Olight ArkTac Ultra Review – The Point of Diminishing Returns

Pricing & Availability

Olight sent me this light in exchange for an honest review. Here is the official product page where you can see current pricing. Those are not affiliate links. At the time of writing it’s a whopping $160 USD for pre-order.

What comes in the box?

This light comes in one of Olight’s nice black “Ultra” series boxes. Inside is:

• The light itself
• User manual
• Magnetic USB-C charging cable

Design & Construction

ArkTac Ultra takes ArkPro Ultra’s overall design and adds more texture to the rotary selector, glass breakers in the bezel, two tail switches, and a new clip. It’s a smart-looking light overall, but I don’t particularly like the new clip.

Build quality is top notch. The fit and finish are perfect. All the moving parts feel precise. It’s made of Olight’s “OAL 2” alloy which they claim is stronger and more durable than standard aluminum alloys.

Size & Measurements

Surefire G2X pro + Switchback | Streamlight Microstream | ArkTac Ultra | Emisar D4KC | Mini Maglite

It’s a lot larger than I expected; similar in length and width to many cylindrical tactical/duty style lights. It’s not much lighter than my G2X pictured above either. It’s about half the thickness though, with less battery capacity.

Measurement	Measured (mm)
Length	135.9
Width	29.0
Thickness (not including clip)	16.9
Thickness (including clip)	20.9
Weight with included battery (g)	135

Switch & User Interface

There is a lot going on here. It’s a two-steps-forward, one-step-back situation. Let’s start with the five switches. New features are underlined.

• Main button: This is the e-switch in the center of the rotary selector. It turns the light on/off and changes brightness just like most lights. Excellent.
• Rotary selector: Around the main switch is a rotating ring that snaps into 3 different positions: White, UV, or Red. There are glowing indicators to show you which channel you’ve selected. It works great.
• Laser button: The square button on the side of the light is a dedicated switch for the laser. A click turns it on/off and a hold from off is momentary-on. Holding from on cycles between high and low power and is memorized. The laser can be turned on in combination with any of the other lights sources too. Top notch execution.
• Primary tail switch: A full-press activates Turbo mode and a half-press activates a configurable lower mode. A press-and-hold is momentary-on, and a press-and-release is constant-on. Nicely done, Olight!
• Red tail switch: This is a customizable switch that can do one of four things: Strobe, UV, Red, or Laser. Strobe is momentary-only but the other three options can be momentary with a long-press or constant-on with a short-press. Red or UV can only be assigned in their higher brightness level, not their lower brightness level. That seems like an oversight, as having a dedicated button for low-red light might be useful.

Here’s my Basic E-switch UI Checklist (main switch only). New features are underlined. Score: 10.5/12

• 1C on/off✅
• 1H to change brightness✅
• Stepped levels✅
• Main rotation is Low-Med-High✅
• Moonlight shortcut: 1H from off✅
• Low shortcut: 1H from Moonlight✅
• Turbo shortcut: 2C from anywhere✅
• Strobe shortcut: 3C from anywhere✅
• Mode memory for Low, Medium, and High✅
• No mode memory for Moonlight, Turbo, and Strobe✅/❌
  • Moonlight is not memorized! That’s a first for Olight and a significant improvement.
  • High mode stays memorized! Previous Olight models have “forgotten” high mode memory and reset to medium after a few minutes. This is a significant improvement.
  • Turbo is memorized as High mode just like previous models. That’s unintuitive and I wish it weren’t memorized at all. It’s easy to overlook in this model though because you can customize the tailswitch half-press brightness to whatever you want for quick access. Half point.
• 4C or separate switch to lock/unlock❌
  • It’s a long hold. That’s too easy to do/undo by accident.
• Does something when you click the switch in Lockout mode✅
  • The lockout indicator LED will glow. It will blink if the proximity sensor senses something when you try to turn on the light.

Notes:

• You can’t choose between spot and flood anymore. Turbo is spotlight. Everything else is flood. I don’t like the flood beam and I wish I could set it to spotlight all the time, even on lower modes. Seeing as this is a “tactical” light and the spot beam is so nice, I think the flood beam could be eliminated.
• The final version will be able to dim the spot beam temporarily according to this post. That’s slightly better than nothing, I suppose.
• You can select between fixed-frequency and variable-frequency strobe. To do so, hold the red switch and click the main side switch. This also acts as a trick to get constant-on strobe if you need it.
• There’s an SOS mode. Triple-click in red light mode to access it. It uses the red LEDs.

Emitter & Beam

There are five light sources here, and a new proximity sensor.

The spot beam (center reflector) is more of a balanced beam than a dedicated spot beam and I quite like it. The hotspot is round and crisp. The spill is also round and narrower than the floodlight spill. Once again there is no square corner shadow like previous Ark-series lights. I wish I could use this beam exclusively at all brightness levels. The LED is an Olight EIP-1

The flood beam (left frosted optic) quite floody with a diffused hotspot and spill. There’s no square corner shadow like on previous Ark-series lights. Personally, I find it too floody and wastes energy lighting up areas I don’t need, and requiring me to use a brighter mode to get the reach I want. I would not miss this flood beam if it were eliminated from the light entirely. This one might be an EIP-1 as well, but I’m not certain.

The red beam (two small frosted optics near the top) is quite floody and suitable for close-up use. It leans orange rather than being a true red, but I imagine it will suffice anywhere you need red light.

The UV beam (right reflector) is very similar to the spot beam with a crisp circular hotspot and narrow spill. It’s spill isn’t perfectly round but that matters little with UV. It works just fine but I wish it had a visible light filter like the ArkPro series does.

The laser beam (dark spot bottom left) is green and works as I expect. I like the new high/low power modes.

