlight on a clear, bright day— visual information just disappears in the face of overwhelming brightness so that things are washed out, and there is often pain. In my experience, halos are more like overlays on the visual field and astigmatism artifacts are sparser with longer radius (not covering the whole range of angles surrounding the light source but jutting out vary far in long, stretched spearheads rotating almost kaleidoscopically).
Oh God yes please someone do something about this.
The most compelling issue to me came at the end of the piece, but it is much deeper and harder to address: the increasing lack of civility and anti-collectivist tendencies in American life.
Whover wants to oppose these kind of headlights, and SUVs, will have my vote.
Is your comment about SUVs simple because you notice this issue is more prevalent in taller cars or because you don’t like them for other reasons? I myself have not noticed this correlation. Some of the time it’s after market crap the owner didn’t bother to adjust properly, but most of the time it’s newer cars such as Teslas where see this issue , and the sedans are fairly low to the ground
With taller vehicles the headlights often start out higher off the ground. Even if aimed properly, that puts oncoming drivers in a brighter portion of the light as the distance closes.
Taller cars with higher lights definitely cause more of a problem for other drivers, simply due to the geometry involved.
I have a sedan, when another sedan pulls up behind me I don't see their lights. When a tall vehicle pulls up behind me, their lights shine directly through my rear window, reflect directly from the rearview mirror, and cause glare on my windshield. Incredibly frustrating.
I have a sedan, when another sedan pulls up behind me I don't see their lights. When a tall vehicle pulls up behind me, their lights shine directly through my rear window, reflect directly from the rearview mirror, and cause glare on my windshield. Incredibly frustrating.
Cars with a taller front end are more noticeable and I also hate SUVs. There's no need to move a 2000kg monster vehicle around, they use a lot of space and pollute a lot.
Is there any similar campaign to have something done about loud vehicles?
New York has implemented automated tickets for loud vehicles:
https://www.roadandtrack.com/news/a39105913/new-york-automat...
I'd like to see a version for headlights, but the logistics would be tricky. It's common in my area for people to lift their trucks, and they rarely readjust their headlights afterwards.
https://www.roadandtrack.com/news/a39105913/new-york-automat...
I'd like to see a version for headlights, but the logistics would be tricky. It's common in my area for people to lift their trucks, and they rarely readjust their headlights afterwards.
Every vehicle in (most?) states have to already be checked regularly for things like emissions. There's no reason we couldn't check for improper lights as part of that.
Emissions inspections are being sunset in more places. Even where they're alive and well, it's gone from an active check with a tailpipe detector and a dynamometer to just plugging into the ODB-II and a visual inspection for unauthorized emission modifications. maybe a check for smoke in neutral when going from idle to full throttle and back.
Americans don't want their cars inspected, so a new inspection criteria is unlikely. For those subject to mandatory safety inspections, it might already be part of the test.
Americans don't want their cars inspected, so a new inspection criteria is unlikely. For those subject to mandatory safety inspections, it might already be part of the test.
I'm all in for freedom, but this is kinda crazy.
Some states do check for headlight alignment.
I am similarly irritated by loud vehicles and wonder why they are allowed to persist. Would this be better enforced if it didn't rely 100% on officer testimony? I wonder if there is a market for a "sound camera" that could be marketed to police departments. The idea would be that you point this thing at cars, like their radar gun, and it captures video, sound, and the # of decibels. Only thing I don't know is if there is a way to attribute particular sounds to particular objects found in the video. This would, potentially, give them the hard evidence to ticket these cases. If there is an easy way to make money off these, the police would be sure to enforce it.
I'm always amazed at how loud passenger pickup trucks are by default here in the US - growing up in Canada, pickup trucks were generally quiet / unobtrusive unless user modified. Here, they seem to come LOUD from the factory - probably less regulations, and it's cheaper to have a loud muffler and/or get a few more hp/lb-ft for the towing wars.
And because the clientele who buy trucks generally WANT something that sounds loud and powerful. Not saying that's good or bad, just how it is.
> Is there any similar campaign to have something done about loud vehicles?
There are already US regulations on car noise,[0] and in more general circumstances,[1][2] but once it's purchased it can be altered by the owner, and then it's often up to local authorities to enforce local (and state[3]) noise by-laws.
[0] https://www.law.cornell.edu/cfr/text/49/325.7
[1] https://en.wikipedia.org/wiki/Noise_Control_Act
[2] https://en.wikipedia.org/wiki/Noise_regulation
[3] https://www.semasan.com/resources/exhaust-noise-laws-state
There are already US regulations on car noise,[0] and in more general circumstances,[1][2] but once it's purchased it can be altered by the owner, and then it's often up to local authorities to enforce local (and state[3]) noise by-laws.
[0] https://www.law.cornell.edu/cfr/text/49/325.7
[1] https://en.wikipedia.org/wiki/Noise_Control_Act
[2] https://en.wikipedia.org/wiki/Noise_regulation
[3] https://www.semasan.com/resources/exhaust-noise-laws-state
Yes, in the Netherlands, NYC and elsewhere: https://www.roadandtrack.com/news/a60583398/nyc-noise-camera...
I hope so. It's a "war" that I can get behind. Nothing more annoying than some insecure loser revving his engine while driving by your house. It's both noise and air pollution. Should be banned outright.
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That's a war thats being won by EVs.
There are EV's that have gotten tickets for being too loud: https://www.thedrive.com/news/hyundai-steps-in-to-help-elant...
The Elantra N is not electric.
That’s a link to a standard gas vehicle being ticketed.
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multimoon(2)
safety! Safety!! SAFETY !!!
brighter is safer, you loose:)
there has been another insane thing ,where the lights in schools have gotten impossibly bright, and school bussses have strobes on top that can be seen 50 miles away.
Its guaranteed that there are saftey comitties trying to legeslate much more extream measures
Used to like cars at one point but nowadays I find that my only (okay, only _daily_) grievances in life are noise from cars & driving at night in rich areas, both of which have soured my views on cars.