Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

BMW's Laser Headlights

wot.motortrend.com

Post reply on HN
Print view View original

41–50 of 77 posts

Re: BMW's Laser Headlights

#41

Post by Cairn »

MBCook wrote: post #21
brokentone wrote: post #18

Bear with me here-- I understand lasers to be highly specific wavelength diode light that is bounced around in a combination of prisms and mirrors to create highly concentrated, highly directional light. In this case, it's then diffused again through a yellow phosphorus lens. I'm not doubting the numbers in efficiency gain, but I'm having a hard time figuring them out. Seems that there can only be loss from convertin…

Well, let's assume these lasers are 10x as efficient as LEDs used in headlights. Even if you lost 70% of the light in the process of exciting phosphorus, you'd still have a net gain. My question would be: are modern headlights really that much of a drain?

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

Re: BMW's Laser Headlights

#42

Post by fsckin »

auctiontheory wrote: post #36
StavrosK wrote: post #17

Earlier quoted context omitted.

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

I never see anyone being bothered by them at all. WTF. How on earth would you know whether drivers going in the opposite direction were being blinded by your lights?!

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

Re: BMW's Laser Headlights

#43

Post by CraigJPerry »

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

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

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

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

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

Re: BMW's Laser Headlights

#44

Post by Cairn »

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

Re: BMW's Laser Headlights

#45

Post by streetnigga »

rhizome wrote: post #3
christoph wrote: post #2

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

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

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

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

Re: BMW's Laser Headlights

#46

Post by streetnigga »

StavrosK wrote: post #17
blahedo wrote: post #15

Earlier quoted context omitted.

Xenon lights are obnoxious because they are so much bluer than standard lights, they are that much more blinding; outdoor lights that are too blue (or full-spectrum) have the paradoxical effect of making everything darker by contrast, and much harder to see. I can't stand cars that have xenon lights, and I was glad to see their numbers start to decline in the last couple years.

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

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

Re: BMW's Laser Headlights

#47

Post by anon4 »

christoph wrote: post #2

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

Why not just wear sunglasses?

Re: BMW's Laser Headlights

#48

Post by masklinn »

retrogradeorbit wrote: post #26
lovemenot wrote: post #24

Earlier quoted context omitted.

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

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

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

Re: BMW's Laser Headlights

#49

Post by yread »

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