Wondering About The "Notch" In Your Headlamp Pattern?

[ldusseau]

If anyone is wondering what the "notch" is (dark spot) is along the low beam cut off, you can blame IIHS. A few years ago IIHS (Insurance Institute for Highway Safety) published their independent headlamp ratings and dinged basically every OEM for "poor" headlamps. The set up their own rating system with test points on a road (points in the headlamp beam pattern where illumination requirements must be met) and OEMs scrambled to meet it lest the get any more bad publicity (BMW was rated the worst and I can attest to that, I used to drive one). They made their headlamps brighter but in the process they went too far. SAE test points have maximum values as well, going over the lumen requirements dings OEMs for oncoming glare. It was the worst with trucks because the headlamps are so much higher than passenger cars, drivers were getting blinded. So the OEMs put a notch in the cut off to miss ONE test point and great, headlamps were passing. However some OEMs hated the look of the notch, so lighting suppliers had to react yet again by filling in the notch with light so it isn't as dramatic. IIHS ratings also explains why you see so many truck headlamps that are "divided" up with the DRL separate high in the vehicle and the low beams lower in the front fascia. Don't get me wrong, IIHS does great work to make vehicles safer by pushing OEMs to go above and beyond NHTSA standards specifically for crash ratings. However with the headlamps I think they overstepped their bounds, driving OEM and supplier engineers nuts with the shifting expectations.

 

[vipeboy2000]

So much of this could be helped if the us laws modernized to allow for matrix headlights.. I'm on the fence about iihs overstepping.. on one hand I'm glad because some new car headlights really were so poor and some are great but literally blind everyone else.. someone had to step in to create a little more level paying field.. but then we end up with notches or strangely summer l aimed lights.. but there isn't much more that can be done without moving to matrix headlights in my opinion.. initially obviously it will be significantly expensive but as it becomes more mainstream it will be like any other safety feature that becomes standard on trims like how aeb, bcw, lane keep etc has gone from being in luxury cars or top trims only to becoming standard on a few short years .

 

[ldusseau]

So much of this could be helped if the us laws modernized to allow for matrix headlights.. I'm on the fence about iihs overstepping.. on one hand I'm glad because some new car headlights really were so poor and some are great but literally blind everyone else.. someone had to step in to create a little more level paying field.. but then we end up with notches or strangely summer l aimed lights.. but there isn't much more that can be done without moving to matrix headlights in my opinion.. initially obviously it will be significantly expensive but as it becomes more mainstream it will be like any other safety feature that becomes standard on trims like how AEB (Autonomous Emergency Braking), bcw, lane keep etc has gone from being in luxury cars or top trims only to becoming standard on a few short years .

You sound like you know your lamps! You a lighting engineer too?

Agree but I still hold that IIHS didn't understand the full consequences of their rating system. I also agree on your point about matrixed LEDs. High beam assist helps somewhat, but my first experience with it Wednesday night was that it was of limited use because the high beams kept shutting off. If "anti glare" is ever approved by the government (it's been in use in Europe for years), matrixed LEDs are the way to go AND they are quieter than a shutter system.

 

[87and66]

Huh. Always wondered what was up with that. Thanks for the info!

 

[vipeboy2000]

You sound like you know your lamps! You a lighting engineer too?

Agree but I still hold that IIHS didn't understand the full consequences of their rating system. I also agree on your point about matrixed LEDs. High beam assist helps somewhat, but my first experience with it Wednesday night was that it was of limited use because the high beams kept shutting off. If "anti glare" is ever approved by the government (it's been in use in Europe for years), matrixed LEDs are the way to go AND they are quieter than a shutter system.

haha no, just a lighting geek... well, really ALL technology nerd, work in IT etc just like following all the new tech. I always thought it would be cool to work on the the light projection though. It really makes me wonder how some headlights ever made it out of qa...

 

[ldusseau]

Huh. Always wondered what was up with that. Thanks for the info!

You are welcome!

haha no, just a lighting geek... well, really ALL technology nerd, work in IT etc just like following all the new tech. I always thought it would be cool to work on the the light projection though. It really makes me wonder how some headlights ever made it out of qa...

it is really hard. the old reflector/halogen bulb systems were the worst with one focal point that is subjected to a LOT of manufacturing variation. You have your perfect optics prescription in the "computer" world, then it's machined into the tool (add variation), then it's molded out of thermoplastic (more variation), then assembled at the supplier (still more variation) then finally onto the car (more variation). This is why lighting suppliers have to be so far "over margin" in the beam pattern because you lose so much in the assembly process.

