Sofirn HS21 Headlamp Review
The Sofirn HS21 headlamp has spot, flood, and red LEDs, selectable by a rotary interface. It uses an 18650, rechargeable by USB-C! Check out the infrared sensor!
Official Specs and Features
Here’s a link to the Sofirn HS21 headlamp product page.
Versions
There’s just one version of the Sofirn HS21 headlamp.
Price
The Sofirn HS21 headlamp sells for $45.99 on Sofirn’s website.
HS21 code: 10BB9D1C
Please use my Amazon referral link for the Sofirn HS21 headlamp (not sure the coupon will work if you don’t!). The discount is valid until November 20th and can be used with the discount on the page for a total of 30% off. Should be around $37 after code, I believe.
What’s Included
- Sofirn HS21 headlamp
- Sofirn 3000mAh 18650
- Charging cable
- Headband
- Spare o-rings (2)
- Manual
Package and Manual
Build Quality and Disassembly
The Sofirn HS21 headlamp is what Sofirn calls a “T-Shaped” headlamp! The build quality is great. Sofirn has the HS21 headlamp at around $46 but I’ve seen it down to $28 (aliexpress). For that price, it’s a ridiculous value!
Both the head and tail have springs.
These threads are very smooth and the tailcap has a nice big spring.
Size and Comps
Size: 35.7mm x 45.75mm x 86.5mm
Weight: 87g (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+. The version below is a custom laser-engraved Convoy S2+ host by GadgetConnections.com. I did a full post on an engraved orange host right here! Or go straight to GadgetConnections.com to buy your Convoy S2+ now!
Also above is the light beside a 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 HS21 headlamp is strictly a headlamp. There’s no pocket clip or magnet or anything else. The headband does use the newer-style clip-in system though. That’s greatly appreciated, and very functional.
I like this better because there are no silicone loops to fool with!
The back of this headband is cloth and comfortable enough.
Due to the T-shape of this headlamp, you’ll probably want to leave the over-the-head band in place.
Power and Runtime
The Sofirn HS21 headlamp is powered by a single lithium-ion cell. Sofirn includes a Sofirn branded 3000mAh 18650, which was used for all testing of this light. Since the light has springs on both ends, any type 18650 should work just fine.
The cell goes into the light with the positive end (button) toward the head. If you forget that, you can view the little icon near the tailcap.
There are six runtimes below. Four of those (the highest output four) can be seen in the first graph below.
The Sofirn HS21 headlamp does exhibit low voltage protection in every case.
When turning the light on, the switch indicates an approximate voltage for around 5 seconds, as follows:
Green: power level is 60-100%
Red: power level is 20-60%
Red flashing: power level is <20%
Charging
The Sofirn HS21 headlamp offers charging by way of a USB-C port in one tailcap section. The port has a press-in cover that’s easy to remove and replace.
On one side of the charging port is an indicator LED. In both photos above and below you can see two “extra” holes, too. Those are infrared sensors! This light can be controlled by waves!
A USB to USB-C cable is included.
Below you can see the indicator LED lit in red. When charging, the switch is red. When charging is complete, the switch goes to green.
Charging looks nice and quick for both A to C and C to C charging.
Modes and Currents
| Mode | Mode Claimed Output (lm) | Claimed Runtime | Measured Lumens | Tailcap Amps |
|---|---|---|---|---|
| Both – Turbo | 2200-1100 | 2m+90m | 1702 (0s) 1550 (30s) |
7.02 |
| Both – High | 1000-650 | 8m+150m | 844 (0s) 829 (30s) |
2.26 |
| Both – Medium | 400 | 3.5h | 350 | 0.79 |
| Both – Low | 100 | 12.5h | 89 | 0.19 |
| Both – Moonlight | 2 | 250h | 1.6 | [low] |
| Spot – Turbo | 2000-1000 | 2m+90m | 1326 (0s) 1263 (30s) |
5.45 |
| Spot – High | 1000-800 | 10m+90m | 756 (0s) 739 (30s) |
1.85 |
| Spot – Medium | 400 | 6h | 313 | 0.61 |
| Spot – Low | 50 | 37h | 39 | 0.05 |
| Spot – Moonlight | 2 | 350h | 1.6 | [low] |
| Flood – Turbo | 1200-500 | 2m+140m | 915 (0s) 862 (30s) |
3.72 |
| Flood – High | 500 | 2h25m | 380 (0s) 375 (30s) |
1.13 |
| Flood – Medium | 150 | 10h | 111 | 0.28 |
| Flood – Low | 30 | 45h | 21 | 0.05 |
| Flood – Moonlight | 2 | 250h | 1.5 | [low] |
| Red – Turbo | 100 | 5h | – | 0.55 |
| Red – High | 50 | 12.5h | – | 0.20 |
| Red – Medium | 20 | 29h | – | 0.07 |
| Red – Low | 2 | 250h | – | [low] |
| Red – Moonlight | 0.5 | 425h | – | [low] |
Pulse Width Modulation
None of the modes use 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 HS21 headlamp uses an e-switch on the head. This switch is domed and smooth and has an indicating LED underneath.
Below you can see the switch indicating in green.
