🧂 My Review of Sodium-Vapor Lamps
If you're not familiar with sodium-vapor lamps, Wikipedia describes them thusly:
A sodium-vapor lamp is a gas-discharge lamp that uses sodium in an excited state to produce light at a characteristic wavelength near 589Â nm.
Wikipedia is being very polite when describing the light produced by these lamps as, "a characteristic wavelength near 589Â nm." For contrast, I would describe sodium-vapor lamp light as, "a horrific shade of yellow that stands as a moral and aesthetic affront to most sighted creatures."
Back to Wikipedia for a few more important details:
Two varieties of such lamps exist: low pressure and high pressure. Low-pressure sodium lamps are highly efficient electrical light sources, but their yellow light restricts applications to outdoor lighting, such as street lamps, where they are widely used. High-pressure sodium lamps emit a broader spectrum of light than the low-pressure lamps, but they still have poorer color rendering than other types of lamps. Low-pressure sodium lamps only give monochromatic yellow light and so inhibit color vision at night.
To sum that up: the light these lamps produce is hot garbage. Just terrible. The urine of the visible spectrum. Every time a sodium-vapor lamp is decommissioned and replaced with any other kind of light an angel gets its wings.
However, due to their unique properties, these lights do have some interesting use cases. For example, in the film Mary Poppins, sodium-vapor lamps were used with a unique prism to create a compositing effect which, in many ways, is superior to the green screen techniques widely used today. (Don't skip that link, it's fascinating!)
Still, for any traditional applicaiton, these are the worst.
Thankfully, the end is in sight:
In 2017 Philips Lighting, the last manufacturer of LPS lamps, announced they were discontinuing production of the lamps due to falling demand.
A wise decision!
Modern LPS lamps have a service life of about 18,000 hours and do not decline in lumen output with age, though they do increase in energy consumption by about 10% towards end of life.
Does math...
So they last just over two years if they're on 24 hours a day, seven days a week, or they'll last roughly six years if they're only on for eight hours every night.
Six years...
Initially, production was due to be phased out in the course of 2020, but this date was brought forward and the last lamps were produced at the Hamilton factory on December 31, 2019.
Assuming these horrible things were all put into service relatively quickly after production, that means we have only a couple of years left before these luminal abominations are relegated to being a historical curiosity instead of a daily annoyance. With any luck at all there isn't a big warehouse of unused ones somewhere, but only time will tell.
If you'd like to learn more about sodium-vapor lamps Alec Watson of Technology Connections made a video about them which, like every other video he makes, is absolutely phenominal.
My rating: 💡 out of 💡💡💡💡💡