# A new UV bulb at Wally World



## PhotonWrangler (Sep 9, 2018)

I stumbled across this UV LED bulb at Wally World today so I picked one up. It has an edison E26 base and a clear dome with a single LED in it.

Powering it up, it does produce fluorescence, although with some visible purple light, This suggests that it is one of the longer wavelength LEDs, probably closer to 395nm than the classic 365nm blacklight wavelength.

Placing a woods glass filter in front of it confirmed this; the fluorescence completely disappeared with the filter in place. This shows that there is no 365nm energy coming from this LED. I was somewhat disappointed, although this wasn't completely unexpected for a $7.00 lamp.

As a point of comparison, the Feit filament LED blacklight bulb produces the same result with the woods glass filter. In my opinion, either bulb would be good enough for basic blacklight effects but not suitable for differentiating currency security strips or stamp collecting.


----------



## ampdude (Sep 9, 2018)

I'm not sure they can sell a 365nm bulb, wouldn't that be damaging to the eyes? I wear safety glasses when I use my 365nm flashlight.


----------



## FRITZHID (Sep 9, 2018)

Agreed ampdude, too much liability. 
Sad considering the much better blacklight effect they'd have. I wonder if a few low wattage 365nm along with some more powerful 395nm LEDs would work...


----------



## PhotonWrangler (Sep 10, 2018)

365nm _fluorescent_ blacklight bulbs are commonplace in these stores. I saw some just a few feet away from the NUV LED bulb.

_Shortwave_ UVC bulbs are really hard to find in stores, but then they're not used for blacklight effects. They're used for killing germs, and can sometimes be found as replacement lamps for air & water filters. These are very nasty to living things, and they're usually hidden away deep inside the product where they won't hurt anyone's eyes.


----------



## PhotonWrangler (Sep 11, 2018)

Here's a good example of the difference between ~395-400nm NUV light and a "real" 365nm UV light - 

Fluorescent Sodalite found on the shore of Lake Superior recently. The first flashlight is clearly a 400nm NUV lamp and barely does anything with the rock. Then the second flashlight that we see (briefly) hits the rock with 365nm black light and it springs to life. Sodalite glows a bright yellow-orange under 365nmm UVA light.


----------



## MeMeMe (Sep 13, 2018)

PhotonWrangler said:


> Here's a good example of the difference between ~395-400nm NUV light and a "real" 365nm UV light -
> 
> Fluorescent Sodalite found on the shore of Lake Superior recently. The first flashlight is clearly a 400nm NUV lamp and barely does anything with the rock. Then the second flashlight that we see (briefly) hits the rock with 365nm black light and it springs to life. Sodalite glows a bright yellow-orange under 365nmm UVA light.



Sodalite does fluoresce under 395-400nm LED, but there is so much visible purple that it washes out the typically orange fluoresce.


----------



## PhotonWrangler (Sep 13, 2018)

MeMeMe said:


> Sodalite does fluoresce under 395-400nm LED, but there is so much visible purple that it washes out the typically orange fluoresce.



This is a more accurate description. Thank you.


----------

