Sofirn HS41 Headlamp Review
The Sofirn HS41 headlamp is a rechargeable light using a 21700, four Luminus SST-40 emitters, and an indicating e-switch. It is available in neutral and cool white.
Official Specs and Features
Here’s a link to the Sofirn HS41 rechargeable headlamp product page.
Versions
There’s only one version but it’s available in 5000K and 6500K and also with or without a 21700.
Price
Without the cell, the Sofirn HS41 rechargeable headlamp sells for $22.99. The cell adds just $3 and is a great deal.
Short Review
The Sofirn HS41 rechargeable is a fine headlamp, if a little large for headlamp usage. It’s a great right-angle light either way, though. I like quad-emitter lights and quad-emitter headlamps are not all too common. While I appreciate the high output from this 6500K version, I think the 5000K version will be more suitable for most people. At $23, I honestly don’t even know how they make these lights. It’s great quality, especially at $23.
Long Review
The Big Table
| Sofirn HS41 rechargeable headlamp | |
|---|---|
| Emitter: | Luminus SST-20 (Quad) |
| Price in USD at publication time: | $22.99 |
| Cell: | 1×21700 |
| Runtime Graphs | |
| LVP? | Yes |
| Switch Type: | E-Switch |
| Quiescent Current (mA): | ? |
| On-Board Charging? | Yes |
| Charge Port Type: | USB-C |
| Charge Graph | |
| Power off Charge Port | with cell: all modes without cell and/or body: no modes |
| Claimed Lumens (lm) | 4000 |
| Measured Lumens (at 30s) | 2011 (50.3% of claim)^ |
| Candela per Lumen | 6.78 |
| Claimed Throw (m) | 325 |
| Candela (Calculated) in cd (at 30s) | 738lux @ 4.953m = 18105cd |
| Throw (Calculated) (m) | 269.1 (82.8% of claim)^ |
| Claimed CCT | 6000-6500 |
| Measured CCT Range (K) | |
| Item provided for review by: | Sofirn |
| All my Sofirn reviews! | |
^ Measurement disclaimer: Testing flashlights is my hobby. I use hobbyist-level equipment for testing, including some I made myself. Try not to get buried in the details of manufacturer specifications versus measurements recorded here; A certain amount of difference (say, 10 or 15%) is perfectly reasonable.
What’s Included
- Sofirn HS41 rechargeable headlamp
- Sofirn 5000mAh 21700
- Charging cable (USB to USB-C)
- Spare o-rings (2)
- Headband
- Manual etc
Package and Manual
Build Quality and Disassembly
As I said above, the Sofirn HS41 rechargeable headlamp is a great light, but maybe a touch big for headlamp usage. It’s great as a right-angle light too, though, and that’s how I’d suggest you plan on using this one. The build quality is great. I am simply amazed that this light costs only $23!!
The head has just a button, but the tail has a spring. There’s a magnet in there too, but I don’t know that the spring can be removed for magnet access.
Here’s the cell tube. It appears reversible. Regardless of that though, the pocket clip can go on either end.
Size and Comps
Size: 30.1mm x 29mm x 115mm
Weight: 79g without battery
If the flashlight will headstand, I’ll show it here (usually the third photo). If the flashlight will tailstand, I’ll also show that (usually in 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 above 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. I also reviewed that specific edition, the “Oveready BOSS FT Collector Vintage Brass” 35. I love it!
Retention and Carry
The Sofirn HS41 rechargeable headlamp attaches to the included headband through these two silicone loops seen below.
They’re grippy enough and hold the light securely, but do allow rotation.
There’s a top band too, so the light is secured over the head as well. This top band is not (temporarily) removable. It could be cut off, of course.
The pocket clip can’t really be used while the light is in its headband.
Also included with the Sofirn HS41 rechargeable headlamp package is this two-way pocket clip.
It’s a fine clip and can attach on either end of the cell tube.
On the shoulder of the pocket clip is a hole suitable for lanyard attachment. A lanyard is not included.
A magnet in the tailcap is perfectly capable of holding the HS41.
Power and Runtime
If you buy the kit (and you should), a Sofirn-branded 5000mAh 21700 is included.
