Review: UV light shootout, seven lights tested

UV, its should be a glowing report.

I tried out one of these emitters that I paid $28.99USD shipped for 5 emitters. I can't tell if it's the real thing as I have no measuring equipment and have very little experience with UV lights. I drove the emitter DD with 3AAA's. Here is what I observed:

  • The emitter did not put out much visible light, but what it does put out seems almost a neutral white compared to my other two UV lights that have 5mm emitters. One of the 2 is supposed to be 395nm and the other is unknown.
  • It fluoresces white objects ok. Colored objects that fluoresce well with the 395nm light, don't fluoresce much with this emitter. It fluoresces urine, but not a brilliantly as with my 395nm light.
  • GITD items fluoresce well.
  • I got best results in mule mode. Both a reflector with a plastic lens and a TIR optic reduced output except for in the hot spot.

Edit: After using the emitter more now I'm thinking this may not be 365nm emitter. Almost everything seems to fluoresce better with my 12 emitter 395nm light. Also, the visible portion of the beam almost seems a neutral white. Kind of a creamy tan tint.

Where’s the Canadian money? We got new polymer bills too :slight_smile:

Let me know which ones you want and I’ll get some over to ya!

-Jamie M.

Those bills are crazy Toysareforboys. I appreciate the offer, but I don't think these emitters are worth it. I'm going to complain to the vendor today.

How do GITD items compare with your 395nm?

Hi Helios-. The 395 fluoresces GITD stuff much more brilliantly. I'm thinking these emitters are actually higher frequency than the 395's.

That’s what it sound like.

:frowning:

When I looked at specs from the makers of higher power LEDs in that 365 nm range (The 365 is a LOT more expensive than the 395, esp as the watts go up, etc.)…

It seems to me that the situation is analogous to the tint situation for the Vis LED’s, in that the cooler tints are cheaper per lumen, and the longer wavelength UV are cheaper per watt per unit area emitted.

So a really strong 365 nm UV LED looks to cost closer to $150 for a real one…for just the LED, unless you are buying huge volumes, etc.

That means the ones for under $100 or the LED itself are probably either lower output and/or longer wavelength.

I had a Xenopus I got a few years ago that actually had great output, but, I use these things for work, and they get banged around a lot, and it needs to be replaced. I ordered another Xenopus UV to replace it, and I’ll let you know if it looks to be a good option in that 365 nm range.

I might be overpaying compared to a DIYS on this, but I don’t have the time to mess with it at the moment, and needs are current, etc.

If I was better versed in how to wire UV LEDs, etc, I might put in the research, but now, I can’t afford the time.

:smiley:

Yeah, I should have known better, but I was hopefull. I think you're right. If you want real 365nm, you have to pay the big dollars. Maybe, the vendor just made a mistake and send the wrong emitters. I have inquired, but have not received a reply yet.

Best of luck on your new acquisition Teej. Look forward to your report on it. Even if it isn't budget.

I use them for work, so, its budget, as in, my expense budget for forensic gear.

:smiley:

Actually since you said its visible output is white your led sounds like 365nm.

Do you see purple with your 395nm? How far each person can see into the edges of visible range can differ.

365nm leds are not as efficient as leds above 380nm. A 3W 365nm led puts out a lot less photons then a 3W higher wavelength UV LED. Compare LED Engin's High Power UV leds

700mA @ 3.9 V gives 550mW of 400nm light or 385nm.

700mA @ 3.9 V gives 200mW of 365nm light.

365nm is only 36% as efficient as 385nm here. This is for a quality name in high power UV leds, don't know how efficient chinese 365nm leds might be. Plus like with chinese lumens these may not even be "3W" to start with. Who knows what output to expect in the end.

Sort of need a known 365 and maybe 385 led to check how you see the visible output & compare to these chinese 3W leds.

Interesting info Helios-. Now I'm wishing I had not yet contacted the vendor. I will try to google this later, but are you aware of anything that would fluoresce better under 365nm light vs 395nm light?

