Disclaimer: Sofirn provided me with this light free of charge. This had no influence on the review
All measurements were done using hobby-grade equipment, inaccuracies and deviations are therefore possible.
Introduction
Actually I didn't want to review the light at all, but Sofirn convinced me to do it anyway. I am not a diver, so I can't say anything about its specific suitability for diving. I already found the comparatively bright lowest modes to be only marginally good for a "normal" light beforehand, whether the rest of the light can make up for this drawback, I will let myself be surprised.
Specifications by Sofirn
The SD11 is only available in one, black version. You can buy it directly from Sofirn.
Package Contents and Impressions
The light comes in the typical, white Sofirn box. On it is a picture of the light, as well as all important data. Included besides the light (with already inserted battery) are a lanyard (designed for diving), spare O-rings, a short USB-C-C cable and a manual.
My first impression of the light was somewhere between "quite a chunky light" and "fits surprisingly well in the hand". Sure, the light is neither small nor lightweight, that was to be expected given the battery size. Due to the thicker battery tube compared to 21700 lights the light really fits comfortably in the hand, the impression of weight is (on land) relatively high however.
But this also has the consequence that the light feels really high quality. In addition to that the anodization is nicely done and has a satin finish, all gaps are even and the light is flawlessly machined. The engravings are sharp and used well as an accent.
The switch is a rotary switch with an integrated button. It clicks cleanly into all positions and has a good pressure point. In the center sits an LED, which continuously indicates the battery charge level during operation.
At the front is a TIR, behind which several TN3535 LEDs are hidden. In the middle sits a red one, distributed in a circle around it are 6 more – always alternating warm white and cool white. If I see it correctly, there is an AR coated glass lens sitting in front of the TIR.
That there is no USB port on the outside of the light is probably understandable for a dive light. Sealing this would be a nightmare. All the better that the 26800 battery is equipped with an integrated charging port. This saves an additional charger and the water resistance is not affected.
Opposite the switch is a tripod thread. The contact surface is nice and flat, there is space all around, so mounting should be possible without any problems.
Nothing happens to the light and the battery if you insert the battery the wrong way around, reverse polarity protection is present. LVP is also present, whether integrated in the light or battery I cannot say with certainty – should you use the light with another battery, please verify if necessary.
Size
The light weighs 344g incl. battery. At the head it is 50.5mm in diameter, at the tailcap 34mm.without lanyard hole the light is 152mm long, with 157.5mm.
Carrying Options
Lanyard: Lanyard: The lanyard is reinforced with a plastic sleeve, long and robust. It is designed for diving, but works great overall! The eyelet is extremely robust and the lanyard is super easy to thread.
Clip: A pocket clip is not included.
Magnet: A magnet is not integrated into the light.
(Jacket)pocket: The light is comparatively thick and heavy, even if the head is not overly large. It is not suitable for pants pockets, but in a larger jacket pocket there won't be any issues.
UI
The UI is simple – The light source (cool white, warm white, red) is activated with the rotary switch. By turning the switch the light is also immediately turned on. The push button then cycles through the modes (low – medium – high – Turbo, only red without Turbo). A double click activates neutral white Turbo – that means all LEDs except red.
While diving this is certainly an advantage, because the UI is simple and fairly panic proof. In everyday life I would prefer pre selecting the light source with the switch and turning it on via the push button – but I understand that Sofirn thought of the divers for a dive light and designed the UI accordingly. After a short period of getting used to it the UI also works completely problem free for someone who is used to significantly different UIs.
Beam Profile and Measurements
All measurements were done in my 30cm integrating sphere. The temperature was between 20 and 24°C. Additionally, an Opple Light Master III and a TASi TA636B lux meter were used. Please note that this is hobby equipment, so inaccuracies and deviations are possible!
Output and Beam
The beam profile of the light is clean and largely floody. I particularly like the combination of warm and cool, I would wish that this could be activated not only in Turbo! The performance is good, but in my measurements it falls slightly short of the factory specs. First off an overview of all runtimes.
In the following picture you see all Turbos, incl. the cooled run of the neutral Turbo with all LEDs. Zoomed in on the first 10 minutes, as everything crucial can be seen there.
In the following I would like to show you the comparison between the fan cooled and uncooled light, at maximum output. The thermal regulation clearly works, so I can imagine that the specs regarding runtimes underwater are quite correct – there the cooling is significantly better. Unfortunately I did not succeed in finding a solution for a runtime graph underwater.
There is also a graph for the red mode, however without lumen figures, I can't measure those on red.
Overall it comes quite close to the specifications. The stepdowns prolong the runtime, the eye adapts to it so quickly that it doesn't bother further – and if it does, you can just bump it back up.
| mode | Output max | Output 30s | Runtime (specs) | distance (specs) |
| warm low | 240 | 240 | 11h 9min (11h) | 88m (64m) |
| warm med | 580 | 580 | 4h 35min (4,5h) | 135m (99m) |
| warm high | 970 | 970 | 2h 59min (5min + 3h) | 163m (130m) |
| warm turbo | 1760 | 1740 | 2h 30min (1min + 3min + 2,75h) | 220m (176m) |
| cool low | 360 | 360 | 11h 40min (11,2h) | 98m (71m) |
| cool med | 765 | 765 | 5h 44min (5,25h) | 128m (100m) |
| cool high | 1450 | 1450 | 3h 6min (5min + 3h) | 168m (143m) |
| cool turbo | 3030 | 2990 | 2h 18min (2min + 2,2h) | 244m (203m) |
| neutral turbo | ~3900 | ~2900 | cooled 2h 18min / uncooled 2h 24min (1min + 3min + 2,1h) | 305m (244m) |
| red (highest) | – | – | 4h 38min (4,5h) | 71m(68m) |
CCT, CRI, DUV, PWM
| Low warm | Turbo warm | Low cool | Turbo cool | Turbo neutral | |
| CCT | 2760K | 2800K | 6100K | 6650 | 4200 |
| CRI | 97 | 96 | 72 | 74 | 85 |
| DUV | 0,002 | 0,004 | 0,003 | 0,000 | -0,004 |
Detailed data on the measurements can be found here.
Flicker is in the green zone, all modes look very similar, therefore only one screenshot as an example. PWM is accordingly not visible with the naked eye nor with the camera.
Beamshots
I can't really compare the light, I have nothing similar. But I still want to show you the shape of the beam and the tints. All three Turbos, warm, neutral, cool. All camera settings identical and all pictures taken directly after another with a full battery.
Batteries and charging
The charging curve is unremarkable. The battery is charged using the typical CC-CV method, under 2.5h is quite good for a 7000mAh battery with integrated charging function, 3A corresponds to just under 0.5C, so it is also sufficiently gentle.
Summary
I'll be honest, the SD11 won't be my favorite flashlight. However, for a dive light in the hands of a nondiver, that isn't too surprising. Nevertheless, the light will still get a permanent spot – in the boat bag of my kayak. Because there, robustness and waterproofness play a paramount role. The UI is perfectly suitable for this purpose, just as it is for diving.
The SD11 is basically easy to use, you can hand it to almost anyone and there will be no problems. Anyone used to other lights, however, should be prepared for it taking a few tries until you are used to the UI
So, where to use the light? For everything where you need more than just a little bit of light. Diving, sure, but also (wet) caves, lost places or like for me on a boat. There the light can showcase its absolutely present strengths.
For the urban dog walk it was unfortunately already a bit too bright for me, on holiday "in the outback" it definitely worked well too. If ~300 lumens aren't too bright for you and you are looking for a robust, waterproof light, then I can give this light a recommendation.