Contents
- Pricing & Availability
- What comes in the box?
- Design & Construction
- Size & Measurements
- User Interface
- Emitters & Beam
- UV
- Mode Chart
- Runtime
- Driver & Regulation
- Switch
- Carry & Ergonomics
- Batteries & Charging
- Competition
- Conclusion
Pricing & Availability
Olight sent me this light in exchange for an honest review. Here’s the official product page where it and other products will be on sale at for a few more hours following the posting of this review. That’s a tracked link so they know I sent you, but I’ve chosen not to earn any commission. You can also use discount code “tgreviews” for 10% off most products that aren’t otherwise on sale.
What comes in the box?
Arkfeld UV comes in the same style box as the original Arkfeld. It’s simple folded cardstock with some nice printing to show off the light and its specifications. It’s opened with a disposable pull tab on top so it cannot be closed back up once it’s opened. The following items are included in the box:
- The light itself
- Magnetic charging cable
- User manual
- Safety warning booklet
Design & Construction
Arkfeld UV’s design is an iteration on the original Arkfeld design and it still looks like an old apple TV remote. Olight has added some milling on the sides for added grip and has made the flare-out at the tail much smaller. It’s a substantial improvement but it’s so close to being perfectly flush that I wish it were actually perfectly flush and had no flare-out at all. There’s also a new pocket clip which I’ll discuss later.
Build quality is excellent as I’ve come to expect from Olight. It feels solid and dense in the hand with no sharp edges or imperfections. Everything is tight and expertly assembled.
Size & Measurements
Olight Baton 3 | Acebeam Pokelit AA | Olight Arkfeld UV | Lumintop FW3A | Convoy M1
| Measurement | Measured (mm) |
|---|---|
| Thickness (at head) | 15.0 |
| Max thickness (including clip) | 21.5 |
| Width | 25.0 |
| Length | 110.3 |
| Switch Diameter | 9 |
| Switch Proudness | 0 |
| Ride Height (sticking out of pocket) | 2.8 |
| Pocket Clip Space (for pants material) | 3.2 |
| Pocket Clip Space (at mouth) | 2.8 |
| Pocket Clip Width | 5.1-10.0 |
| Pocket Clip Thickness | 0.8 |
Weight: 86g
User Interface
Olight has their UI pretty nailed down. It’s advanced enough to have all the functions most people will want but it’s still simple enough that you can hand it to someone and they can figure it out without much explanation. I do have a few minor critiques though.
The actions are # of presses followed by a hold (H) or a release (C). So, “1C” is one click and release. “2H” is two clicks but you hold down the last one.
| State | Action | Result |
|---|---|---|
| Off | 1C | On (mode memory, mostly*) |
| Off | 1H (short) | Moonlight (memorized) |
| Off | 1H (long) | Lockout |
| Lockout | 1C | Battery indicator glows red |
| Lockout | 1H (long) | Unlock (to Moonlight) |
| Any | 3C | Strobe |
| Any | 2C | Turbo (not memorized) |
| Turbo | 2C | Return to previous mode (mostly* |
| On | 1H | Cycle mode (low-med-high) |
| On | 2H | Enable timer (and cycle between 3/9 minutes) |
UV UI is just 1C for on/off with only one mode, and that’s plenty. If you switch from UV to white while it’s on, it will return to the previously used white mode (mostly*).
What they got right:
- 1C on/off and 1H to cycle modes (this is the basis of most good UI’s)
- Dedicated shortcuts for Moonlight, Turbo, and Strobe that provide quick access. It’s great that they are shared with most other manufacturers so there’s no learning curve when switching lights.
- 5 brightness levels (having more is cumbersome in a small light like this)
- Turbo isn’t memorized. It has a dedicated shortcut so it doesn’t need to be memorized and using it won’t over-ride your memorized mode.
- The timer function is handy and it’s well hidden so casual users won’t stumble upon it and be confused.
- 2C from Turbo returns to the previously used mode*. That’s really handy and I missed that feature on Baton 3.
What they got wrong (all minor nitpicks):
- * High Mode Memory: If you turn it off High mode and then wait a few minutes it will forget the mode memory and go to Medium the next time you turn it on. I really don’t like this because I want High mode to be memorized but it forgets and turns on in Medium. Medium & Low modes are memorized normally.
- Moonlight is memorized and it should not be. There’s a dedicated shortcut for Moonlight so you can always access it when needed without relying on memory. As it is, accessing moonlight will override your memorized mode.
- Lockout: 1H to escape lockout is too easily done by accident when a light is in a bag or pocket. Lockout should require multiple clicks to unlock. A few other manufacturers are using 4 clicks to unlock and that works well.
Emitters & Beam
Olight is using undisclosed LED’s in Arkfeld UV. I wish they were more open with that information. The white LED is available in cool white or neutral white and I’m glad there are options! It’d be nice if the neutral LED was high-CRI and nice-tinted (negative DUV) though.