With the 395nm light, I see a very slight purple tint. My even cheaper 5mm UV light emitts an more purple tint then the 395nm light.

I use my UV drop-ins to “power-up” GITD items and I’ve seen something that makes me think the 365nm drop-in that Kaidomain sold me (actually I was so impressed I bought another) is the real deal.
I bought some GITD red paint from Kilabitzzz , an ebay seller that has grown and now has a “brick and mortar” store as well. This paint is cream coloured when discharged, when the Solarforce or any of the others I have except Kaidomain’s 365nm shine on it remains cream with a bit of violet thrown in then when the light is off the GITD paint fluoresces. With the Kaidomain’s 365nm drop-in the GITD paint fluoresces immediately the beam touches it and the effect is brighter and lasts a bit longer. This goes for all the GITD stuff that I have including the powders and paints, they show colour immediately. It makes me think that it is nearer a true 365nm with less white light produced.
The Kaidomain drop-in also shows up detail on banknotes that the others don’t.

Thanks for the info 8steve88. Thanks for including all the info to allow one to replicate the test.

I've been Googling and have only found one definitive test that an average joe can replicate. It involves Canadian currency like Toysareforboys mentioned. Here is one example.

I don't have any Canadian currency here. When I was testing the emitter out on a US $5 bill, the 365nm emitter would not show the "05" that are scattered around on the left of the back side of the bill. The 395nm light revealed them clearly. Same with the embedded strip and other details. I don't know what that means though.

That is very similar (different wording and patterns obviously) to what I get with U.K. £10 and £20 notes, very little hidden detail with drop-ins other than the Kaidomain which gives strong details - 10, 20 and patterns.

We need someone to make a UV triple drop in with different LEDs for each of 3 LEDs. Then we could have one drop in to fit all of the different nm outputs. :slight_smile: We would have the best of all worlds. :wink:

OK, it arrived. I have a Xenopus Electronix High Flux 365nm UV LED Light.

It uses a Nichia 365 nm UV, it looks like a NCSUO33B LED in the specs…and uses an optic (No reflector), looks sort of Carlco-ish, but square? - About a 10º beam angle…it actually THROWS. :smiley: The LED itself says 365 nm and N1UV-R3, and XeLED…which is different than the specs list, but I don’t know if its just a labeling thing yet or not.

It can take two CR or RCR123’s or an 18650…I popped in RCR’s to see if it came on at least…which it did.

Holy CRAP its SO much better than my prior UV LED’s. Its rated at 450 mW at 365 nm according to the Nichia LED chart. The flashlight itself is rather generic looking, nothing special there…except the optics and so forth at the emitter end.

I haven’t had time to do much more than open the box, load in some cells and shine it around so far…but, so far at least, its a beast. Almost nothing visible, but it fluoresces stuff VERY strongly, and even with just that quick shine around, I think I found a water leak I didn’t know about, due to changes in paint that were completely invisible by regular light, but jumped out under the UV…typically the minerals that are left behind when the water evaporates.

:smiley:

So whatever its got in there, etc, works, and I like it.

I have been out on emergency work since ~ Monday, and need to get some shut eye though…so I’ll try to get some pics/tests later in the week.

That’s what it looks like at least.

:smiley:

And, yeah, that gasket popped out when I was putting the lens back on. (Fixed now)

The body tube screws down into the head with the head’s female threads actually going past the board, so the body tube threads down into the head deeper than the board.

Very nice, Teej! :bigsmile: Thanks for the photos!

Nice. Thanks for all the photos. I just googled the light. Is it really a budget light? Looked kind of pricey.

Well, budget is relative, as I shopped around, and for the specs, this was the cheapest. I use these things for work, so, I have an expense budget to stay within, and, I did, so, it is a budget light in that regard.

:smiley:

I also previously ordered some drop ins and other stuff, but it never put out what I needed, so, for the money, so far at least, this thing hit the sweet spot. For example, there were versions from other suppliers that were 3x as much.