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It's actually garbage for road safety because bluer lamps spaced so far apart creates less even lighting, blows out everyone's night vision, causes distracting

It's actually garbage for road safety because bluer lamps spaced so far apart creates less even lighting, blows out everyone's night vision, causes distracting glare in peripheral vision, and makes it impossible to see into the shadows. The ideal for road safety would be more uniform lighting from a larger number of closer-spaced lamps, placed at lower height, diffused, shielded from the sides, and colored orange (and optionally uniformly dimmer). It would also help road safety to ban the new bluer types of car headlamps, which cause much worse glare than previous yellower ones.

rootusrootus 6y ago
> which cause much worse glare than previous yellower ones The color has almost nothing to do with that. Newer headlights are much brighter, and mostly use projectors now. The increase in glare is mostly due to the projectors, because they emit all their light from small point. You'll notice that newer cars with halogen projectors are almost as bad as one with HIDs. It would be interesting to see how a headlight would look if it were able to emit the same amount of light on the road but from a rectangle spanning the entire front of the car. Minimum glare, still effective.
- jacobolus 6y ago
  > color has almost nothing to do with that The color makes much of the difference. (What really matters is the total intensity in the shorter-wavelength part of the spectrum, so sure, making the lamps much brighter and less diffused is also bad.) Shorter wavelengths cause significantly more glare, because the peripheral part of the human retina is packed with rods and S cones. Intense light including shorter wavelengths also causes the eyes to become bright-adapted, making it harder to see in the dark. The super-bright halogen headlamps emit much more blue light than previous incandescent headlamps, and are included alongside LED headlamps in my complaint here. Bigger, much dimmer, more diffuse lamps would help, but they should also be less blue. (And people should stop mounting headlamps on their SUVs and pickup trucks at other drivers' eye level and aiming them straight ahead.)

rootusrootus 6y ago

> which cause much worse glare than previous yellower ones The color has almost nothing to do with that. Newer headlights are much brighter, and mostly use projectors now. The increase in glare is mostly due to the projectors, because they emit all their light from small point. You'll notice that newer cars with halogen projectors are almost as bad as one with HIDs. It would be interesting to see how a headlight would look if it were able to emit the same amount of light on the road but from a rectangle spanning the entire front of the car. Minimum glare, still effective.

jacobolus 6y ago
> color has almost nothing to do with that The color makes much of the difference. (What really matters is the total intensity in the shorter-wavelength part of the spectrum, so sure, making the lamps much brighter and less diffused is also bad.) Shorter wavelengths cause significantly more glare, because the peripheral part of the human retina is packed with rods and S cones. Intense light including shorter wavelengths also causes the eyes to become bright-adapted, making it harder to see in the dark. The super-bright halogen headlamps emit much more blue light than previous incandescent headlamps, and are included alongside LED headlamps in my complaint here. Bigger, much dimmer, more diffuse lamps would help, but they should also be less blue. (And people should stop mounting headlamps on their SUVs and pickup trucks at other drivers' eye level and aiming them straight ahead.)