The proximity sensor (two bottom right dots) is an actual proximity sensor, not a bounceback sensor. It will stop the light turning on within 7cm of another object and will blink the lockout indicator. It doesn’t do anything if the light is already on before the sensor detects an obstruction. It works great.

In the beamshots below, camera settings are fixed and the wall is ~2.5M away.

In the beamshots below, camera settings are as similar as possible, the basketball goal to the right of the hotspot is 39M away, and the power pole in the center is 185M away.

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 were 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. These tests were performed with a fully charged included 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 these measurements with a grain of salt.

Level	Lumens	Candela	Throw (Meters)	CRI (Ra)	Color Temp. (K)	DUV (Tint)
Turbo	1800	14000	240	67	6220	0.0036
High	1200	1500	77	70	6340	-0.0010
Medium	180	225	30	69	5960	0.0018
Low	11	14	7	68	5840	0.0033
Moonlight	0.5	~1	~2	68	5790	0.0035

Runtime

Performance is good. Sustained brightness is a bit higher than ArkPro Ultra so it doesn’t run quite as long.

Thermal Management: My Turbo and Turbo Cooled tests are virtually identical, so there’s no active thermal throttling here, just timed stepdowns. That means performance will be consistent, but not optimized for ambient temperature.

LVP (Low Voltage Protection): When the battery is near-empty, the light will step down to Moonlight mode and run for a looong time (12-18hrs). Eventually it will turn itself off and won’t turn on again until you plug it in to charge.

Driver

The driver isn’t specified. Historically, Olight has used high-efficiency buck or boost drivers and that’s what I’d expect here too.

Voltage immunity is poor; not unusual for Olight. Turbo and High brightness is noticeably reduced below 50% charge, and even further at 25% charge. I think they program their lights to limit brightness to either extend battery life or battery health. Normally I expect near-full brightness to be accessible down to 25% charge. It’s worth noting that at low battery, “Turbo” mode still uses the Spotlight channel, just dimmer.

PWM: No PWM is visible to my eyes nor audible to my ears. My phone camera can detect some kind of flickering on Medium mode.

Parasitic Drain: I can’t measure parasitic drain because the battery is built in.

Batteries & Charging

The battery included is a 2050mAh cell. It’s not user-serviceable, so when the battery eventually wears out, you can’t replace it. That sucks, and it comes with the territory. Virtually all of these flat-style EDC lights have built-in batteries.

Charging is facilitated by a USB-C port on the side of the light with a metal cover, or by MCC magnetic charging contacts on the tail. It’s nice to have both options. An MCC charging cable is included in the box and it worked with the MCC cables I already have. Charging takes about 1:15 over USB-C. It works while charging, but max brightness is reduced. There’s no powerbank function, which is fine on a light this small.

Indicators

This light has the most indicator LEDs I’ve ever seen on a flashlight. There’s a battery indicator, brightness level indicator, lockout indicator, channel indicators, a power-saving indicator, and the “Arkbeat” RGB indicator. The battery, brightness, and channel indicators are all intuitive, glanceable, and just excellent.

The lockout indicator can be confusing because it also acts as a proximity indicator. Trying to turn on the light too close to an obstruction will make the lockout indicator blink. If you don’t know that, it’s confusing.

The “Arkbeat” RGB indicator is a gimmick. It does not need to be here, but it doesn’t get in the way. It changes color to indicate how long you’ve used the light, and eventually it lets you choose the color once you’ve “unlocked” it by letting the light run long enough. You can also disable it if you like.

Carry & Ergonomics

Ergonomics are excellent. It’s comfortable to hold and use the side switches in a forward grip. It’s comfortable to hold and use the tail switches in a reverse grip.

I saw someone online say the clip is interchangeable with ArkPro Ultra’s clip, but looking at them side by side I don’t think that’s the case. ArkPro Ultra’s clip footprint appears to be a bit smaller.

Magnet: The tail is magnetic like all Ark-series lights. It’s strong enough to hold the light up on a vertical surface.

Competition

Here are some lights in the same class and how they compare.

Olight ArkPro Ultra: The Reigning Champ

• lower price (still expensive)
• simpler UI (no tail switches)
• let’s you manually select spot or flood
• no red light
• better UV (has a visible light filter)
• a bit smaller and lighter
• lower profile bidirectional clip

Acebeam UC20: Budget Alternative

• less than half the price
• not as bright, similar throw
• better voltage immunity
• similar beam to the ArkPro’s spot beam that I really like
• mediocre UV and Red performance with no laser
• separate side and tail switches, no rotary selector
• user-accessible pouch-cell battery
• noticeably smaller and lighter weight
• more traditional bidirectional clip
• no proximity sensor, no magnetic tailcap

Jetbeam E26: Another Alternative

• significantly less expensive
• build wuality isn’t as nice
• side switch, tail switch, and rotary selector, but no laser button
• white light, laser, and UV. No separate floodlight nor red light channels
• UI has some quirks
• good beam profile, similar to ArkTac’s spotlight
• UV has a lot of visible light
• excellent voltage immunity
• no proximity sensor, better lockout (on the rotary selector)
• no magnetic tail

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

Ostensibly this should be an upgrade over ArkPro Ultra, but it’s got a major drawback. Olight has been adding more and more features and cost with every Ark-generation. I think they’ve reached the point of diminishing returns with ArkTac Ultra. It adds an excellent main tail switch, great proximity sensor, red light, glass breakers, a questionably-useful secondary tail switch, a weird pocket clip, and one major issue: you can’t select between spot/flood manually. ArkTac has spot beam that’s perfect for everything, but forces you to use the way-too-floody beam most of the time. With that issue, the sky-high price, and the built-in battery, this one is hard to recommend.

Thanks to Olight for sending me this light for review!