Review/Impressions of the Sofirn SP35 (late 2020 model)

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Review/Impressions of the Sofirn SP35 (late 2020 model)

Long live the regulated light.


A new release late in the year, the 2020 model Sofirn SP35 has had a bit of a rocky introduction, with very early examples shipped with a reflector that resulted in a janky beam pattern, and the entire first production run lacking any thermal regulation or step downs, attributed to software bugs in the driver.

While there is no easy way to discern units fitted with the original flawed reflector without having them in hand, the units that lack temperature regulation have been designated "no stepdown" or "no-ATR" in their item listings.

At this point in time, the distribution channels should be clear of units with the flawed reflector, and stock of the "no stepdown" units has mostly been exhausted, except for what remains available through Amazon in the U.S.

These impressions are based on a unit with the revised production reflector, and no-ATR.

The Company

Sofirn has earned a reputation as a manufacturer of high-quality budget flashlights, and collaborations with the flashlight community to produce well-received projects like the BLF LT1 lantern, and special editions of their other lights.

While the current packaging carries an updated black and orange motif, investments are concentrated on the product, and not the packaging, as before.

Unfortunately, something else that has continued is the company's penchant for confusing model names, in this case by recycling the SP35 moniker that was previously applied to a multi-cell can light in 2017.  This new incarnation of the SP35 belongs to a different class, and one can only guess as to why it wasn't given its own unique model designation, or even an amended appellation to mitigate any potential confusion.

The Light

More fittingly than the 2017 model, in physical terms, the 2020 SP35 continues the lineage of the SP-series single-cell tube lights, but adopts two modern developments, in the form of 21700 cells, and on-board charging via a USB-C connector.  Its dimensions are given as 126mm x 28mm, and with the bundled 5000mAh cell, it weighs in at 147g.

But somewhat disappointingly, unlike the SP32A, the SP35 is only available in the customary black color, at least for the time being.  As a "tool" light, and not a showpiece, other muted shades would be fitting, and welcome.

Joined by a couple siblings, a cousin, and others.

My sample contains no flaws in the anodized finish, but does have a dust fiber adhered to the inside surface of the lens, but it does not affect the beam.  The SST-40 emitter is well-centered relative to the smooth reflector.  Though the specs indicate a purple AR-coated lens, I am uncertain as to whether it is actually present.

While the tail cap contact is made via dual-springs, the head/driver contact is an unsprung pad, directly on the PCB.

Although the tail cap is configured in a saddle shape often associated with tail-switched designs, the SP35 is solely controlled by the electronic switch on the body.  A physical tail switch is planned for a future iteration, the SP35T.

The shape of the tail cap is not conducive to tail-standing, and I would not expect to use it in that fashion.  In the absence of a tail switch, I would have preferred a fully-enclosed cap that would better permit such usage.

As is customary for Sofirn lights, glue is used during manufacturing to discourage disassembly.  The bezel is secured with glue, and on my example, the body tube appears to be as well, resisting moderate force to unscrew it from the head.


The light comes packaged with a dual-direction clip, a pair of spare O-rings, a lanyard, folded instruction sheet, and a USB-A to USB-C charging cable.

The SP35 can be purchased as a kit bundled with a 4000mAh or 5000mAh rechargeable 21700 battery, reportedly a Lishen LR2170SA or SD cell, respectively.  While it is more than adequate for the modest demands of the SP35 (said to draw a maximum of ~5 amps), it is not a high-discharge cell (1, 2) particularly suited for more demanding direct-drive lights.

With the body lacking any oversized features, and dimensions similar to most single-cell tube lights, it should not be difficult to source one of the generic compact holsters sold under various labels (Jaxman/Jetbeam/Skyben/Astrolux/XTAR) to suit the light.  I've found that such a holster, which fits 18650 lights like the SP32A well, is doable, but a bit tight for the SP35.  I would suggest the next step up, but given the nebulous descriptions in most holster sales descriptions, careful consideration is warranted.

User Experience

The SP35 is controlled by a single electronic switch on the body.  Compared to the SP32A, the button is larger and lacks a bezel, which perhaps makes it easier to find by feel, but more susceptible to "stiction" if pressed off-center.  This characteristic might be one area where the "budget" nature of these lights manifest themselves, though it is only a minor quibble that would probably go unnoticed by most.

A simple click turns the light on or off, and holding the switch advances through the various output levels in the default stepped mode group -- Eco (7lm) / Low (120lm) / Medium (400lm) / High (950lm) -- with the last-used setting retained in memory.

The “special” modes are hidden behind double-clicks -- Turbo (2000lm) -- or triple-clicks -- Strobe (2000lm).  While in Strobe mode, a double-click alternates between Strobe and SOS/Beacon mode.

