UV radiation exposure can damage the cornea, the outer protective coating of the eye. Photokeratitis is a painful inflammation of the eye caused by UV radiation-induced lesions on the cornea. Symptoms include a “sand-like” feeling in the eye last can last several days. Chronic exposures to short-term UV radiation can lead to the formation of cataracts.
Never point a UV flashlight directly into somebody's eyes, nor via reflective surfaces like windows, tiles, or mirrors.
We reviewed hundreds of flashlights, no joke
Unlike most of the "Top 10 UV flashlight" lists you find on Google, we actually owned and reviewed hundreds of flashlights on our team. Many of those lists in Google are written by people who know nothing about flashlights! In fact, many of these people do not even own flashlights. How we can tell? They show utterly ridiculous flashlights and never share any useful measurements data. I'll do my absolute best to help you with real knowledge. Please ignore my non-native English, because I'm actually Dutch.. ; --)
Oh, want to read other flashlight reviews? Read one of our 516 reviews!
The 11 UV light contenders
|LED||365 nm UV||Seoul 365nm 3W||365nm||Nichia 365UV||LG UV 365nm||365UV||Nichia 365nm UV||LG 365||Seoul 365nm||395nm||LG UV365nm|
- Unfortunately, I couldn't take a picture of the UV LED of the Weltool M2BF, because the bezel is glued.
- The LG UV LED in Sofirn's flashlight, looks more like a Nichia 365UV (like the one in the Convoy S2+). You can compare the LED with the one of the Convoy S2 (which is an LG UV LED).
1: Counterfeit money detection with UV
Now, I will check which flashlight shows the ink used in these bills. These 'hidden' characteristics only appear under the proper wavelength of UV light. Because it's illegal to own any counterfeit bills or money, I can only show authentic money.
I set the camera to ISO1600, F4, but with automatic shutter speed.
Jetbeam and Ultrafire flashlight are much weaker than the competitors so I had to use the auto shutter speed function on my camera.
UV light should be invisible to our eyes, because of the wavelength. UV flashlights are often referred to as 365nm or 395nm. The 365 nm is deeper into the UV spectrum and has less visible light.
Basically, 365nm is preferred over 395 for most applications where UV is needed.
Some points to make:
- The Xanes 51UV uses a 395nm LED, but may actually be above 400nm. The beam looks purple instead of a deep blue/purple.
- Mantaray S1 has a lot of visible light and makes it hard to see the bills. The same goes for the Convoy C8. The Convoy C8 has a deep reflector and the beam is more 'throwy' (meaning: it's meant for long-distance use) and therefore, not recommended for close-up work like checking bills.
- Lastly: every half-decent UV flashlight is able to show watermarks. The main difference is in the minute details, and the width of the beam.
2: Test Paint anomalies with UV
Ever wondered how well painted your white walls are?
Use a UV flashlight.
For this test, I checked painted drywall boards with all the Ultra Violet lights. In person and with normal lighting, these boards look perfectly white to the eye, at least.
But when you use a UV flashlight, you will notice the parts that aren't painted very well.
Again, I used the following camera settings: ISO1600, F2.8, and automatic shutter speed.
The Jetbeam Jet UV, Ultrafire SK68, Sofirn SF32UV, and Xanes 51UV are unquestionably the losers.
The Weltool M2-BF, Jaxman U1, Jaxman U1C, and Convoy S2 have a nice beam without too much visible light in the hotspot!
3: Find unknown substances with UV
For this test, I wanted to see if I could observe dried blood on clothes. But even without using UV light, these spots were visible, so kind of useless to use UV. Then, the owner of Weltool recommended testing Radiator Coolant, but after 7 days of waiting, the coolant wasn't visible with any light I tested.
He also recommended testing with cooking oil. And again, after 7 days of waiting, it was impossible to notice cooking oil on the carpet I used for testing.
So... I walked around in the dark, searching for a spot with an unknown substance... and I found it....
I used the following settings on my camera: ISO1600, F5, 1/3 sec. Again, the weaker lights don't look very good in the pictures.
Only after I performed this test, I noticed that the Jaxman U1C has actually 2 modes. I presumably used the lower mode in this picture. For this kind of environment, the winners are clear.
The SK68 was simply too weak with these camera settings.
Ultraviolet light can be used to find unknown substances, but as you can see, the differences between the different UV lights are obvious.
4: Test visible light in UV
In the following test, I wanted to show the difference in visible light projected on a black background. Unfortunately, that test failed. So, after using a black background, I decided to use a white(ish) wall.
The camera settings are: ISO1600, F5, 1/25 sec with a 100mm lens.
From this list, the Weltool M2-BF is showing the least visible light, while the Xanes, Jetbeam Jet UV, Sofirn, and Ultrafire showed the most visible light.
These 4 flashlights perform the worst in all tests.
