Headlights effect on range?

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Holy crap! I've wondered about the uneven shadow. Thanks! Why does it need that uneven shape??

The step is intended to not blind oncoming traffic as much while still illuminating far enough down the road. I'm pretty sure it's a US only requirement (DOT), not sure about Canada. Europe has a different beam pattern (ECE):

headlight-cutoff.webp

It's common for people in the US to buy the European version of headlights (sometimes called "E code") as an upgrade since they illuminate a lot more of the side of the road.
 
It makes sense that there’s something blocking the low beams to create the cutoff pattern. But you can still see the sharp stepped cutoff pattern when you turn on the high beams. If there were a mechanically actuated shutter that moved out of the way when you turned them on, you wouldn’t see the pattern any more.
 
It makes sense that there’s something blocking the low beams to create the cutoff pattern. But you can still see the sharp stepped cutoff pattern when you turn on the high beams. If there were a mechanically actuated shutter that moved out of the way when you turned them on, you wouldn’t see the pattern any more.

I see that too and it does seem to be different than the moving shutter. It's really hard to get a good picture of the inside (the lens has a golf ball texture to it) but I can sort of see what's going on based on the light hitting all the dirt on the outside of my headlight lol.

It appears to me that the headlight is split into an upper and lower half with a visible dark line between them. I blocked off parts of the headlight with tape and found this:
  • The lower part is responsible for the majority of the low beam and does not change when switching between low and high. This lower part is the half with the cutoff shield (and the shield is likely fixed).
  • The upper half contributes a little bit to the low beam but not much. The upper half is responsible for all of the extra light with the high beam and seems to have extra LEDs that turn on.
  • The headlight itself moves up and down when switching between low and high beams. It is subtle but I think the purpose is to point slightly upwards so the cutoff line that's still visible with the high beams on is not as noticeable. This subtle motion is why I originally thought there was a moving shutter but the high beams come on before the motion so it's clearly just the headlight adjusting.
Here's a pretty poor quality video:
 
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