An extra-low "Moonlight" mode is accessed by pressing and holding the switch while the light is off.  This is incorrectly documented as Eco mode in the instructions, and is of lower intensity than Eco.

That same moonlight mode can also be activated momentarily by clicking, and sustained by holding, the switch when the light is electronically locked-out (four clicks from off).  A momentary click in this state results in a bright double flash to serve as an indication that the light is locked out.

In the alternate ramping mode, the SP35 requires approximately ~3.5 seconds to fully ramp up, ~4.5 seconds to fully ramp down, worse than the SP32Av2.  When ramping up, the climb is initially very rapid, before adopting a more gradual rate before ending with a blink at the high limit.  When ramping down, the descent rate is more consistently and fully gradual, but does not end with a blink at the low limit.  While it is a nice feature to have present, I would not consider it a strong suit, or preferable to the stepped mode.

Overall I find the UI and mode spacing to be generally well-executed, and practically identical to another well-rounded EDC light in my experience, the Olight S30RII.  With the SP35, Sofirn has fulfilled my previous wish that the SP32A emulate the Olight's UI behavior.


Charging can be accomplished via both USB-A and, more notably, USB-C (hallelujah!) power sources.  The latter has not been properly implemented in many budget lights that have adopted USB-C ports, so it is a welcome feature.  My measurements indicated a ~1.6 amp draw while charging, and a full charge measuring 4.19 volts with the bundled 5000mAh cell, which originally arrived at 3.49 volts.

A power indicator embedded in the switch flashes red while charging is in progress, and solid green when complete, as well as signaling charge status for five seconds each time the light is switched on (green = >30%; red = <30%, flashing = Achtung!).  In addition to the warning indication, the light will step down, and shut off to protect against low voltage.

The USB-C port in the head is protected by a rubber cover shared with other Sofirn-produced lights, so spares are not bespoke and should be easier to obtain.  The connector in my example (not pictured) is not perfectly centered in the portal, but that does not affect its function.  However, with the increasing displacement of micro-USB ports in favor of the relatively wider USB-C ports, one potential issue to be aware of is that cables with larger connector housings may not fit into the small, constricted recesses in some lights.  The bundled cable does not present that problem, of course, but some third party cables may.


Empirical testing by others (outside my province) on the no-ATR version has shown the SP35 to be a consistent performer, though the output levels do fall shy of its claims.  But, perhaps more importantly, it can sustain those levels for prolonged periods, and on the no-ATR version, even on the highest output modes, albeit with some risk to the safety of the uninitiated (aka "Muggle") user.

"Turbo" modes make for great sales copy, but understandably, are burst modes that can only be sustained for short periods.  However, when lights are overpowered, or overdriven (and oversold), that can affect the normal lower modes as well, and cause performance to suffer, which is a dirty little secret that isn't talked about in the ad copy.

While it remains to be seen how the yet-to-be-released ATR-enabled version of the SP35 will perform, the results from the no-ATR version suggest it has enough thermal capacity to also perform well, and sustainably, as long as the driver programming isn't overly conservative.

The Luminus SST-40 emitter employed by the SP35 is of unspecified nature, but is said to be 6000-6500k.

I would characterize the color temperature to be at the low end of that range, comparable to the 5700k XHP50.2 in my Astrolux EC01, and without the noticeable blue cast that the 6500k SST-20 in my SC31B exhibits.

The beam pattern hews closer to the thrower end of the scale, with a smaller, well-defined hotspot, but with more than sufficient spill for all-around usage, and much better suited to such duty than the SC31B.

In contrast to the EC01, the corona around the hotspot is mild, and has little to none of the (ugly green) tint shift that the XHP50.2 in that light, and other Cree "2" series emitters exhibit.

Compared to the SP32Av2, which has a well-defined ring surrounding the hot spot, the only ringing present with the SP35 is surrounding the outer limits of the overall beam.

PWM was not observed in a cursory attempt to detect its use.

Overall, I'm pleasantly surprised, and quite pleased by the beam, which lacks the glaring faults of the others cited.  It would be even better if given an OP reflector to further its smoothness, where it already betters the others.


Beam Shots


The beam shots below are provided mostly for comparison purposes, and while they do give a generally accurate depiction, some of the nuances in the beams aren't captured by the camera.

SP35 Medium mode

Sofirn SP32A v2.0

SP35 (left) vs SP32A (right)

Astrolux EC01

SP35 (left) vs EC01 (right)


While direct-drive lights with highly-configurable UIs have been the trend, and fashionably popular with light fanatics, I'm glad that the workmanlike SP35 "bucks" that trend, with a simple, easy-to-master interface, and consistent performance from its constant-current driver that does not suffer as battery voltage decreases.

Despite some birthing pains, the SP35 is a light that carries its family lineage well, with greater capacity and convenience brought by the 21700 form factor and on-board charging.  My objective was to obtain a more modern evolution of the SP32A, and that was readily fulfilled.

