Sofirn LT1S Lantern Review
The Sofirn LT1S is a lantern that runs on a single 21700 (included) and has ramping from warm to cool white, and red! Also: USB-C charging!
Official Specs and Features
Here’s a link to the Sofirn LT1S lantern product page.
Versions
There’s really just one “version” of the Sofirn LT1S lantern, but many colors are available. Even orange…
Price
The going price for the Sofirn LT1S lantern is $45.59. You can add the 21700 cell seen in this review for another $5, and you should just go ahead and do that!
Short Review
I enjoy lanterns and I have a few, but I’m not a lantern collector. I will say that among the lanterns I have, this one is among my favorites – I love that it uses a single cell. I love that it can ramp from (very) warm to cool white and that there is a separate red option. All in all, I’d say this is a good lantern option.
Long Review
What’s Included
- Sofirn LT1S lantern
- Sofirn 5000mAh 21700
- Charging cable (USB to USB-C)
- Spare o-rings (2)
- Manual
Package and Manual
Build Quality and Disassembly
The build quality is here. Unlike a lantern by, say, Olight, the LT1S has more corners and is less rounded, but that also makes it a bit more “flashlight-like.”
The top has a switch, four charge indicators, and a USB-C charging port.
The bottom doesn’t have anything!
Both head and tail have a nice big spring.
Size and Comps
97mm x 68mm
257g (without cell)
If the flashlight will headstand, I’ll show it here (usually the third photo). If the flashlight will tailstand, I’ll show that here, too (usually the fourth photo).
Here’s the test light with the venerable Convoy S2+. Mine’s a custom “baked” edition Nichia 219b triple. A very nice 18650 light.
Also seen is the light beside my custom engraved TorchLAB BOSS 35, an 18350 light. I reviewed the aluminum version of that light in both 35 and 70 formats.
Retention and Carry
As a lantern, the LT1S smartly has a beefy hanging loop on the top. This loop folds down or up easily and can fold to either side.
That’s it!
Power and Runtime
The Sofirn LT1S lantern is powered by a single lithium-ion battery. If you go for the package deal, you’ll get the 5000mAh 21700 seen below.
The cell goes into the LT1S with the positive end toward the top of the light.
Because the output is 360°, I’ve just recorded these levels as percentages.
Charging
The LT1S sports USB-C charging and the charging port is on the top. It’s covered with a press-in rubber cover.
An appropriate cable is included. It’s USB to USB-C.
Charging looks very good at nearly 3A! For a 5000mAh cell like the one that’s included, 3A is perfectly fine.
C to C charging works great, too!
Powerbank
The powerbank feature on the LT1S works great, too! I did a sort of “stress test” on the output – run at the highest level where it stays at around 5V until it shuts off, then repeat at the next lower level. The USB-C port can output over 3A at 5V, which is very good. After that shuts off, you can cycle the port and get 2A for a while, then 1A for a while. Just unplug/plug your device. Here are a couple of graphs!
Here’s the same data, but a 2-minute window from the early heavy test at 3A, to the point where output shuts off because of high current.
The powerbank does eventually shut off. At that point (in the graph above at 52 minutes or so), the cell voltage was 3.2V – perfectly respectable for cell protection.
Modes and Currents
| Mode | Mode Claimed Output (lm) | Claimed Runtime | Measured Lumens | Tailcap Amps |
|---|---|---|---|---|
| Turbo | 500 | 2h20m | – | Warm White: 2.24 Cool White: 2.19 |
| High | 150 | 6h | – | Warm White: 0.60 Cool White: 0.60 |
| Medium | 50 | 18h | – | Warm White: 0.21 Cool White: 0.21 |
| Low | 10 | 90h30m | – | Warm White: 0.06 Cool White: 0.06 |
| Moon | 1 | 555h | – | Warm White: 0.03 Cool White: 0.03 |
Pulse Width Modulation
It doesn’t seem like the LT1S uses PWM, but on the highest mode we can see just the tiniest bit of peaks showing. In any case, it’s nothing to worry about.
As seen below, the mode order is
Warm white: 5 (top row)
Cool white: 5 (middle row)
Red: 3 (bottom row)
This mode order will be followed throughout the rest of the review.
Here you can see a “baseline” – a chart with almost no light hitting the sensor.
Then there’s the Ultrafire WF-602C flashlight, which has some of the worst PWM I’ve seen. It’s so bad that I used a post about it to explain PWM! Here are multiple timescales (10ms, 5ms, 2ms, 1ms, 0.5ms, 0.2ms) to make comparing this “worst” PWM light to the test light easier. That post also explains why I didn’t test the WF-602C at the usual 50us scale.
User Interface and Operation
A single switch controls the Sofirn LT1S lantern. That e-switch is on the top of the lantern and is covered by a knurled rubber boot.
The action is fine and the sound is moderately clicky.
Here’s Sofirn’s graphic of the user interface.
Here’s a user interface table!
| State | Action | Result |
|---|---|---|
| Off | Hold | Moonlight (of memorized side and CCT) |
| On | Click+Hold | Tint Ramp |
| Off | Click | Memorized brightness (of memorized side and CCT) |
| Off | Click 2x | Turbo (of memorized side and CCT) |
| Any | Click 3x | Red output (Memorized level) |
| Red on | Hold | Red advance (LMH) |
| Red on | Click | Previous state |
| Red on | Click 2x | Red Strobe or Red SOS (Memory) |
| Red Strobe group | Click 2x | Iterate between Red Strobe and Red SOS |
| Red Strobe group | Click | Previous Red state |
| Red on | Click 3x | On in white (of memorized side and CCT) |
| On | Click | Off |
| On | Hold | Mode advance Stepped output: LMHT and cycles back to low Ramping output: Ramps in one direction and stops at that extreme (does not cycle back to the lower output and ramp more) |
| On | Click 2x | Cycle emitter sides: (One side (half) > the other half > both halves) |
| On | Click 4x | Iterate between Ramping and Stepped output |
LED and Beam
Sofirn uses “36 CSP1919 LED and 4 Red LED” emitters in the Sofirn LT1S lantern.
The tint ramp feature of this light is pretty neat, I’d say. You might not think you’d find it all that useful, but there are times when a bright white (cooler) CCT is welcome and distinct times I find that a very warm white CCT is welcome, too. Your mileage may vary, as they say!
LED Color Report (CRI and CCT)
I’ve tested the CCT for the extremes. First (top row) is the warm white, which comes in at around 2500K. Then (second row) the cool white, which reads around 5900K. Both are great for their purposes and have nice and high CRI!
I don’t think I grabbed CCT for the red, but I can if anyone needs to see just how red they are. 😀
Beamshots
These beamshots are always with the following settings: f8, ISO100, 0.3s shutter, and manual 5000K exposure. These photos are taken at floor level and the beam hits the ceiling around 9 feet away. As above: warm white in the top row. Cool white in the middle row. Red in the bottom row.
Tint vs BLF-348 (KillzoneFlashlights.com 219b version) (affiliate link)
I keep the test flashlight on the left, and the BLF-348 reference flashlight on the right. As above: warm white in the top row. Cool white in the middle row. Red in the bottom row.
I compare everything to the KillzoneFlashlights.com 219b BLF-348 because it’s inexpensive and has the best tint!
Conclusion
What I like
- Uses just one cell!
- Good user interface
- Has red
- Red has modes (and one of them is pleasantly low)
- Tint ramping is a very neat feature
- Tint ramping doesn’t really get in the way
- C to C charging works
What I don’t like
- No magnet in base
Notes
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