The white beam is very floody, even more than the original Arkfeld. That’s because the UV side takes up more space than the laser did, so the white side has a smaller optic. I found that it’s fine for indoors but it lacks enough throw for use outdoors.
In the beamshots below, the basketball goal to the right of the hotspot is 39M away and the pole in the power pole in the center is 185M away.
UV
Arkfeld UV’s secondary mode is ultra-violet. It makes some materials glow brightly and can be used for a variety of things from checking for counterfeit currency to charging glow-in-the-dark items. Olight advertises this emitter at 365nm which is ideal. For prolonged use I recommend buying some cheap polycarbonate safety goggles to protect your eyes. For more information on UV safety and use cases, check out this BrokenRecordBot entry I helped write.
Olight’s implimentation of a secondary UV light here is much more useful than most. There are many keychain lights available now that have a UV LED on the side, but those typically aren’t very bright, aren’t focused at all, and sometime shine through plastic that partially blocks UV. Arkfeld UV has none of those problems and produces a very usable UV beam. My only gripe is I wish there were a ZWB2 filter installed over the LED.
ZBW2 filters block all visible wavelengths (that’s why they appear black) and only let UV light through. UV LED’s still emit a small amount of visible light so blocking that can increase the contrast between objects that glow and objects that don’t. It basically makes glowy objects appear to glow brighter. Below is an example from my Convoy S12 UV review of UV light with and without a ZWB2 filter.
Mode Chart
Disclaimer: All of my measurements are taken at turn-on. Lumen measurements were taken on a Texas Ace 3.5″ Lumen Tube. A candela measurement was taken at 10 meters with an Opple Light Master III on the highest brightness, and other candela figures were calculated relative to that. CRI, CCT, & DUV data was taken for each mode from a few feet away at the center of the hotspot with the Opple Light Master and Waveform DUV Calculator. Runtime tests were performed with the Ceilingbounce app on my smartphone. All of these tests were performed with a fully charged battery unless otherwise specified. I cannot measure moonlight directly, so moonlight readings are calculated based on the brightness relative to the next-lowest mode. None of this is professional equipment, so take all of these measurements with a grain of salt.
Above are the official specs, followed by my own measurements below.
| Level | Lumens | Candela | Throw (Meters) | CRI (Ra) | Color Temp. (K) | DUV (Tint) |
| Turbo | 890 | 2200 | 94 | 66 | 4700 | 0.0074 |
| High | 265 | 655 | 51 | 65 | 4720 | 0.0095 |
| Medium | 52 | 129 | 23 | 65 | 4600 | 0.0091 |
| Low | 11 | 27 | 10 | 64 | 4590 | 0.0100 |
| Moonlight | 0.8 | N/A | N/A | N/A | N/A | N/A |
How does it compare to the official specs? Close enough. Lumens measured a little low and candela measured a little high. I’m not using professional grade equipment so anything within ~15% of advertised is close enough for me.
Moonlight: This light is pretty good at 0.8lm. I find that ~0.5lm is just right for moonlight. 0.1lm and below is too dim to be useful and above 1.0lm is too bright for some situations.
Mode Spacing: is good. There are no weirdly small or large jumps.
Runtime
Performance: is good overall. Three minutes before stepdown on Turbo is particularly excellent in this size range. All modes have a respectable runtime. Unfortunately my regulation testing in the next section revealed and issue with Turbo mode.
UV Runtime: I didn’t graph it but I did a UV runtime test and it ran fairly flat (with some variation up and down ~10%) for just shy of four hours. That’s excellent.
Thermal regulation: The cooled and un-cooled Turbo runtime tests are identical, which means this light has zero thermal active thermal regulation. It’s just a 1-minute timed stepdown from Turbo to High and that’s it. That makes it very predictable but it also means it’s possible for it to overheat in adverse conditions or to leave some performance on the table in ideal conditions.
LVP (Low Voltage Protection): Unable to measure due to built in battery.
Driver & Regulation
I’m fairly certain this light uses a 3V white emitter and a li-po battery. Based on that and its performance I’m guessing it’s using a high efficiency buck driver. That’s just a guess though as I was unable to disassemble the light and have no knowledge of its specific internals parts. I’m not sure if there’s a different drive circuit for the UV emitter.
White light regulation is quite poor. I found that Turbo is only reliably accessible with four bars of battery. I was able to use it occasionally with three bars but only when it had just changed from four to three bars. High mode is only accessible with two bars or more. From a manufacturer with Olight’s pedigree I expected Turbo to work down to two bars or less and for High mode to work down to one bare or less. This is basically a 250lm light that can sometimes boost up to 1000 when it’s fresh off the charger.