It may lack the flash and sizzle of the much talked about lights that can boast higher outputs (at least temporarily), endless configurability (but only after one learns the morse code), or novel(ty) form factors, but there is still something to be said for solid, not showy, tool lights, and a place for both.


Sofirn Official Online Store

Sofirn Official Store Aliexpress

Amazon US (no-ATR version, as of 05-Mar-2021)


Addendum (Aug-2021) - Accessories

Since the original review, Sofirn has added a couple accessories suitable for the SP35 to its stores:

  • A magnetic tail cap
  • A carrying holster ("small" size)

The magnetic tail cap adds some utility to the SP35, while addressing one of the common complaints -- the shape of the original tail cap -- and still retains provisions to secure a lanyard.


Sofirn's "small"-sized holster is a good fit for the SP35; in fact, it's better suited to a 21700 light than the 18650 lights on Sofirn's stated fit list.  It has sufficient length and diameter to comfortably accommodate the SP35, or other 21700 lights, and avoid the tight fit and stretching needed to squeeze it into a holster meant for an 18650 light.


However, given the protruding power button, it is still prudent to lock out the SP35, to avoid unintentionally turning the light on while carrying.


Various other attempts to procure a holster resulted in examples either too large, or too small for the SP35, despite careful research to match it dimensions to product descriptions that ultimately turned out to be wrong.  Hopefully, Sofirn will continue to stock this holster, or at least notify shoppers if it changes specs or suppliers.





Addendum 2 (Sep-2021) - Diffuser


Another accessory nicely suited to the SP35 is the Lumintop's Size L diffuser, made of a glow-in-the-dark material.

Edited by: TheIntruder on 09/09/2021 - 02:23
zoulas's picture
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My next light.

longuylander's picture
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I just got the email from Sofirn that my SP35 with ATR has shipped.

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zoulas wrote:
My next light.
longuylander wrote:
I just got the email from Sofirn that my SP35 with ATR has shipped.

It will be interesting to see how well the ATR version performs.

Hopefully, for those mulling the SP35, there will be public results soon enough to allow a choice while the non-ATR version is still available on Amazon.

Either way, it’s still nice to have a light that is regulated and won’t sag. Last time I pulled out and used my EC01, it seemed a bit off, and a voltage check confirmed that the battery was run down.

Last seen: 1 day 1 hour ago
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Just received this light today. Only 2 weeks which was fast in these times.
Light arrived in perfect condition with the additional magnetic cap and holster.

I’m no light fanatic and really only want a couple but have already found myself ordering another 4 Sofirn SC11C’s. Will be great as gifts or for other family members.

This is my second light, with the first being a bigger thrower FT03.

I’ve got to say really impressed with the quality and functionality of this light. The ramping is a bit quick but bought it for the basic stepped settings.
Using outside tonight and blown away at how much flood and throw this has for such a small light. For me, I don’t have external chargers, so the USBC is a key function.
Love how the clip, it attaches to a cap and easily slips into your pocket.
This is going to be so handy as a general torch around the house and going out to the shed,

Next light’s are going to be a spotty to use on my .22cal for rabbiting/foxing….probably the Convoy C8+ KW CULPM1.TG and dedicated green Convoy C8+ with KP CSLNM1.F1 green light
Notice my 3rd line!!!!! and already I’m looking at owning 4/5 with others to give away. Smile

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It’s a great light, shame about the thermal regulation though, it still needs a lot of work. Once it hits 50°C the roller coaster begins.

The switch died on my review unit Sad

Texas Ace Lumen Tube calibrated with maukka lights

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wle's picture
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if it has a side switch, i would prefer the light be 12mm shorter, rather than the awkward saddle shaped tail end

that only makes it longer for no reason, in fact it is harder to tail=stand [which i do all the time] than with a plain flat end.
it seems like they can;t be doing this on purpose = maybe they had some old tail caps lying around w this weird shape\
or didn;t want to design and make a decent one

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Funtastic's picture
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Buy the magnet tail cap that’s now available

Texas Ace Lumen Tube calibrated with maukka lights

New Zealand store – (NZ customers only)

YouTube channel – (Demos for my customers, and reviews)

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Funtastic wrote:
It’s a great light, shame about the thermal regulation though, it still needs a lot of work. Once it hits 50°C the roller coaster begins.

The switch died on my review unit Sad

I’ve found the SP35’s switch to be its biggest weakness. Compared to the Sofirn’s silicone switches, and its metal button switches with the bezel, the action isn’t as good, and I’ve experienced more mis-clicks with it than the other two types combined. It’s not something I’d want to use with something like Anduril. And to hear it may fail? Ugh.

But I guess it does give the SP35 greater physical resemblance to its clear inspiration, the PD36R.