Thursday, 3 December 2009

Car Headlights

Using LED lamps as stop- and signal lights on cars seems like a great idea - giving more colour than light, while using practically no energy, is what diodes do best!

But replacing the standard warm-white top quality halogen light commonly used for headlights is not such a great idea.

Since their introduction in early 1990's, more and more cars are now being equipped with mini discharge Xenon arc headlight lamps. They're about twice as bright as halogen headlights or more, and are said to improve visibility for the driver. But what few seem to have considered is how irritating they can be for meeting traffic:

- They're blueish (around 4100K), which creates more confusion and distraction in an otherwise even traffic stream. Lights from meeting cars are not supposed to attract your attention by sticking out. And blue light is not good for the eyes.

- An especially irritating feature is that they flicker and quickly shift shade from blue-white to purple-white and back as the car drives past, instead of giving a calm, even light like halogen does. This can be very distracting, especially when you meet one at a turn.

- They're very bright and glaring. That's not good for the eyes either. Or for road safety. Being blinded and distracted in crucial traffic situations is not exactly helpful.

The Swedish Road Administration say they keep getting complaints from other drivers but can’t do anything about it since these lamps tend to get approved by EU as car manufacturers apply. A condition for this approval is that they must be precisely adjusted so as to avoid glare for others, but this is obviously not always done, or is easily maladjusted again depending on packing weight etc.  

- Getting a xenon-lit car driving behind can be even worse than briefly meeting one, especially if it's a van or SUV where the headlights come up higher. Having the inside of one's car lit up like a stadium does not make for safe driving. And this goes for trucks, vans and SUVs equipped with standard halogen lights as well. 

If you're considering switching to xenon, please be mindful of other drivers and consider staying with traditional halogen if possible. If you the car is already equipped with xenon, please make sure lights are well adjusted at all times.

Also beware of Faux Xenon, e.g. Osram's Cool Blue - "the designer lamp" - a product that shouldn't exist. Putting a blue filter on a standard halogen bulb is about the stupidest thing you can do. These should definitely be banned, as they are both energy inefficient and dangerous!

Nowadays headlights in general are also much brighter than they used to be - manufacturers constantly boast about how much more light their product will give you:

* Osram Silverstar "Thanks to their special technology SILVERSTAR lamps illuminate the road with an up to 50% brighter light in the crucial zone 50 to 75 m in front of the vehicle than a standard lamp"
...and in the crucial vision zone of meeting traffic, pedestrians and bicyclists.

* Philips X-treme Power "Philips X-treme Power bulbs deliver up to an astounding 80% more light than standard halogens"
...right into the unsuspecting eye of everyone but the driver.

If the European Commission ever wanted to do anything truly useful, why not ban xenon lights as a safety hazard, faux xenon as a waste and hazard both, and set firm limits to how bright headlights can be?


  1. i'm so glad i found your blog! so much information! (i'm yet to read it all...) what a relief to find a clear-headed person speaking out about the myths of lighting and energy. hap-pyyyy!!!