 

[vipeboy2000]

You sound like you know your lamps! You a lighting engineer too?

Agree but I still hold that IIHS didn't understand the full consequences of their rating system. I also agree on your point about matrixed LEDs. High beam assist helps somewhat, but my first experience with it Wednesday night was that it was of limited use because the high beams kept shutting off. If "anti glare" is ever approved by the government (it's been in use in Europe for years), matrixed LEDs are the way to go AND they are quieter than a shutter system.

Where does canada stand on smart headlights?

 

[vipeboy2000]

You are welcome!

it is really hard. the old reflector/halogen bulb systems were the worst with one focal point that is subjected to a LOT of manufacturing variation. You have your perfect optics prescription in the "computer" world, then it's machined into the tool (add variation), then it's molded out of thermoplastic (more variation), then assembled at the supplier (still more variation) then finally onto the car (more variation). This is why lighting suppliers have to be so far "over margin" in the beam pattern because you lose so much in the assembly process.

ah makes sense... It always amazes me whenever i see a car with OEM projector style headlights with a worse beam pattern than some reflector style headlights..

 

[chad1064]

If anyone is wondering what the "notch" is (dark spot) is along the low beam cut off,

Can you post a picture showing exactly what you are talking about? I'm curious but don't know what I'm looking for when looking at my headlight assembly.

 

[djerickd]

Can we take a dremmel to that notch lol

 

[vipeboy2000]

Can you post a picture showing exactly what you are talking about? I'm curious but don't know what I'm looking for when looking at my headlight assembly.

it's really visible if you pull up on to a wall at night with lights on.. but here's a pic i found on the interwebs of it from someone else. You can't really see the "notch" in the headlight unless you were to take it apart

 

[chad1064]

it's really visible if you pull up on to a wall at night with lights on..

Ahh, thank you! Yes, not going to see the notch by looking into my headlight assembly, lol. But I totally know what "the notch" means now. I've noticed this on the couple of night drives I've taken so far.

 

[JSolo]

Can someone define (pic?) what a matrix led is and how it's different from a non matrix?

 

[vipeboy2000]

Can someone define (pic?) what a matrix led is and how it's different from a non matrix?

audi isn't the only one in the game but here is a nice video about how it works. basically it can blank out where it sees where another car is to keep f rom blinding them while giving you the benfits of brights

 

[ldusseau]

Where does canada stand on smart headlights?

Canada is usually in lockstep with the US. However Canada was first to mandate DRLs so "we" played catch up. I used to work for Valeo and was releasing a Ford headlamp for multiple markets before alignment of North American standards (US/Canada) and it was a challenge.

 

[ldusseau]

audi isn't the only one in the game but here is a nice video about how it works. basically it can blank out where it sees where another car is to keep f rom blinding them while giving you the benfits of brights

In the LED matrix, sensors turn discrete LEDs off and on to get the dark spot. In projector LED/HID lamps there is a shutter that swivels back and forth to block the light in the beam pattern. There is a moveable shutter in most projector lamps that creates the low beam cut off. On high beam it swivels down out of the way. So the "notch" is actually a small raised area on the top of the lower beam shut off.

 

[ldusseau]

it's really visible if you pull up on to a wall at night with lights on.. but here's a pic i found on the interwebs of it from someone else. You can't really see the "notch" in the headlight unless you were to take it apart View attachment 63841

 

[Deviate]

I cant stand that spot. It took me a bit to not stare at it in corners, not turning in somewhere but around tight curves. It just creates a "blind" spot to me. Thanks for the info on it

 

[JSolo]

We really need some good aftermarket driving or fog lights for this car.

 

[Alphazone]

Isn't the notch the same thing as the cutoff from a HID headlamp or does it serve a different purpose in this specific situation? I never really payed attention to the notch in the headlight beam pattern but did kinda wish for a slope cutoff from the beam pattern instead of something so drastic looking.


edit: nvm, after sipping some coffee I understand now, so the main point of that notch is to avoid a hotspot and getting docked points from the IIHS. So it doesn't help keep the lights leveled properly like an actual cutoff..