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Old Nov 9th, 2017, 13:32   #26
Traveller11
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Last Online: Dec 24th, 2017 14:39
Join Date: Feb 2017
Location: Newport
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Quote:
Originally Posted by Tatsfield View Post
Short wavelength blue light has less penetrative power than longer wave length red light, hence the last light to reach us through the extra atmosphere as the sun dips down to the horizon is red giving us red sun sets. In damp air a more yellow/white light containing a higher proportion of long wavelength light will throw a longer beam than scattered blue light. Blue light looks brighter but keeping the colour temperature towards the 4000° level will be the best compromise for all round beam length. The auto fashionistas like blue tinged bulbs but this harks back to the days when only exotic cars had HID Xenon lights and the early ones tended to look a lot bluer than they do now.
I think that explains why French cars used to have yellow headlights as it was always damp and foggy over there, then the Government changed to rules and new cars lights changed over to white headlights.

While now of course even though yellow lights are better in damp/misty/foggy conditions you see very few cars if any with at least yellow foglights on the front.

Still I am just glad I could get exact replacements for my headlights without having to go 'Spec Matching' with an alternative and ending up with different headlight colours and intensities!
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