5: Test filters for UV flashlights: ZWB2
Block visible light with a ZWB2 filter
A zwb2 filter looks like a black piece of glass, but in reality, it is used to block out any visible light a UV LED may produce. Cheaper UV LEDs tend to produce quite a bit of unwanted, unnecessary visible light. A couple of years ago, these zwb2 filters were very expensive, but nowadays you can get them for less than a dollar. Actually, I bought mine for $0.47 and 0.46 respectively.
I chose 2 sizes: 19.5 x 2mm thickness and 20.5 x 2mm thickness. And yes, they work just fine! They will fit the Convoy S series well.
Here are the Convoy filter and Aliexpress filter next to each other.
Cheap zwb2 filter test
In the following 2 pictures, I replaced the original Convoy S2 zwb2 filter with the cheap Aliexpress filter. On the left is the original one on the right is the cheap replacement.
In the following pictures, I placed both of these filters on top of a standard white LED flashlight. I wanted to see if there were any visible differences. And although I can't measure the difference, you can see there is a slight color shift between the 2.
Bottom line: both of them perform well.
The performance of the cheap zwb2 is actually pretty good. Again, I don't have the actual measuring tools to measure UV, so I try to show the difference with pictures so you can decide for yourself. For less than $0.50 I'm very happy with these cheap alternatives.
If you want to buy a Sofirn SF32UV, make sure you buy this filter to improve its quality a hundredfold.
UV Test conclusion:
Winners and losers
The worst and best blacklight flashlights we tested
The use of a ZWB2 UV filter makes the biggest difference between the winners and losers. So that would be the first recommendation: Get a UV flashlight with UV filter.
Secondly, decide what battery configuration you want. If you really want to use AAA batteries, you might be out of luck.
The losers of my tests are:
- Jetbeam Jet UV
- Ultrafire SK68UV
- Sofirn SF32UV
- Xanes 51
If you need UV light, don't get one of these flashlights.
Long range: Best long-distance UV flashlight:
If you want need a UV flashlight that can throw far, there is 1 clear winner in this category:
- Convoy C8
It has the largest reflector and therefore throws very well.
Close range: Best UV flashlight for close up work:
The best UV flashlights for close up work are:
- Jaxman U1C (with the widest beam)
- Weltool M2-BF (with 2 brightness levels)
Medium range: Great UV flashlight for medium distance:
- All Convoys,
- All Jaxmans
Best UV flashlight with the least visible light:
- Weltool M2-BF
The Weltool was the best performer in this category. It's also the most 'professional' UV flashlight I tested.
Buy UV flashlights here:
Jetbeam Jet UV
Manta Ray S1
Least visible light + 2modes
Convoy C8 UV
BONUS: UV flashlight parts
P60 UV drop-in
P60 type flashlights were extremely popular 5-10 years ago but are still very useful. One of the most significant benefits is the straightforward replacement of the P60 Drop-in. Unscrew the head, take out the existing P60 drop in and replace it, screw it back together. Done.
Fortunately, there are still some (smaller) P60 makers who sell P60 UV drop-ins.
Unfortunately though, your options are limited.
The Sportac P60 365nm UV used to be very popular but isn't available at most places any longer.
Sportac P60 UV
LED brand: unknown
UV LEDs mounted on LED boards
If you are sure you know how to mod flashlights, this might be one of the cheapest options. Simply, order a MCPCB board and add it to your favorite flashlights! Simple
Luminus SST-10 UV 365nm
3W LG UV 365nm
5W LG UV 365nm
BONUS: How to test your UV flashlights?
Generally speaking, measuring the output of UV LEDs can be very difficult. Lux meters don't do a proper job because they can't measure UV light correctly. UV lights are in the wavelength between 310-400nm, that lux meters usually can't measure. The lower the number the less visible.
Here is a nice piece of content written by Djozz, that shows a technique how to measure the output of UV flashlights. He compares some of the 'better' UV LEDs used in flashlights. Namely a Nichia 276 A U365, LiteOn 3535 365nm, Luminus SST-10 365nm, and a Nichia 233B 365nm LED.
If you want more UV tests, check out this thread: http://budgetlightforum.com/node/59304
Learn more about UV light?
Weltool produced a nice write-up about UV light for flashlights. Unfortunately, their article was taken down.
Also, Weltool is one of the few companies that have a lineup of high-quality UV flashlights for different purposes. Danny, the owner of Weltool told me personally that he actually studied UV light for a long time. So if you are looking for a seller that really understands UV light and the benefits etc. definitely take a look at Weltool's products!
What are currently the best UV LEDs for flashlights?
There are a few UV LEDs that are high quality and work very well for their purpose. The Nichia LEDs and LG LEDs are high quality and still affordable. Note that the Nichia NCSU276A U365, 5MM LEDs are not recommended. Since UV LED emitters are very sensitive to heat, you better buy a thoroughly tested flashlight from a trustworthy seller, and not from eBay. Unless, of course, you know the seller and the flashlight.
Are UV flashlights dangerous?
Just like with any other flashlight, don't point it to your, or someone else's eyes. KISS
What are Black Light flashlights then?
You'll find that black light flashlights and UV flashlights are used interchangeably.