I have tried to swear off further posts on light pollution, feeling my prior writings suffice for the time being. However, this week I walked into an empirical example that I simply could not ignore.
While getting off the train one night, I was on a section of platform that had recently been renovated. It had received a new walking surface, and the lamp light bulbs had been replaced with newer LEDs. Within a few paces of one of these lamps with the new bulb was a lamp with an older bulb, closer to the parking lot. I assumed this was a sodium bulb, or at least it exhibited the characteristics of the old sodiums.
I was able to take a picture of both lamps from the same location, posted here above. On the left is the old sodium (-like) bulb, and on the right is the new LED bulb. From my vantage point that evening I quickly observed differences in experiences from being under the light of both.
First, both lights were overall too bright, and they were unshielded. You can see how the lamp design does very little to restrict the light towards its intended targets. While the light mostly heads towards the ground, it disperses in all directions, including up. There are probably at least a hundred of these lights throughout the train station area.
Aside from these issues, all else being equal, here is what I observed, first on the sodium/older bulb:
- Had a softer glow. I could look in the direction of the bulb and not feel irritated.
- Does a far better job of bathing and immersing its surroundings in light. The entire area around the lamp definitely looked “lit up”.
- For night, it was relatively easy to make out all the objects around the lamp.
- The color of the lamp distorts the natural color of the surroundings.
For the new LED bulb:
- Projected a very harsh brightness. Cannot comfortably look in the direction of the bulb for very long.
- The ground around the lamp looked very dark compared to the area around the sodium bulb. I could definitely see everything but I also felt like my eyes were straining to see the area.
- The color was more neutral/white than the sodium, but this was offset by the weaker luminous feel.
- In my peripheral vision, the bulb was distracting. I’ve noticed this while driving, too.
Any energy savings of these newer LED bulbs are offset and nullified by their degraded functionality. They seem to be very good at pinpoint brightness but are unable to luminate their surroundings effectively. On top of that, they are grating on the eyes.
Ultimately, any bulbs (except blues) should be fine for nighttime function so long as they are properly shielded. I have seen and walked under “dark sky” lights and they are fine for their intended purpose. These accompanied with motion sensors and smart electronics would go a very long way towards helping reduce light pollution.