Quick question guys: the auto levelling works every now and then when it detects more weight etc. but I still get high-beamed in the nights. Is there a setting to ensure the auto levelling does the 'up down up' check each time the head lights are turned on?
In real terms, a typical D3S gas discharge bulb (3200 lumen) emits more than twice as much visible light as a typical H7 halogen bulb (1500 lumen).
A standard gas discharge bulb has a nominal colour temperature of 4100 K, which increases as the bulb ages. Due to the way the human eye perceives visible light, we are more sensitive to the blue spectrum than the red spectrum. It is why we perceive a white light to be brighter than a yellow light, even if both bulbs objectively have the same lumen output.
For comparison, a standard halogen bulb has a colour temperature of 3200 K.
Irrespective of the bulb type used, the headlamps of any vehicle has the potential to blind oncoming drivers under certain circumstances, even if adjusted and calibrated as per the regulations and manufacturer's specifications.
Even though halogen bulbs are not immune from creating glare, the relatively high lumen output of gas discharge bulbs (twice as bright), combined with their higher colour temperature (sensitivity to the blue spectrum), tends to exacerbate the glare that an oncoming driver experiences.
The headlamp levelling system is primarily designed to compensate for vehicle load, which is automatic on vehicles where the dipped beam has an output of over 2000 lumen. I do not believe it is designed to react with such speed as to compensate for speed humps, crests, uneven surfaces, etc.
In my experience of driving vehicles with gas discharge headlamps, you do tend to cop the odd high beam every now and again from other drivers. Owing to the bulb's technical characteristics, I don't think it's something that can really be avoided.
I can sympathise though, because I find that my own eyes take longer to recover from the glare generated by gas discharge bulbs (even those from late model European cars) compared to halogen bulbs.
Last edited by Diesel_vert; 06-08-2014 at 10:39 AM.
Thanks for the detailed write up Diesel_vert. It is comforting to know that these lights are indeed brighter than regular halogens which means some may get blinded by it, albeit unintentionally.
Cheers
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