[Review] Sofirn SP40 headlamp

Hello everyone,

I would like to tell you about my impressions of Sofirn's first self-developed headlamp, the SP40 which comes with an integrated charging port.

As usual my impressions are subjective but unbiased and honest. Apart from the light itself I did not receive any kind of compensation for posting this review here.

Sofirn's SP40 can be purchased from several sources such as Amazon and AliExpress.

Amazon DE

Amazon US


AliExpress CN

Some specs i.a.w. the manual:

Length: 108mm (with 18650 tube)
Head diameter: 25mm
Weight: 63g (without battery, with 18650 tube)
Battery size: 18650 or 18350 (with short tube)
Max. output: 1.200lm / 4.620cd
Runtimes: 1h 50min (Turbo), 220h (Low)
Emitter: XP-L HD 5.000K on 16mm MCPCB
Driver: 3V, probably FET with current-limiting resistors
Reflector: Orange Peel
Regulation: thermal via ATR (when reaching 55°C on driver)
Water resistance: IPX7 (1m up to 30min)
Mode memory: Yes

You can find the manual both in English and German on my sharepoint: ► click here ◄.


The content is quite generous:

  • Sofirn SP40 headlamp
  • head strap
  • additional 18350 battery tube
  • clip
  • 18650 Li-Ion button top battery with 3.000mAh
  • microUSB cable
  • 2 spare o-rings
  • manual in German and English language

Again the not too sturdy cardboard box came to my attention. It suffered quite some damage on it's way from China to Germany. A sturdier box like the ones Simon Mao uses for his Convoy lights would be nice. However, nothing inside the cardboard box was damaged.

A closer look onto the parts...

Looking into the "eye" of the light you will find Cree's XP-L HD with dome incorporated into an orange peel reflector. The LED is not properly centered. The spring has no bypass or is supported by a double-spring type but that's okay in terms of the moderate power consumption and its rather simple driver design. Anyway, in terms of better efficiency it would have been a nice option. I could not find any retaining ring, thus I presume the driver is kept in its position with glue or press-fitted.

On the upper side of the flashlight's head you find the e-switch. During operation this switch is permanently illuminated. I would have preferred the switch to be on the side of the head instead on top of it, see Armytek Wizard Pro for comparison. On the backside you find the microUSB charging port, protected by a rubber boot. A rubber boot is always something people can argue about when it comes to charging mechanism. Personally, I prefer magnetic (proprietary) charging or USB ports that are hidden and protected from any ingress inside the threads (see D25 for comparison). There is no AR coating on the glas lens. Sofirn does not use glue, so the bezel ring can be removed easily to get to the inner parts of the lights, e.g. to change the reflector or install a TIR optic.

The SP40 comes with the 18650 tube attached. Additionally, Sofirn supplies a short 18350 tube to use it with smaller batteries. That's a very nice move. Both tubes came in high manufacturing quality, properly deburred, well-anodized and slightly lubricated - well done! The short tube also fits to other Sofirn lights such as SC31, SP31 V2.0, SP32A V2.0. The tailcap's spring is also kept simple. The tailcap's thickness is very thin, probably due to low weight requirements for the entire headlamp. Unfortunately, Sofirn did not integrate a magnet into the SP40. The knurling is very grippy which is good for (un)screwing the cap.

The head strap

The head strap is made of durable material and shows the Sofirn brand on several spots. The headlamp mount is made of simple black rubber. This could actually be a problem once you start to sweat on your forehead. Unfortunately, the overhead strap cannot be removed, at least reversibly removed. If you want to wear your headlamp around your neck (as I prefer) you will need to cut the overhead strap off or use another head strap with a removable overhead part, e.g. Armytek or Olight head strap.

The greatest downside of the head strip is the mount. It's a real PITA to get the SP40 squeezed through those rubber-made rings. You will probably think twice before you detach or attach the SP40 from/to the mount. The flashlight sits very tight, so tight that turning it to adjust the beam direction will often lead to unintentional lockout of the tailcap or head unit. :-(

User Interface

The switch controls all flashlight functions as follows:

  • Short click to turn on, another click to turn off.
  • While the light is on, hold the switch to cycle through modes: Low (5lm) → Medium (90lm) → High (450lm)
  • Doubleclick to activate Turbo mode (1,200lm), one click to return to last mode.

