Sofirn HS42 Headlamp Review
The Sofirn HS42 headlamp features a throw emitter, three flood emitters, and red emitters, too! Bonus features include USB-C charging and an indicating switch.
Official Specs and Features
Here’s a link to the Sofirn HS42 headlamp product page.
Versions
There’s only one version of the Sofirn HS42 headlamp but you can buy with or without a 18650.
Price
Without the cell, the Sofirn HS42 headlamp sells for $33.99. The cell adds just $2 and is a great deal.
What’s Included
- Sofirn HS42 headlamp
- Sofirn 3000mAh 18650
- Charging cable (USB to USB-C)
- Spare o-rings (2)
- Headband
- Manual etc
Package and Manual
Build Quality and Disassembly
The Sofirn HS42 headlamp is a great headlamp! It’s great as a right-angle light too! The build quality is great. That this light costs only $33 is a win, too!
These threads are very smooth and the tailcap has a nice big spring.
Unlike some other Sofirn headlamps, this HS42 has a spring in the head, too!
Size and Comps
Size: 26mm x 27.2mm x 112mm
Weight: 71g (only headlamp 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 just 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
One of the nice updates to headlamp carry lately is that the attachment no longer has silicone loops. Those were fine, but this clip system is better.
The Sofirn HS42 headlamp slips in with a firm click into the usual two grooves.
There’s no pocket clip, but if you did find one that fit, you couldn’t use it and the headband at the same time.
The headband has a loop over the top too. It could be permanently removed, but not really removed off and on on the fly.
On the tailcap is a hole to attach a lanyard. A lanyard is not included, though.
The tailcap magnet is strong enough to hold this light.
Power and Runtime
The Sofirn HS42 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.
Below you can see output for three levels with both emitters and one spot. Output is around 1500 lumens, below the claim of 2100 lumens.
Here’s one test of Medium output with the spot emitter.
When turning the light on, the switch indicates an approximate voltage for around 5 seconds, as follows:
Green: power level is 70-100%
Red: power level is 30-69%
Red flashing: power level is <30%
Charging
The Sofirn HS42 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 for both A to C and C to C charging.
When charging, the switch is red. When charging is complete, the switch goes to green.
Modes and Currents
Mode | Mode Claimed Output (lm) | Claimed Runtime | Measured Lumens | Tailcap Amps |
---|---|---|---|---|
Turbo – Both | 2100 | 2h20m | 1578 (0s) 1458 (30s) |
5.53 |
High – Both | 900 | 3h30m | 638 (0s) 626 (30s) |
1.53 |
Medium – Both | 350 | 5h30m | 260 | 0.57 |
Low – Both | 50 | 21h | 40 | 0.08 |
Moonlight – Both | 1 | 300h | 0.27 | [low] |
Turbo – Spot | 2000 | 2h30m | 1251 | 4.85 |
High – Spot | 1000 | 2h40m | 725 | 1.74 |
Medium – Spot | 400 | 5h16m | 291 | 0.55 |
Low – Spot | 100 | 17h50m | 76 | 0.12 |
Moonlight- Spot | 1 | 460h | 0.15 | [low] |
Turbo – Flood | 1000 | 2h50m | 861 | 3.16 |
High – Flood | 450 | 4h20m | 353 | 0.88 |
Medium – Flood | 150 | 9h30m | 118 | 0.26 |
Low – Flood | 30 | 40h | 25 | 0.04 |
Moonlight- Flood | 1 | 480h | 0.24 | [low] |
Turbo – Red | 65 | 5h | – | 0.80 |
High – Red | 35 | 10h30m | – | 0.27 |
Medium – Red | 15 | 25h30m | – | 0.09 |
Low – Red | 2 | 125h | – | [low] |
Moonlight- Red | 1 | 270h | – | [low] |
Pulse Width Modulation
Only the red output (the second row) uses PWM. Any combination of the other emitters or modes doesn’t use PWM. Great!
For reference, here’s a baseline shot, with all the room lights off and almost nothing hitting the sensor. Also, here’s the light with the worst PWM I could find. I’m adding multiple timescales, comparing them to the test light will be easier. Unfortunately, the PWM on this light is so bad that it doesn’t even work with my normal scale, which is 50 microseconds (50us). 10ms. 5ms. 2ms. 1ms. 0.5ms. 0.2ms. In a display faster than 0.2ms or so, the on/off cycle is more than one screen, so it’d just (very incorrectly) look like a flat line. I wrote more about this Ultrafire WF-602C flashlight and briefly explained PWM.