UV Regulation: Is quite good. I didn’t do a dedicated UV regulation test but I did a runtime test and it ran fairly flat (with some variation up and down ~10%) for just shy of four hours. That’s excellent.
Note: All regulation measurements are taken at turn-on so they do not reflect any thermal or low voltage stepdowns that may occur. A value of 0 indicates low voltage shutoff immediately upon activation.
PWM: No PWM is visible to my eyes or camera, nor audible to my ears.
Parasitic Drain: Unable to measure due to built in battery.
Switch
Arkfeld UV has two switches: a button and a rotary toggle. The button controls on/off and mode selection. The rotary toggle controls which LED is selected. The button is audible (unlike my original Arkfeld) with a deeper tone than most side e-switches. It’s fine but nothing special. The rotary toggle is a delight. It’s got a snappy and audible action that’s fun to flip back and forth. It’s possible to feel what position it’s in without looking at it, which is nice. I’m delighted that Olight added a separate switch for selecting the LED instead of putting an extra click-hold combo into the UI. That’s gotten old on my dual-channel lights running Anduril 2.
Carry & Ergonomics
Arkfeld UV’s ergonomics are excellent. It fits nicely in the hand just like a small TV remote control. My thumb lands naturally on the button in a forward grip. I can also hold and use it in a pencil-ish grip with my index finger on the button. The extra milling on the side adds a little bit more grip but is not aggressive.
Arkfeld UV carries even better than the original Arkfeld. Olight (almost) removed the flare at the tail and the clip has been swapped to a new bidirectional deep carry clip. It carries a lot deeper in the pocket and feels even less bulky with the tail flare (almost) removed. It also allows you to clip the light to the brim of a hat and use it as a headlamp. This new clip is one of my favorite changes they made.
Unfortunately Olight is still using permanent threadlocker on the screws so the clip is not user serviceable. They even told me that Arkfeld UV uses an even stronger compound than Arkfeld. I’m very disappointed in Olight for this decision. Every pocket clip should be user serviceable, especially bidirectional clips because they are more likely to get snagged on something and bend or break. I hope in the future they will move to temporary thread locker and sell replacement clips. Below is what they said when I broke the clip on my original Arkfeld:
If you accidentally break the pocket clip on your Arkfeld within 30 days of purchase, Olight will exchange your light for a new one at no charge. If you accidentally break the pocket clip on your Arkfeld past 30 days from purchase, Olight will exchange your light for a new one but you must pay return shipping on your broken light.
Tailstand: works fine and is stable enough for most situations
Magnet: not super strong but is strong enough to hold the light up on a vertical surface
Batteries & Charging
The battery is built-in and is not user accessible. That’s what allows Arkfeld to be so narrow and sleek, but it also means it has a limited lifespan. There are four battery indicator LED’s below the switch that light up to show battery status for a short time after the button is pressed.
Charging is facilitated by an included magnetic charging cable. It’s proprietary and it’s the only way to charge the light since the battery is built in. It’s tremendously convenient if you leave it in one place though, because you can just wave the tail of the light near the charging puck and it will connect. While charging the LED indicator on the puck glows red. When charging is complete, it glows green. The light will work while charging.
Charge status is indicated by four LED’s below the selector ring. I love this indication system as it’s extremely clear, precise, and doesn’t require any extra user input. Some lights use a series of clicks and holds to enter a battery check mode that blinks out the voltage or does a number of blinks to tell battery status, but that’s pretty ambiguous and isn’t glanceable. This solution with LED indicator bars under the switch is perfect. Anyone can pick up the light, turn it on, and immediately understand what the bars mean.
Competition
Here are some lights in the same class and how they compare.
Olight Arkfeld: Almost identical besides a different pocket clip and a laser instead of UV
Surefire Stilletto: Profoundly unattractive design, very expensive, standard USB charging, dedicated turbo tail switch, no magnetic tailcap, no UV
Streamlight Wedge: narrower and longer, even more sleek than Arkfeld, looks like an OTF knife, does not flare at the tail, has standard USB-C charging port but it’s exposed so debris can get in, unique lever switch, poor UI for EDC (only two modes, lowest 300lm), no magnetic tailcap, similar price point, supports common aftermarket pocket knife clips, no UV
This section is not comprehensive. If I didn’t include a particular light here, it doesn’t mean it’s bad or doesn’t deserve to be here. I simply cannot list every possible competitor.
Conclusion
Arkfeld UV is a good expansion of Olight’s Arkfeld line. Its white light performance is somewhat dissapointing but the UV implimentation is the best I’ve seen in an EDC light and the flat rectangle shape makes it a joy to carry. Plus, it includes all the other Olight perks like handy magnetic charging, a magnetic tailcap, great build quality, and a good UI. If you need your EDC light to have a great secondary UV mode, this is the light to buy.
Thanks to Olight for sending me this light for review!
