UV flashlights, looking for advice on wavelength.

Hi all,

I'm thinking of getting a small, cheap UV flashligh (for curiosity mainly), and have seen a few different types for sale (mainly on ebay).

What wavelength should I be looking for for best usefulness? The light I am considering at the moment is a 12 LED 400nm, running on 3AA cells in a triple cluster (not in line) in the body. The light appears to be about the size of a Nuwai Q3.

Any advice would be appreciated, Thanks.

Nigel.
:touche:

Lower wavelengths are better but it depends on what you want it to do. Here are a couple of links that have some ideas.

What cool uses have you found for your UV LED light?


UV LED lights for tracking blood?

-LT

3AA and even 3AAA won't be the size of a QIII. 400 will look more purple than anything else. Ok if you don't mind the visable light. If you want to make things glow that don't glow at 395-400nm then you should go for 380nm and lower. There are 360nm FoxUV leds on ebay that are a good price if you want to swap out your leds too, they emit almost no visable light and will make just about anything glow that higher wavelengths wont.

But the lower wavelength you go the more dangerous to your eyes, more expensive, and less light output (power) you have. I'd say 380nm would be a good starting point as it's not really expeisnve, has decent light output, and has less visable light than 400nm.

I have something similar that fits in a Maglite's body... I'm very disappointed by the throw on it. I use it for finding pet stains, and it has to be dark with little lighting, and even then I have to bend over to see the flourescence usually, and my eyes are pretty sensitive to light. I'd really like a UV light with better throw and a more concentrated hotspot.

I have had a chance to compare several flavors. I just got some 360nm UV, and they are GREAT for finding UV inks on money, DL's, passports, but not all that hot for things like glow powder gharging, and UV/neon crayons. AND their output compared to 395-400nmUV is less. I am also spoiled by my EDC UV cree running at about 2W.

Jeff

Well, I've ordered a cheapo 400nm 12 LED UV from ebay, and also a pack of 360nm LED from Fox. I will try to mod something when I get the LEDs, I have some cheapo 2 CR123 LED lights around that might be useful, but the LEDs appear to be crimped onto the base board by a metal contact ring, major surgery ahead I think !!

:touche:

RAF_Groundcrew said:

cheapo 400nm 12 LED UV from ebay, and also a pack of 360nm LED from Fox. I will try to mod something

Click to expand...

Hmm. Multiple types/wavelengths of UV LED for a "broad spectum UV"
light? (6*360nm, 6*400?)

BillW

Actually, I was going to leave the bought UV light as is (for now), and mod the white light torch to 360nm, I hadn't thought about mixing the wavelengths, would it achieve anything over a single source UV?

:touche:

OK, from what I have put together, 360nm is GREAT for illuminating hidden inks, 395nm is better for charging GITD stuff and general flouresent stuff. The 360nm appears to have less output than the 395nm.

EXAMPLE:
Here is the corner of my MIchigan DL.



Here it is with some 400nm NUV shining on it, (1) the NUV overloads the camers, (2) I can barely see there there is a circular seal on there.


With 360nm I can CLEARLY see the multi-color hidden image there.




Like I said, different ranges for different uses.

Jeff