Sofirn SD06 Diving Flashlight Review
The Sofirn SD06 diving flashlight has a cool white Luminus SFT-70 LED and a smooth, deep reflector. The rotary/press switch is a show stopper – great for diving!
Official Specs and Features
Here’s a link to the Sofirn SD06 diving flashlight product page.
Versions
Sofirn appears to make just one version of the SD06 diving flashlight.
Price
With a 21700 (the one seen in this post), the Sofirn SD06 diving flashlight comes in at a reasonable $37.99. Or around $34 if you have your own 21700 and don’t need theirs!
What’s Included
- Sofirn SD06 diving flashlight
- Sofirn 5000mAh 21700
- Charger
- Charge cable
- Spare O-rings
- Lanyard
Package and Manual
I did not get a manual! Sofirn’s website describes the light pretty thoroughly though. If they send a PDF, I will add it here.
Build Quality and Disassembly
I am not a diving flashlight expert, I will evaluate this from the flashlight side of things.
The build quality is fine. The light is $34, so I am not sure what you might expect, but Sofirn is definitely punching above that price point!
Only the head comes off. The threads are long and well-lubed. The anodization means the light can be mechanically locked out, too (and probably still maintain water tightness.)
Both the head and tail have a spring.
I wasn’t able to remove the bezel. And despite the tailcap appearing to be a separate piece, I was also unable to remove it.
Size and Comps
Size: 36 mm ( head diameter) *1 34 mm (length)
Weight: 126 g(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 SD06 diving flashlight is “primarily” (or “only” I guess, depending on what you make of flashlight needs) a diving flashlight. As such, you wouldn’t expect a pocket clip (and there is not one).
There is a lanyard though, and a very secure place to attach it.
The lanyard is “more than basic.” It has a wrist strap as well as a metal loop (more than a split ring!).
Power and Runtime
The Sofirn SD06 diving flashlight runs one 21700 lithium-ion cell. If you get the package, you’ll get the cell seen below – a 5000mAh flat top 21700.
That cell goes into the Sofirn SD06 diving flashlight in the usual way – positive end toward the head.
Below are runtime tests for every mode. Really to replicate real-world usage, I guess these should have been done underwater. Forgive me, for I am not set up that way. I hope you can interpret these and they’ll be useful for your usage! (I find this to be a reasonable non-dive light, too!)
Output doesn’t meet the claimed 3200 lumens and steps down dramatically. After the stepdown, you’ll get around 800 lumens for nearly 3 hours.
The light does exhibit low voltage protection but also steps down along the way. It even starts blinking, and will do so for 30+ minutes, so you should have ample warning before the light shuts off.
Charging
The Sofirn SD06 diving flashlight does not have onboard charging but it does include this single-bay charger. This charger is powered by USB-C.
I did not do any testing with this charger. I have other Sofirn reviews where this charger was tested.
Modes and Currents
| Mode | Mode Claimed Output (lm) | Claimed Runtime | Measured Lumens | Tailcap Amps |
|---|---|---|---|---|
| High | 3200 | 2.33 | 2378 (0s) 2109 (30s) |
(Couldn’t read) |
| Medium | 1100 | 4h | 801 (0s) 798 (30s) |
1.95 |
| Low | 300 | 12h | 209 | 0.35 |
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 user interface for this Sofirn SD06 diving flashlight is quite interesting. I have a feeling it’s dive-specific but it’s still useful for us non-divey people.
On the head, there’s a very proud rotary switch that can also be pressed.
Action on this switch is very deep! There’s probably 5mm of travel to the switch.
Importantly, the switch also rotates. It can be locked or unlocked. Notably, it can be locked while on, too!
Here’s a user interface table! The switch is not at all clicky. It’s very smooth and has a very nice bit of firm resistance all the way down.
| State | Action | Result |
|---|---|---|
| Rotary unlocked – Off | Fully depress | On (Mode memory) |
| Rotary unlocked – On | Fully depress | Mode advance (LMH) |
| Rotary unlocked – On | Hold | Off |
| Rotary locked – Any | Any press | No change |
LED and Beam
Sofirn has used a Luminus SFT-70 in the SD06 diving flashlight. This is a 6500K version, so it’s quite cool white. The emitter is paired with a very smooth, fairly large reflector.
LED Color Report (CRI and CCT)
These measurements confirm the cool white nature of this emitter. It ranges from around the claim all the way up to 7400K. CRI is low, too.
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
The Sofirn SD06 diving flashlight is a neat light, whether for diving or for the unusual rotary/deep press (lockable) switch. I enjoy the switch, in fact! The output here is good and the emitter/reflector combination provides a reasonable throw. Pricing this at $34 makes it a very good backup light for diving (etc!) if nothing else!
The Big Table
| Sofirn SD06 diving flashlight | |
|---|---|
| Emitter: | Luminus SFT70 |
| Price in USD at publication time: | $34.00 |
| Cell: | 1×21700 |
| Runtime Graphs | |
| LVP? | Yes |
| Switch Type: | E-Switch |
| Quiescent Current (mA): | ? |
| On-Board Charging? | No (1-bay charger included) |
| Claimed Lumens (lm) | 3400 |
| Measured Lumens (at 30s) | 2109 (62% of claim)^ |
| Candela per Lumen | 25.81 |
| Claimed Throw (m) | 375 |
| Candela (Calculated) in cd (at 30s) | 1754lux @ 5.825m = 59514cd |
| Throw (Calculated) (m) | 487.9 (130.1% of claim)^ |
| Claimed CCT | 6000-6500 |
| Measured CCT Range (K) | 6300-7400 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
- Very simple user interface
- Great throw
- Low cost
- Can be locked while on
- Build quality seems robust
What I don’t like
- Very cool white
- Low CRI
- Low is not too low – around 200-300 lumens (probably fine for diving?)
Notes
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