User Interface and Operation
The Sofirn HS42 headlamp uses an e-switch on the head. This switch has a knurled cover, as well as indicating LEDs underneath.
Below, you can see the switch indicating in green. It can also indicate in red and flashing red.
Here’s a UI 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 (Low>Medium>High) |
On | Double click | Turbo |
Turbo | Click | Previous state |
Turbo | Double click | Flashing mode ( White Strobe) |
Strobe | Double Click | Red SOS (and switches memory to red (!!)) |
Either strobe | Click | Previous level (but not previous output)^ |
Off | Click 3x | White Strobe |
On | Click 3x | Emitter advance (Spotlight > Floodlight > Both > Red) |
Off | Click 4x | Lockout |
Lockout | Click 4x | Unlock to on state |
Lockout | Click | Blink twice to indicate lockout |
Lockout | Hold | Momentary Moonlight of memorized emitter |
^ There’s a weird corner case here where you can go from (for example) medium white output through (white) Strobe then red SOS and single click out of the red SOS to the “previous state” – the level is remembered but the emitters are not. You’ll end up in medium red in this case.
LED and Beam
The main emitter is a Luminus SST-40 at 6000K. It has a big TIR. You can just make out the two red emitters above that single Luminus. At the very top are three CSP2323 emitters. They’re warmer white, at around 5000K. More importantly, they’re higher CRI!
LED Color Report (CRI and CCT)
CRI for the warm white triple emitter output is a very pleasant neutral and high CRI. The Luminus higher output emitter is low CRI and a bit cooler. When they’re run together, the higher output emitter “wins” and so the overall profile is low CRI and cooler.
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
Sofirn is good at making headlamps, so it’s no surprise that this one is good. I really like the warm white emitters – 5000K and high CRI seems like a nice sweet spot. It’s nice that the red output gets the full host of (5) output levels. The user interface is simple and familiar and USB-C charging works great. All of that for around $35; this is a deal!
The Big Table
Sofirn HS42 headlamp | |
---|---|
Emitter: | Luminus SST-40 and CSP2323 x3 (both) |
Price in USD at publication time: | $35.99 |
Cell: | 1×18650 |
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: any output but just one (middle) without cell or tailcap: no modes |
Claimed Lumens (lm) | 2100 |
Measured Lumens (at 30s) | 1458 (69.4% of claim)^ |
Candela per Lumen | 4.09 |
Claimed Throw (m) | 176 |
Candela (Calculated) in cd (at 30s) | 260lux @ 5.339m = 7411cd |
Throw (Calculated) (m) | 172.2 (97.8% of claim)^ |
Claimed CCT | – |
Measured CCT Range (K) | 5500-5900 Kelvin |
Item provided for review by: | Sofirn |
All my Sofirn reviews! |
Sofirn HS42 headlamp | |
---|---|
Emitter: | Luminus SST-40 (throw) |
Claimed Lumens (lm) | 2000 |
Measured Lumens (at 30s) | 1251 (62.6% of claim)^ |
Candela per Lumen | 9.48 |
Claimed Throw (m) | 215 |
Candela (Calculated) in cd (at 30s) | 479lux @ 4.71m = 10626cd |
Throw (Calculated) (m) | 206.2 (95.9% of claim)^ |
Claimed CCT | 6000 |
Measured CCT Range (K) | 5400-6000 Kelvin |
Sofirn HS42 headlamp | |
---|---|
Emitter: | CSP2323 x3 (High CRI (Flood)) |
Claimed Lumens (lm) | 1000 |
Measured Lumens (at 30s) | 861 (86.1% of claim)^ |
Candela per Lumen | 1.26 |
Claimed Throw (m) | 63 |
Candela (Calculated) in cd (at 30s) | 89lux @ 3.554m = 1124cd |
Throw (Calculated) (m) | 67.1 (106.5% of claim)^ |
Claimed CCT | 5000 |
Measured CCT Range (K) | 5500-5900 Kelvin |
^ 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
- Good build quality
- Low cost
- Nice implementation of red emitters
- Neutral emitters have all 5 modes
- High CRI, neutral emitters
What I don’t like
- Low CRI main emitter
- Doesn’t hit output claims
Notes
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