LEDs conquer headlights

Both LEDs will be qualified according to automotive standard AEC-Q101 and easily achieve the brightness level of halogen lamps.
....
The two models have a high colour temperature of 5600 K that is closer to natural daylight than other headlight sources. In particular this improves visibility at the edges of the illuminated zone because the human eye is better at perceiving objects in day-light white light than in other light colours. The LEDs provide concentrated light from a small surface area and are therefore ideal for use in headlights.
http://www.osram-os.com/download_protected/press/rtf/PR_OSTAR_Headlamp.rtf


Pictures of the module here:
http://www.osram-os.com/download_protected/press/tif/300dpi_PR_electronica_booth_concept.zip

It looks like five dies and
"For a typical forward current of 700 mA the OSTAR Headlamp achieves 250 lm"

So probably we are looking at needing 12 Watts in the OSRAM "super LED headlamp". 250lumens/12 Watts = 20.83 lm/W

I guess, in a car, you can afford the losses, the heat, and heatsinking requirements.

Over a year ago, I read in Automotive Engineering magazine that they claimed to make the lumens they wanted from LED headlights, just that heat sinking was a problem. I guess increased efficiencies got rid of that problem.

Not so sure about some of their claims though. LED narrow band color is probably still not as good as incans.
There was a study done by the French just prior to the formation of the European Union that found YELLOWish color was clearly better for headlights than whiter colors, and WAAAY better than Blue-ish HID or tinted HID-look Halogen.
The "Way-Warm" color has the same benefits we attribute to incans vrs. LED, or even warmer tinted LEDs vrs. very white LEDs.
Even more, it has less glare to oncoming cars and pedestrians, and cuts through fog better. But wait! everybody already knew about fog cutting because FOG lights used to be yellow or amber. The white "fog" lights on cars today are there just for looks. It seems they are only aimed at increasing glare.
Regrettably, when the EU formed, the French study was tossed in favor of uniform EU automotive codes. This was even lamented in an article in an automotive magazine at the time.
In my opinion there should be a Maximum set on automotive headlight color temp of less than 3500K, a little above indoor tungsten. Daylight is 5500K by the way, so Osram overshot a little.

Also, point source light is only good from an automotive design standpoint for packaging the light in a swoopy designed car. Larger area headlights are better for oncoming glare - an ever increasing problem that is ever increasingly ignored as people are distracted from their driving more by their phones.

End Rant

I still don't get it. What do people like about these Osram LEDs? Look at that efficacy, it's just very very poor...

Marketing.

True, they're not as efficient, but you DO get a lot of light from a (relatively) single source (for reflectors) rather than messing with attempting to focus an array. Efficiency or not.

It's probably easier to focus an array than use a large reflector. You can use an aspherical lens to focus a power LED that's fairly forward projecting (like a cree or Nichia). It takes less space, focuses better, and is more flexible with design (4-5 LEDs + lenses per headlight can be arranged in a variety of ways) Sticking with the projector/reflector headlight paradigm is no longer necessary.

Hmmm what an interesting concept!

Cool info.

Yes the OSTAR isn't the most efficient LED, Its beaten by the XR-e but Its better than K2s though. The do make a lot of light from a single unit. The multi die characteristic sems better to me for a car headlamp do to their floody nature. How many car head lights use a narrow spot beam. This is the reason I am interested in them for a mountain bike light. I tested one of the 2 I bought in the recent group buy today at 1 amp. I don't have proper reflector yet but plonked a k2 type on....at isn't on properly, but it still had the best amount of light I have seen of any single LED, and it wasn't that far off my 10W HID in both brightness and flood. It is also whiter than the HIDs blue. I have modified a cateye which had 2 lux 3s, I put a couple of K2s in there. I also have a stock cateye triple with its original 3s, neither are as good as the HID. The OSTAR is very close in undeal circumstances. 2 running at 350mA would be sweet for efficiency and brightness.

