Sofirn wrote to me some time ago and asked if I would like to do a review of a new lamp. I hadn’t reviewed a lamp for a while and was interested in doing so.
This lamp was sent to me free of charge by Sofirn. I had no influence or other obligations apart from writing a review. Thanks to Sofirn for this!
About the SD06 is almost nothing known yet. It is a compact dive light with a single SFT-70 LED, a classic SMO reflector and a magnetically operated switch with integrated simple lockout.
Accessories
The lamp was sent to me in a simple brown box. It is marked with a sticker for the LED type and other information.
It contained a lanyard and spare O-rings, a charger with USB-C cable, in which the supplied battery “just fits” - no wonder, according to the imprint on the back, this charger is not suitable for 21700 batteries, but only for 18650 or smaller. According to it’s label has 0.75 A charging current.
There was no manual inside the box, since it was a pre-release prototype. For mass-production there will be a manual included.
Appearance, quality and feel
The SD06 is kept very simple in overall design. The rather solid head has large cooling fins and the battery tube has individual recesses to ensure a better grip. This means that the lamp lies securely in the hand even when wet.
The wall thickness of the battery tube could be a little thicker. The curbs in the tube make it appear less solid.
The design is reminiscent of older Fenix lamps (especially the Fenix PD40 1st gen), especially on the lamp head, and looks great in my opinion. Simple and functional.
Tailstand is not possible as there is a large hole for a lanyard on the back.
The most striking feature is the protruding switch. Unlike most other lamps, this works magnetically: a Hall sensor is actuated by a magnet in the switch, which means that there are no holes in the housing and tightness is ensured. The high button enables another feature: the lamp can be put into lockout mode by turning it. This can also be done with one hand and works both when switched off and on, at any light level, and is a good idea to offer a simple lockout without multiple clicks or similar.
The protruding switch makes it easy to operate even when wearing thick gloves. The only disadvantage for some users could be the lack of a pressure point due to the magnetic actuation; as with some keyboard switches, the button can be pressed as far as it will go without there being a noticeable click.
The most important feature of a diving lamp is its water resistance. The lamp withstood all tests under water jets and submersion at depths of up to 1 m without any problems. Since I’m not a diver, I don’t have any other testing options available to me; however, like an Armytek Dobermann, it has two O-rings on the bezel and battery tube, which should ensure a diving depth of at least 50 meters.
Although the O-rings have been greased, the thread should be regreased before a dive.
Unfortunately, the front glass fogs up from the inside after use in very cold water. This disappears again after a while, but can change the beam depending on the intensity.
The SD06 is not easy to disassemble. The bezel and driver is glued.
UI
Three light levels are available. The SD06 is easy to operate:
- Short click of OFF: Start in the last light level (mode memory)
- Long click of OFF: No reaction
- Short click on ON: Switch through the light levels
- Long click on ON: Switch off lamp
- Turning the button to the right: Lockout (also possible when the lamp is switched on)
- Turn the button to the left: Cancel lockout
There are no flashing modes and no hidden menus. There is mode memory in all light levels, i.e. the last light level used is saved and called up when the light is switched on again.
However, I would have two suggestions for improvement here:
A proper low mode (3-5 lm) should definitely be provided, which can be accessed via the unassigned “Long press OFF” function. This ensures that such a mode is not in the normal switching sequence what can be useful while diving, but can be reached safely and without previous glare by briefly switching off and then pressing and holding. This can be helpful if you need light at close range after a dive on a less well-lit deck, because at the current lowest level, the lamp is far too bright at close range due to its rather concentrated light beam.
In addition, the current lowest light level of 260 lm should be reduced to around 170-200 lm to ensure a greater difference to the higher light level, especially when the battery is half empty.
With this adjustment, the lamp would also be suitable for everyday use outside of diving.
Batteries
A 21700 with Sofirn branding is supplied. It is specified with 5000 mAh. The discharge test with a Vapcell S4 v2 at 1 A shows 4975 mAh as result, which is good.
Other unprotected 21700s and very short protected ones will fit, but a Fenix ARB-L21-5000 (76 mm incl. buttontop) is too long. There are springs on both sides, which give a certain amount of leeway in length and effectively prevent the power supply from being interrupted in the event of an impact. A 21700 should not be longer than 74 mm; some protected 21700s could still fit.
If necessary, 18650s can also be used without an adapter: simply insert, screw shut and you’re done. The capacity is lower and the runtime will therefore be significantly shorter, and the output may also be lower.
