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points by mahboi 3 days ago | 0 comments

Welp, they do for mine. I've had to stop turning on outdoor LEDs because angry bees kept showing up, and there'd be 3-10 dead ones on my doorstep every morning. These are white bulbs. Might be "zombees."

Also, not sure about white bulbs, but those color-configurable spotlights definitely emit UV at least when set to anything near blue/purple. They cause certain things to glow. Probably white is doing it too but it's harder to see.

[–] legitronics 3 days ago

The color configurable bulbs or the high CRI bulbs typically use a 400nm led source and some do use a 380nm but those are much rarer and expensive. Also almost any amount of plastic or glass will significantly absorb that wavelength of UV.

I have a 405nm laser pointer and it makes certain things (any% titanium dioxide) absurdly bright from fluorescence. So you probably aren’t getting UV from those bulbs, but certainly some IR.

[–] lightedman 3 days ago

"The color configurable bulbs or the high CRI bulbs typically use a 400nm led source and some do use a 380nm but those are much rarer and expensive."

Cree, Nichia, et.al. use ~460nm LED with a cerium-doped aluminum-yttrium garnet cover to convert to white light and have done so for at least half a decade. Just a bare look at the spectral output chart from any company will tell you the wavelength of the base emitter, with a MASSIVE output peak centered around 460nm.

Nobody has used UV as a white LED base for well over a decade or more.

[–] sbierwagen 3 days ago

You don't need UV to stimulate florescence. 395nm blue light will cause yellow highlighters to light up quite brightly: https://par.nsf.gov/servlets/purl/10326338

[–] mrheosuper 3 days ago

UV-A starts from 400nm, so there is no "395nm blue light"

[–] Dylan16807 3 days ago

400nm by virtue of aggressive rounding. 395nm is well inside the visible range.

[–] joquarky 2 days ago

I'd love to see you provide proof that people can't perceive blue qualia from a 395nm EM exposure.

[–] hk1337 3 days ago

Yeah, we have solar powered LED lights in the walking path where I live and the lights are covered with them. They look nasty.

[–] lightedman 3 days ago

"those color-configurable spotlights definitely emit UV at least when set to anything near blue/purple"

Nope. Blue light just happens to do well at exciting fluorescence in some materials, especially bleached and whitened ones like paper and laundry. 420nm blue light will excite red fluorescence in a ruby. 532nm green will induce BIP in calcite. Certainly no UV present in an upconverted IR laser.

It's not UV.