Here’s a user interface table! The rotary selector can be moved while the light is on and the user interface is the same for any output selected. The selector also has mode memory! So if you are in moonlight of flood but left spot in turbo, if you rotate to spot while the light is on, you’ll get turbo!
| State | Action | Result |
|---|---|---|
| Off | Click | On |
| On | Click | Off |
| Off | Hold | Moonlight |
| On | Hold | Mode advance (LMHT) |
| Off | Double Click | Lockout (blinks red twice) |
| Lockout | Any action | Blinks red twice to indicate lockout |
| Lockout | Double click | Unlock |
| Red on | Double click | Slow red flash |
| Slow red flash | Click | Back to previous red state |
| On | Click 3x | Iterate infrared sensors on/off |
| Infrared on | “Wave (toward right side)”^ | Mode advance (LMHT) |
| Infrared on | “Stay 3s (towards right side)”^ (This means “cover the sensor for 3s.) |
Off |
^ What “toward right side” means here is the sensor is on the right side of the light. Your actions will be a wave as if you wave past your right ear, and not in front of the light itself.
LED and Beam
The Sofirn HS21 headlamp uses 1 SFT40 6000K-6500K LED (for spot), 6 CSP1919 5000K LEDs (for flood) and 3 HFL1-R red LEDs.
Both spot and flood can be used at the same time, too. Interestingly, the spot emitter is very much brighter than the flood emitters, so in the “both” output, it somewhat overwhelms the flood.
LED Color Report (CRI and CCT)
Together, the Luminus SFT-40 spot emitter and CSP1919 5000K LEDs (top row) are cool white and low CRI. No surprise because of how powerful the spot emitter is. Next is the flood emitters alone, which are around 5000K (as claimed) and very high CRI! Finally, the spot emitter alone mimics the “both” charts.
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.
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. These photos are taken around 18 inches from the door.
I compare everything to the KillzoneFlashlights.com 219b BLF-348 because it’s inexpensive and has the best tint!
Summary and Conclusion
For the price, it’s hard to beat the Sofirn HS21 headlamp. I love that the user interface matches across all output selections (on the rotary). That’s a plus, and it also means we have ample red mode selections. Low is pleasantly low for all modes. The flood output is high CRI – another bonus. I appreciate the infrared wave feature but it’s not something I’ll likely use much. Fortunately, it doesn’t seem like we’re really paying a premium for that added feature.
The Big Table
| Sofirn HS21 headlamp | |
|---|---|
| Emitter: | Both (Luminus SFT-40 and CSP1919 (6)) |
| Price in USD at publication time: | $45.99 |
| Cell: | 1×18650 |
| Turbo Runtime Graph | High Runtime Graph |
| LVP? | Yes |
| Switch Type: | E-Switch |
| Quiescent Current (mA): | ? |
| On-Board Charging? | Yes |
| Charge Port Type: | USB-C |
| Charge Graph | |
| Power off Charge Port | All modes |
| Claimed Lumens (lm) | 2200 |
| Measured Lumens (at 30s) | 1550 (70.5% of claim)^ |
| Candela per Lumen | 5.99 |
| Claimed Throw (m) | 226 |
| Candela (Calculated) in cd (at 30s) | 407lux @ 5.31m = 11476cd |
| Throw (Calculated) (m) | 214.3 (94.8% of claim)^ |
| Claimed CCT | – |
| Measured CCT Range (K) | 5700-6400 Kelvin |
| Item provided for review by: | Sofirn |
| All my Sofirn reviews! | |
| Sofirn HS21 headlamp | |
|---|---|
| Emitter: | Spot (Luminus SFT-40) |
| Turbo Runtime Graph | High Runtime Graph |
| LVP? | Yes |
| Claimed Lumens (lm) | 2000 |
| Measured Lumens (at 30s) | 1263 (63.2% of claim)^ |
| Candela per Lumen | 12.61 |
| Claimed Throw (m) | 230 |
| Candela (Calculated) in cd (at 30s) | 440lux @ 6.001m = 15845cd |
| Throw (Calculated) (m) | 251.8 (109.5% of claim)^ |
| Claimed CCT | 6000-6500 |
| Measured CCT Range (K) | 6000-6900 Kelvin |
| Item provided for review by: | Sofirn |
| All my Sofirn reviews! | |
| Sofirn HS21 headlamp | |
|---|---|
| Emitter: | Flood (CSP1919 (6)) |
| Turbo Runtime Graph | High Runtime Graph |
| LVP? | Yes |
| Claimed Lumens (lm) | 1200 |
| Measured Lumens (at 30s) | 862 (71.8% of claim)^ |
| Candela per Lumen | 1.84 |
| Claimed Throw (m) | 63 |
| Candela (Calculated) in cd (at 30s) | 80lux @ 4.856m = 1886cd |
| Throw (Calculated) (m) | 86.9 (137.9% of claim)^ |
| Claimed CCT | 5000 |
| Measured CCT Range (K) | 4800-5200 Kelvin |
| 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 I like
- User interface matches for all output selections
- Good selection of (5) modes for each output
- Both white emitters can be used together
- USB-C charging
- High CRI on the flood emitters
- Infrared wave output selection
What I don’t like
- Cool white, low CRI spot emitter
- Just generally the shape – the head is so big!
Notes
- This content originally appeared at zeroair.org. Please visit there for the best experience!
- For flashlight-related patches, stickers, and gear, head over to PhotonPhreaks.com!
- Please use my amazon.com referral link to help support zeroair.org!
- Please support me on Patreon! I deeply appreciate your support!