LED
A cool white Luminus SFT-70 LED with 70 CRI is used. This 6 V class LED does not have a dome and normally provides a good beam, even when using smooth (SMO) reflectors. The SD06 is equipped with just that.
The tint is slightly green in the low power range, but pleasantly white at higher light levels, changing to a clearly visible blue at the highest level. The green tint at low operating current is a known problem with Luminus LEDs and can only be avoided by using LEDs with a certain color binning (as far as possible); see also my review of the Luminus SFT-70.
A neutral white LED (5000-5500 K) with a slightly negative duv would also make the SD06 suitable for underwater photography, at least with a suitable diffuser.
The front glass has an apparently high material thickness (2-3 mm), but is not AR coated.
Running times
Running time test in cold water (immersion conditions)
Used luxmeter: Benetech GM1020 in data-logging mode
It is clear that the focus here was on long runtimes, something that is essential when diving, as it is impossible to change the battery under water and the energy budget therefore plays an extremely important role.
When starting at the highest level, it regulates back to the lowest level relatively quickly. This does not happen smoothly, but suddenly. It is then still possible to switch up to the highest level without any significant loss of power. The highest level should therefore be seen as a kind of “turbo” for very limited periods of use. The step-down is presumably always time-controlled.
From a certain battery voltage (3.6-3.8 V), the highest level only delivers around 1600 lm. Only when the battery voltage continues to drop can the highest level no longer be activated at some point.
The middle level is fully regulated. After around 45 minutes, the luminous flux decreases in a controlled manner and then remains at a level around 30 % lower for a further 60 minutes. After that it steps down again.
When the battery is low, the lamp flashes at regular intervals and further reduces the luminous flux. This is seen in the chart after around 180 minutes, which is indicated by these dips. At this point at the latest, you should either abort the dive or use a spare (backup) lamp. At some point the lamp switches off, but can still be switched on at the lowest level before this option also fails at some point. The battery has 2.7 V at this point, and light can then only be produced with the SD06 for several seconds at a time when the button is pressed.
Runtime uncooled
The behavior at Turbo does not change, there is still a hard stepdown.
At the original level, the SD06 reaches a surface temperature of around 41 degrees, which is fine. There is no risk of burns. This means that the middle stage can be operated continuously. In the runtime chart there is a slight drop due to rising temperature.
Performance
The lamp heats up quickly on the highest setting. It reduces the maximum luminous flux before the surface temperature becomes too high.
The following measured values were taken with a Samsung INR21700-40T @ 4.18 V (Charger: Vapcell S4+ 2000 mA charging current), half-full @ 3.6 V
An integrating sphere was used.
| Mode | Light flux | Brightness |
|---|---|---|
| Turbo (battery full) @ 5 sec | 3053 lm | 62400 lx |
| Turbo (battery full) @ 30 sec | 2775 lm | 56700 lx |
| Turbo (battery half-full) @ 5 sec | 1602 lm | 32600 lx |
| Mid @ 5 sec | 982 lm | 21300 lx |
| Mid @ 30 sec | 981 lm | 21300 lx |
| Low @ 5 sec | 258 lm | 5530 lx |
| Low @ 30 sec | 258 lm | 5530 lx |
Beam quality
The beam is very good. There are no color distortons in the spill or around the spot; rings are only visible on the whitewall if you look closely.
Generally speaking, the SD06 is more of a thrower; due to the relatively wide spill, it can also be used at close range in principle, although a significantly dimmer light level should be provided for this.
Due to the lack of a low level, the lamp is too bright even at the lowest level at close range.
Conclusion
The SD06 is specifically marketed for divers. However, I also see it as a simple “no nonsense” lamp for everyday use - a lamp that simply does its job. Simple operation without configuration options or flashing modes, no tactical, futuristic design, and full waterproofness makes it interesting for me as an everyday lamp. The switch, which can be operated with thick gloves and has a very simple lockout, can also offer real value.
However, I strongly suggest to add a “real” low in the 3-5 lm range for the release version, not only for everyday purposes, so that the lamp can also be used sensibly at close range, which is basically impossible in the moment. In addition, an LED with a neutral white color temperature without a greenish tint and low luminous flux should be considered so that the lamp can also be used for underwater photography (possibly with a diffuser).
Pro
- Simple design
- Battery and charger included in box
- Switch with very simple lockout
- long runtimes
- very simple operation with no flashing modes (strobe etc.)
- fully waterproof
- good beam without annoying artifacts
Contra
- lowest light level much too bright, therefore hardly or not at all usable at close range
- Greenish tint at the lowest level
- No neutral white option and/or high color rendering available
Hope this review is useful for you! 
Best regards, Dominik
