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.
Unlike most of the "Top 10 flashlights" lists you find on Google, we actually owned and reviewed hundreds of flashlights on our team. Many of those lists are written by people who know nothing about flashlights! In fact, many of these people do not even own any flashlight. How we can tell? They show utterly ridiculous flashlights that should never ever be recommended. I'll do my absolute best to help you with real knowledge. I have been active on flashlight forums since 2009.. (check out our ‘About Page’) and have owned well over 100 flashlights at that time. Please ignore my non-native English, because I'm actually Dutch.. ; --)
The 11 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, the LED of the Weltool M2BF is not accessible.
Test 1: Counterfeit Money Detection
In our first test, we are going to see which of these flashlights can detect special ink in the bills that only appear under the proper wavelength of UV light. Because it's illegal to own any counterfeit bills or money, we will only show real bills.
I set the camera to ISO1600, F4, but with automatic shutter speed. The Jetbeam and Ultrafire flashlights were very weak so it's either extremely bright or extremely dark. So automatic shutter speed did the trick.
Some flashlights have clear visible light. The Xanes 51UV uses 395nm UV light, but as one of our readers have pointed out, they may actually be way above 400nm and just purple light. The brightness of the pictures changes with the brightness of the flashlight and how you hold it. Sometimes, the pictures is washed out like with the Mantaray S1 and a little bit with the Convoy C8. The Convoy is built to 'throw' a beam. So this is not recommended for close up work.
On top of that, every half-decent UV LED is able to show the watermarks on paper bills. It may be a decision between flashlight with a hotspot or a floody beam.
Test 2: Paint anomalies
Want to know how well painted your white walls actually are? UV flashlight can actually show (under some circumstances how well painted a wall really is). These are white drywall panels and white paint. In person, you can't really see there are any problems with the painting. But with a UV light, it becomes pretty obvious.
Again, the camera was set to ISO1600, F2.8, and Automatic shutter speed.
The Jetbeam Jet UV, Ultrafire SK68, Sofirn SF32UV and Xanes 51UV are clearly the losers in this test.
The Weltool M2-BF, Jaxman U1, Jaxman U1C and Convoy S2 have a wider beam with less of a hotspot!
Test 3: Unkown substance
Although I wanted to test dried blood, even without using a UV flashlight the blood was visible, so not very exciting. I also wanted to test Radiator Coolant, but after 7 days the coolant was invisible on the carpet. Then I tried the same with cooking oil. Again, after 7 days it was impossible to notice on the multi-color carpet.
The following test is one that is from an unknown substance. The camera was set to ISO1600, F5, 1/3 sec. Weaker lights are darker.
After these tests I noticed that the Jaxman U1C has actually 2 modes. I probably used the lower mode in this picture. For this kind of environment, the winners are clear. The SK68 was simply too weak with this camera setting.
Test 4: Visible light
In the following test, I wanted to show the difference in visible light, projected on a black background. Unfortunately, that test failed. After using a black background, I decided to do it on a white(ish) wall. The camera was set manually to ISO1600, F5, 1/25 sec with a 100mm lens.
The Jaxman U1C was set to its highest mode but has a very wide beam. From this list, the Weltool M2-BF is showing the least visible light, while the Xanes, Jetbeam Jet, Sofirn, and Ultrafire showed the most visible light. These 4 are performing the worst of the bunch in all tests.
Test 5: ZWB2 UV Filters
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 next pictures, I placed both filters on top of a normal white LED flashlight to check for any differences. And although I can't really measure the difference, you can see a slight color shift between the 2. They perform both really good and the most important things you can check with UV light only, work with both filters.
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.
Winners and losers
One of the major differences between the winners and losers is the use of a ZWB2 filter. Besides that, you have to think about the battery it uses as well as the application.
Clear losers of this test are Jetbeam Jet UV, Ultrafire SK68UV, Sofirn SF32UV and Xanes 51.
Winner for long-distance (2meter +): The Convoy C8 is clearly the best option with the largest reflector.
Winner for close up: Jaxman U1C with the widest beam and Weltool M2-BF with 2 brightness levels.
Winner for medium range (1-2 meters): All Convoys, Jaxmans, and Weltool did a terrific job.
Winner with least visible light: Weltool M2-BF
Jetbeam Jet UV
Manta Ray S1
Least visible light + 2modes
Convoy C8 UV
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
How to test UV flashlights?
Generally speaking, measuring the output on 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. The lower the number the less visible. So the output is hard to measure.
Here is a nice piece of content written by Djozz, that shows a technique on how to measure the output of UV flashlights. He compares some the 'better' UV LEDs used in flashlights. He tested 4 LEDs, namely a Nichia 276 A U365, LiteOn 3535 365nm, Luminus SST-10 365nm and a Nichia 233B 365nm LED.
Here is another thread with 4 more tests: http://budgetlightforum.com/node/59304
Learn more about UV light?
Weltool produced a nice writeup about UV light for flashlights. You can read their article here.
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's and LG's are high quality and affordable. Nichia NCSU276A U365, 5MM LEDs are not really recommended unless using for fun. 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 flashlight.
Are UV flashlights dangerous?
Just like with any other flashlight, don't point it to your, or someone else's eyes. KISS