Basically, this UI is quite easy and intuitive but the SP40 lacks a real moonlight (≤ 1lm). 5lm (which appear to be around actual 12lm) on Low is way too much for a headlight. Furthermore, holding the switch pressed down to cycle through modes or using a doubleclick to enable turbo mode is not very comfortable with the switch's position on the top side of the head. I don't like the indicator LED being enabled permanently during operation. It's somehow distracting and serves no purpose. It would be much better if the indicator light is on when on standby or - even better - by user defined setting.

On the positive side the SP40 has thermal regulation that reduces power consumption and brightness to approx. 500lm once the driver's temperature reaches 55°C. Unlike Convoy's H1 it cannot overheat. Unfortunately, the flashlight misses a better, more stable current regulation. As the voltage drops the brightness will drop accordingly. A fully regulated buck driver like Sofirn's SP32A V2.0 would be a nice improvement.

Beam profile

As mentioned before the XP-L HD in my sample is slightly off-center. Fortunately, this has only few impact on the beam quality as the orange peel reflector and the primary optic of the XP-L HD dome have a softening effect. The SP40 uses PWM on lower modes as can be seen below.

The beam profile is not too floody but has a distinct hotspot surrounded by a spill. Unlike many floody headlamps the SP40 provides a good compromise between light in front of your feet and some light ahead of you. There's just a slight tintshift around the hotspot and the spill with some yellow corona but this is more or less nitpicking. I really like its CCT which I measured around 5,100K, i.e. a very neutralwhite colour temperature.

Size comparison

from left to right: C01S, SP40 (long tube), SP32A V2.0, SP31 V2.0, SC31

As mentioned before the short 18350 tube fits perfectly onto other Sofirn lights such as SP32A V2.0...


Sofirn was quite successful with launching their first headlamp. However, it lacks some things that could be improved to make it even more successful. For the price you pay you get a lot. The light is well designed and manufactured, omitting the off-centered LED which is a common problem with many manufacturers. Those things I would like to see improved will mostly be "under the hood" and should be feasible with manageable efforts, such as...

  • head strap with detachable overhead strap and half-open plastic mount (see Armytek)
  • magnet in the tailcap
  • a real "moonlight" mode with 1lm or less
  • deactivatable indicator LED (see Q8/SP36)
  • linear or buck driver design with ATtiny85 MCU (Andúril/NarsilM)....cost increase by approx. $ 1-2
  • exchange XP-L HD 5.000K 70CRI by SST-20 5.000K 70CRI....cost reduction by at least $ 1-2
  • offer more LED options (SST-20 4.000K 95CRI, LH351D 5.000K 90CRI, Luxeon V2, ...)

Thanks for reading and for your feedback!



Thanks for this review! I just received mine so it's charging in preparation for the night!

I think I'm going to get a lot of use out of the 18350 tube when used as a head light. Otherwise, it will be great forward attached to a backpack strap with the 18650 tube when hiking. I need to see if it can be clipped upside down so the switch light won't bug me.

I'd say the biggest drawback has to be the headstrap. The silicone rubber(?) rings and the flashlight body are far too grippy (ESPECIALLY with the 18350 tube installed), it's very hard to adjust the angle with one hand, sometimes two. I've unintentionally unscrewed the head/body/tailcap many times trying to adjust it. In comparison to the ease in which I can do so with my ZL H53Fc it's a frustration. That being said, I really like it and find it to be a great value ($25 sale Amazon Prime).

Yeah, honestly the headband seems more suited for an AA/14500 light - for which it worked really well, when I tried it out. So…there’s that at least, I suppose?

I received mine today.

First impression is that I don’t like the UI. I may gift this to my Wife who likes lights with built in chargers.

I much prefer the UI of either their SP32V2.0 or D25S.

I’d also appreciate a magnet on the tail cap.

Nice tint. Good beam pattern, I’d probably diffuse it, if I do keep it.