UV - comparing 395 nm to 365 nm

[Skaaphaas]

I have had a 24 5mm LED 395 nm-ish UV flashlight for a few months. Cheap as chips and it worked for finding scorpions. It puts out a lot of visible purple light.

Yesterday I received my Nailbender P60 dropin with 365 nm Nichia UV led hosted in a 6P with stainless bezel and McClicky (I'm sure the previous owner is on this forum somewhere!). At first it seemed a bit meek as there is very little visible light.

Then I discovered this: My cubboard door has some stuff that flouresces (don't ask me what!).

Here's a pic taken with the cheap one first, and secondly the rather more expensive Nichia option.

Same spot, different results:

 

[TinderBox (UK)]

Yeah, what best to show up cat urine.

John.

 

[jon_slider]

one of the most obvious differences between 365 and 395 can be demonstrated with a US$100. The 365 will show the red line, the 395 will not.

what best to show up cat urine.

try this link, let us know what you learn

 

[TinderBox (UK)]

one of the most obvious differences between 365 and 395 can be demonstrated with a US$100. The 365 will show the red line, the 395 will not.



try this link, let us know what you learn

See what i found

John.

 

[Skaaphaas]

Yeah, what best to show up cat urine.

John.

Well yes, there are cats in the complex and it would be nice to see if there is any lingering urine in the house that's not been cleaned properly.

I doubt the photos are of that, though, that's the inside of my cupboard door and about 7 feet up. I'm thinking it's some kind of body or hair spray.

 

[Skaaphaas]

one of the most obvious differences between 365 and 395 can be demonstrated with a US$100. The 365 will show the red line, the 395 will not.

I've read as much. Living in South Africa makes that little test somewhat difficult for me, though

 

[ank]

yeah 395nm is worthless.you won't notice that until you get a 365nm light.i wonder what does even lower nm reveal

 

[alf_17]

I think it depends a lot on what you are using it for.
Based on my experiencing with cheap 365nm and 395nm LED's I have found that 395nm makes amber (fossilized tree sap and not the color) fluoresce more than 365nm.
I have just received my AceBeam X80 today, which has a Nichia 365nm in it, so I guess I need to test it against the cheep 365nm and 395nm LED's.
Based on my memory I can say for sure that the Nichia 395nm has far less visible light output than the cheap 365nm, which seems to output a lot of white'ish visible light.

 

[Skeptic50]

I found a really great article about the difference between 395nm UV and 365nm UV at https://www.waveformlighting.com/tech/what-is-the-difference-between-365-nm-and-395-nm-uv-led-lights. Basically, the visible light spectrum is from 400nm to 800nm. The 395nm lights are only 5nm below the lower end of the visible light spectrum and they emit a pronounced violet-colored light because the light frequency emitted is actutally a bell curve and the 395nm curve extends into the visible light spectrum. The 365nm lights are "deeper" into the UV spectrum, 35nm below the the lower end of the visible light spectrum and they emit a dull, bluish-white light. The bell curve on the 365nm lights do not extend into the visible light spectrum. So 365nm are "purer" UV lights. However, "both types emit in the UV-A wavelength range and are generally capable of producing blacklight effects or curing effects" on UV cured adhesives. I hope this give many of you some solid information on which frequency of "blacklight" flashlight you want to buy. After reading the referenced article I intend to go for 365nm flashlights until I am persuaded otherwise. Thanks for reading this.

 

[wle]

lots of stuff (that isn;t cat pee) glows blue

including fabric whiteners, soaps, detergents

wle

 

[jon_slider]

to show tritiums in a photo during the day, I like to use
365nm UV:

No UV

395nm UV is too purple: