Sofirn SP40 Headlamp

I was kindly offered the new Sofirn SP40 for review. I thank Sofirn for providing the light, and I promise to keep things honest and fair.

The SP40 is a brand new headlamp by Sofirn. This is their first “from the ground up” headlamp, and they did very well!

What I Like:

  • Bright, around 1233 lumens in turbo at turn-on
  • Neutral Cree XP-L LED: no Cree rainbow like from the recent flip-chips, and it even seems slightly warmer than my other Sofirns. It seems right around 5000K if I had to guess
  • Evenly spaced modes (as measured by myself): 12 lm ➙ 97 lm ➙ 536 lm ➙ 1233 lm
  • Thermal regulation
  • Relatively compact and light (59g without battery, without strap, with 18650 tube)
  • Good UI: click for on/off; hold to ramp up; double-click for turbo
  • Built-in micro-USB charing with indicator LEDs in the switch
  • Excellent kit: it includes a 18350 tube, a well-designed three-way strap, a pocket clip, and a charging cable
  • Pricing: at the time of this writing, it looks like the price will be $20-27 which seems extremely reasonable if not down-right cheap
  • Low-voltage cutoff kicked in at 2.85V
  • Built-in charging stopped at 4.18V
  • Low standby current, ~30uA

What Could Be Better:

  • I’d prefer Turbo to be in the normal UI rotation, not hidden behind a double-click
  • I’m sure not everyone wants this, but I’d love to be able to use the indicator LEDs as Aux LEDs while the light is off (and not charging)… it adds some style and makes it easier to find at night.
  • I find the button position to be a bit more awkward than if it were placed on the side
  • I wouldn’t mind the low mode being somewhat lower, perhaps 3 lm or so

Let me know if you have any questions I can answer!

Outdoor beauty shots:


Side-by-side with the Sofirn SP40 and Convoy H1:

Runtime Graphs:

Since I just got the SP40 and Convoy H1 around the same time, I feel like a few comparison notes are in order:

  • The SP40 is lighter than the Convoy H1 (59g vs 70g, respectively, without battery and without strap)
  • The SP40 is slightly brighter
  • The SP40 has micro-USB charging (nice convenience, but makes modding slightly more difficult)
  • The Convoy H1 lacks any kind of step down (in stock form) and get ridiculously hot
  • The Convoy H1 is very mod-friendly
  • The SP40’s “click for off” is much nicer than the H1’s “hold for off”, in my opinion
  • The SP40’s kit, overall, is a bit nicer: 18350 tube included, nicer strap
  • I like the H1’s button position better (on side vs on end)

Modding Info:

  • MCPCB: standard-ish 16mm
  • Reflector height: 7.9mm
  • Reflector width (outer): 17.1mm
  • Lens width: 19.5mm
  • Lens height: 1.1mm

The emitter is super easy to get to. Just unscrew the bezel, no glue. The MCPCB has thermal grease under it, not adhesive.

The reflector is nestled completely inside an o-ring and pressed to the glass. Theoretically you could remove the o-ring or use a smaller one if you wanted to fit a TIR with a larger diameter. Or even remove the glass if you needed additional height.

Thanks gchart for great review…definitely helpful insights for SOFIRN SP40.

Wow, that on turbo 1000lms it can handle 3 minutes before turn down at 4mins…and down to 500lm (50% output) is really nice…gheezz!!

Nice review gchart. Too bad it doesn’t have ultra low or moonlight mode. Still a great light for its price though. Does it atleast have direct access to the low mode from off (without having to cycle from memorized mode)? Long press from off maybe?


Long press from off sadly does nothing. Double click from off does go directly to turbo. No shortcut to low from off unless that’s what it has memorized.

Thanks for checking. Too bad. This could have been a great headlamp especially with the shorty tube. Are you able to access the emitter?

Yup, super easy. I just added some modding notes to the bottom of the first post with dimensions. I meant to reserve the second post for teardown and potential modding. Oops. :person_facepalming:

Yeah no moon mode :frowning:

Can u talk to Sofirn to convince them :slight_smile:

Thanks gchart!
If possible, please build a temperature graph starting in Hi-450Lm(536Lm) mode .

Thanks for the review! I was quite interested in this headlamp, but the lack of a Moon mode which is accessible from off is a real deal-killer, especially on a headlamp! What was Sofirn thinking? Headlamps are often used while camping/backpacking and those users know very well that predictable access to Moon mode is a must.

12lm on Low is not so bad, but it can’t be reliably accessed from off! If I owned this light, I would have to always set it back to Low before turning it off :stuck_out_tongue: and would inevitably get angry when someone else used it and left it on high to blind me by surprise :neutral_face: .

I also agree that headlamp buttons should be on top or bottom, as I tend to grab the body with my thumb (underneath) and forefinger (on top) to use the switch. A button on the end works well when hand-holding, but not while on the head strap.

Again, I would develop a strange habit to resolve this; I would grab the lamp sideways with (right-hand) thumb on the tail and middle finger on the head in order to use the button without moving the light. You could do the reverse with the thumb on the button, but for me this would put my hand in front of the lens and partly blind me.

Too bad about the Moon issue, as the kit is very nice. Including the short tube is a great idea that satisfies more buyers. I don’t mind the “hidden” Turbo as that’s how most of my lights work. Hiding Turbo gives a pseudo-muggle mode for casual users and gives fast access to the highest output.

Take note, Sofirn. Users want reliable, quick access to both the lowest and highest outputs.

Sofirn has asked for my feedback, so I feel like there is room for some change. We’ll see!

Thanks for the review gchart :wink:
It seems to be a nice headlamp :wink:

I’ll make “mine” these words, too:

I hope Sofirn “listens” to these things and that you can pass them our thoughts!
Being a 18650/18350 headlamp, I would get one if the Moon/direct access to moon is included :wink:

I’ve asked for Low to be lower, 1-3 lumens. And for direct access via long-press from Off.

I’m sure this is harder to change, but I also mentioned to them that the end-button is more awkward to use than side-button.

I think the headlamp is great as-is, but these things could make it a huge hit.

Thank you :wink:
And I have the same opinion, this may be a big hit budget headlamp :wink:

Thanks gchart. Those would be great improvements. Although I’d also like to keep the 12 lm low mode in addition to the 1-3 lumens (or even lower) ultra low/moonlight mode. I think that would be ideal.

The steel clip IMHO appears to be an improvement over some others provided by other mfg’s.

May end up getting the light to add to my right-angle tube light collection (for the time being, EagleEye X1R). Definitely could use a moonlight low mode.

+1. However, if they can reduce Low to 3lm or so, that would be acceptable. The spec is 5lm, but gchart measures 12lm, so it definitely needs to come down.

The button position can’t really be changed and that’s okay for this iteration as Sofirn tends to go to “v2” within a few months :stuck_out_tongue: .

MicroUSB is a terrible connector, but unavoidable at this price. I won’t use it, anyway. Surprisingly, I do sometimes use the USB-C charging on my Astrolux FT03, mainly because it’s faster than my “real” charger. I think built-in charging is great for muggles that can get everything they need in one kit, but I’d gladly trade it for a better UI or an extra strap (they wear out quickly, though I’m still using some 16 years old).

Thanks goodness there’s no SOS :+1: , especially one in the main sequence! There’s a special place in hell for companies that put any bright flashing mode there.

The AliExpress page adds Sofirn’s “3000mAh” 18650 to the kit for $3 more. Nooner found the cell to be a DLG that 59 reported to be similar to the LG MH1. That’s not a high-drain cell, but $3 is fair enough. Note that Sofirn’s protected “3400mAh” cell was found to be the exact same battery.

Too bad we can’t have Narsil or Anduril on everything :wink: . Budget drivers likely don’t use ATtinys, but a man can dream.

I need a new headlamp and would love to buy a Sofirn, so… firmware improvement would be nice and a group buy would be awesome.


# Lowest level < 5lm

# Hold from Off —> Moon/Low

If #2 is unreasonable, what about disabling mode memory and always starting at Moon/Low? 3-mode lights don’t really need memory and turbo is always available.

If the button is easy enough to press, you might be able to grab the sides of the head with thumb (under) and middle finger (top) and use the forefinger to press the button. Maybe. I can see how the button works best on the end from a design and manufacturing point of view, since there’s likely room for it to be recessed and the overall appearance is cleaner. It also gives access down the axis of the tube, which might be useful during assembly?

Meanwhile I have also received my SP40. It's nice of Sofirn to include the 18350 battery tube. However, I also asked Sofirn to forward some suggestions to improve the UI, e.g. a hidden moonlight mode (long press from OFF) as well as a better configuration for the indicator LED. As far as I was told, they will forward my feedback to Barry.

nice shorty light.

if it have moon mode around 1 lumens + ramping UI then im all over it :slight_smile:

too high, it should be 0.3-1.0lm certainly not more then 1lm.