That cell goes into the light in the usual way – positive end toward the head.
There’s a little icon on the tail in case you forget that information.
Below are a few runtime tests. Even at startup, I’m only seeing 3300 lumens (fairly short of the claimed 4000 lumens). Still, that’s very high output for a light this small, and even if it was hitting 4000 lumens, that wouldn’t be maintained for long (and that’s what we observe).
When the cell voltage gets low, not only does the switch blink in red, but the light also vibrates. That’s quite an unusual feature to have on any light, much less a light that costs only $23! I personally don’t care about the vibrate feature (the switch light is enough) but it’s still fairly well implemented (it buzzes around once a minute when voltage is low).
The switch indicates voltage as follows:
Green: power level is 70-100%
Red: power level is 30-69%
Red flashing: power level is <30%
Charging
The Sofirn HS41 rechargeable headlamp offers charging by way of a USB-C port in the head. The port has a press-in cover that’s easy to remove and replace.
A USB to USB-C cable is included.
Charging looks nice and quick, but does seem to have some inexplicable inconsistencies. I wouldn’t say they’re bad necessarily though, and either way charging is done in around 2 hours.
Modes and Currents
| Mode | Mode Claimed Output (lm) | Claimed Runtime | Measured Lumens | Tailcap Amps |
|---|---|---|---|---|
| Turbo | 4000 | 3h | 3290 (0s) 2011 (30s) |
14.09 |
| High | 1500 | 3h10m | 1468 | 3.12 |
| Medium | 500 | 3h40m | 463 | 1.29 |
| Low | 150 | 11h | 149 | 0.52 |
| Eco | 10 | 172h | 5.1 | 0.01 |
| Moonlight | 1 | 29.5d | 0.4 | [low] |
Pulse Width Modulation
Only Moonlight seems to avoid PWM – even Turbo seems modulated a bit by PWM! It’s all very fast though, so you’re unlikely to notice the PWM.
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
The Sofirn HS41 rechargeable headlamp uses an e-switch on the head. This switch has a knurled cover, as well as two indicating LEDs underneath.
Below, you can see the switch indicating in red. It can also indicate in green and flashing red.
Here’s a user interface table! This table is mainly for the stepped output options. The user interface also has a ramping option, which is pretty simple. Much of the information below also covers that group, too (like strobes and lockout).
| State | Action | Result |
|---|---|---|
| Off (Unlocked) | Click | On (Mode Memory) |
| Off (Unlocked) | Hold | Moonlight |
| On | Hold | Mode advance (Eco>Low>Medium) |
| On | Double click | High |
| High | Double click | Turbo (continued double clicks iterate High and Turbo) |
| Any (Unlocked) | Click 3x | Strobe |
| Strobe | Hold | Strobe advance (Strobe>SOS>Beacon) |
| Strobe | Click | Off (The manual has this wrong – it says a click will put you in the previous mode.) |
| Off (Unlocked) | Click 4x | Lockout (light blinks twice to indicate) |
| Lockout | Click 4x | Unlock and on in mode memory |
| Lockout | Click | Main emitter blinks twice (side indicator doesn’t do anything) |
| Lockout | Hold | Momentary Moonlight |
| On | Click 4x | Iterate stepped and ramping output |
LED and Beam
Sofirn uses for emitters in the HS41. They’re all Luminus SST-20, but available in either 6500K or 5000K. What I have here is 6500K. This cooler white version should have higher output than the 5000K version.
LED Color Report (CRI and CCT)
CCT actually stays right around 6000K, which is good, but that’s still very cool white. The CRI is also very low, at under 70.
Beamshots
These beamshots always have 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.
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.
I compare everything to the KillzoneFlashlights.com 219b BLF-348 because it’s inexpensive and has the best tint!
Conclusion
What I like
- Very low cost
- Good user interface
- Interesting use of vibration feature
- USB-C charging
- Complete package (add cell for just $3)
- Ramping option for those who want it
What I don’t like
- Big for a “headlamp” (great for “right-angle”)
- Very cool white (and also very low CRI)
- Double click twice to get to Turbo is annoying
Notes
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