It will be interesting comparing them to the XR-E Q2s I have on order.

Stu

I don't want bright headlights. I want headlights that don't blind everyone going down the street and let me see the street. We need a new way of doing this. Blinding everyone is not the answer.

Maybe the people in the cannonball picture had the right idea????

Stuart B said:

Cool info.
It will be interesting comparing them to the XR-E Q2s I have on order.

Stu

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Looking forward to your comparison, I'm very curious to see how well (or bad?) this $70 Led performs against the recent XR-Es. Thanks.

North American manufacturers are targeting more in the 4,000 to 4,500 degree color temperature range which does improve vision compared to 3K, but does not create the glare of 6K. Newer HIDs for cars are moving away from the stark blue that was the norm initially. We also have the issue that HIDS are just plain brighter, and when you take into account scotopic vision, much brighter.

Semiman

dabiscake said:

Looking forward to your comparison, I'm very curious to see how well (or bad?) this $70 Led performs against the recent XR-Es. Thanks.

Click to expand...

I will have to get around to drilling and tapping some holes in an old cpu heatsink so I can mount everything without me having to hold it all hehe. I'll try and take some piccies back to back too once I have.

I think both LEDs are good but for different reasons. The OSTAR seems to be the supercar....high performance but less frugal. The Cree is efficient, if you have room for many, then they are the better bet. As with cars it's a trade off between brightness from one package and efficiency.

To comapre to HID I need horsepower....and perferably with as few engines as possible....to a point. I won't be running them at 20W though (On a bike light at least)....I can't be arsed to carry that many batteries hehe. To compare to HID I think I'd need 4 Crees (For a bar light it isn't that rediculous though...about 45mm square from the front).

There do sem to be some OSTAR bashers. The only thing that I wince at is the price. The Crees is less than half the cost but is better than half as good overall (Does that even make sense lol)

A car headlamp has plenty of room for Crees though.

Stu

ken2400 said:

I don't want bright headlights. I want headlights that don't blind everyone going down the street and let me see the street. We need a new way of doing this. Blinding everyone is not the answer.

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Yes, I don't see why cars can't just have a bar of lights across the front. Combined they would put more light on the street yet each emitter wouldn't be as blinding. The idea of having 2 or 4 discrete headlights is a throwback to incandescents. With an entire LED headlight assembly being much thinner you can just put a row of lights right across the whole front end. As a bonus it'll light the street much more evenly.

SemiMan said:

North American manufacturers are targeting more in the 4,000 to 4,500 degree color temperature range which does improve vision compared to 3K, but does not create the glare of 6K. Newer HIDs for cars are moving away from the stark blue that was the norm initially. We also have the issue that HIDS are just plain brighter, and when you take into account scotopic vision, much brighter.

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Exactly. Lower color temperature lighting, besides being unfavorable to scotopic vision, also results in the so-called "tunnel effect" where your peripheral vision is greatly diminished. The effect is worst for sodium vapor but still exists for regular halogen lights. 4000K to 4500K eliminates this effect, and also looks more aesthetically pleasing (they blend in with starlight/moonlight rather than clashing with it as halogen does). For similar reasons the next generation of streetlights will most like be of similar color temperature and without any color tint. The days of amber sodium vapor are certainly numbered for safety if not for aesthetic reasons.

jtr1962 said:

Yes, I don't see why cars can't just have a bar of lights across the front. Combined they would put more light on the street yet each emitter wouldn't be as blinding. The idea of having 2 or 4 discrete headlights is a throwback to incandescents. With an entire LED headlight assembly being much thinner you can just put a row of lights right across the whole front end. As a bonus it'll light the street much more evenly.

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I totally agree with the strip of light idea. It seems clearly superior. It would define where your car is better than the present system. I was quite disapointed when I found out that Mercuries don't have a headlight all the way across the front. They have a headlight on either side and the middle lights are just dummies. 8-(