Let’s dive into the Fireflylite X4Q Comet, featuring the FFL351A 3700K emitter. I will cover a bit more than just runtimes today. Purchased in November 2024, it was my first Fireflylite and my introduction to the Lume X1 driver. Let’s see how it holds up!
The contender
Let’s put this light onto the balance before stepping on the ring
Sorry: not the greatest contrast. Reading 72g without battery here.
Beam shots
For an everyday carry light, I usually prefer a reflector over a TIR optic. It’s not a dealbreaker, just a personal preference. That said, I have to admit the X4Q’s 15° clear optic, paired with these emitters, performs impressively—almost mimicking a reflector beam profile.
Light Output Measurements
| CCT | DUV | Candela | Throw (meter) | |
|---|---|---|---|---|
| Level 1 | N/A | N/A | N/A | N/A |
| Level 2 | 3831 | -0,0022 | N/A | N/A |
| Level 3 | 3912 | -0,0027 | 273 | 33 |
| Level 4 | 3936 | -0,0028 | 1364 | 74 |
| Level 5 | 3912 | -0,0022 | 3844 | 124 |
| Level 6 | 3947 | -0,0018 | 8209 | 181 |
| Level 7 | 3954 | -0,0030 | 12921 | 227 |
Runtimes
- The Anduril’s ramp style was set to 7 steps ranging from 1 to 150.
- I tested level 4, 5, 6 and 7 with a thermal ceiling set to 55°C.
- Cell used:
- Two 21700 Samsung 50S (one at a time
). Note that these are not brand-new, so capacity have changed over time. Both measured at ~4650 mAh. - 1x brand-new Molicel P30B to compare with a 18650 light.
- Two 21700 Samsung 50S (one at a time
For each level where thermal regulation kicked in, I ran a second test under cooling conditions using compressed air.
All tests were conducted in a rudimentary amateur setup, utilizing a shoebox, a cellphone and Zak Wilson’s Ceiling bounce app. I used an array of lights to calibrate the shoe box. Although, I am very happy with the results and get consistent results with other top reviewers, please don’t take these numbers as the absolute truth.
Level 7/7
Level 6/7
Level 5/7
Level 4/7
I added two bonus runtime tests to compare with my beloved SC600w Mk IV Plus XHP50.2 4500K. For these, I used a Molicel P30B in both lights, with an adapter for the X4Q, of course.
This comparison is just for fun—stacking a 4500K light against a 3700K one isn’t exactly fair, as the emitters are fundamentally different. That said, the SC600w remains the most efficient 18650 light I own, and I have yet to find a true match for it.
Level 138/150 is the closest I found to the Zebralight SC600w max level which is level 12
I also matched a “medium” level. I found level 79/150 to be fairly close to ZL level 9.
Conclusion
The Lume X1 impressed me across all levels. Initially, I assumed— based on absolutely nothing —that it would deliver perfectly flat regulated output, but I was wrong. Instead, it maintains around 85% of its initial brightness, which is quite respectable. Even at the highest setting, the output remains impressively stable—though at this point, “turbo” might not be the right word anymore…
Overall, the X4Q delivers solid performance, and the combination of the 15° clear optic and FFL351A emitters makes for a compelling package. It’s a great addition to my collection, and I’m looking forward to seeing how it holds up over time.
Cheers !
