Thorfire added another interesting flashlight to their product line-the S1.
Unlike the main EDC targeted lights we are used to see from Thorfire, this is a triple reflector flashlight designed mainly for long range outdoor use-any kind of outdoors activity,including scuba diving.
This is actually how the S1 is specified by the manufacturer. A scuba diving light.
Thorfire provided their S1 flashlight for test and review purpose. Read my comments in the review below to learn more about the flashlight and how it performs.
In terms of design,as we are used to see lately,there may be shares with other brands.However,I don't own similar design flashlight and have not tested such,
so I will comment the S1 as a something new to me.
Check out this 360 view in full screen mode 
https://media.megavisor.com/player/embed?3073faab-5fb6-4e43-813c-8e12539c2037#autoPlay=false
Thorfire S1 is equipped with a stable handle for more comfortable grip and to keep the hands away from the heat. It could be a main advantage when using the S1 underwater,as well.
The handle is a very useful accessory.It helps for easier carrying the relatively heavy flashlight(the control ring is still accessible with this grip).
Size comparison- Nitecore TM16, Thorfire S1, Lumintop PS03, Nitecore TM03, 18650 battery
The handle is removable(attached via big screw),so it does not force the user to keep it on in permanently. Removing it will save you some space in the backpack,for example.
The whole form and especially the body has very good design with deep grooves that ensures stable grip,plus they do not collect dust,in the same time are easy to clean.
The anodized finish is great,with very few minor imperfections. The color can be defined as grey,but has some purple hue to it,visible in bright day light.
850 gr. weight with batteries.
In my medium size hand with thin fingers.
Close up of the anodized finish.
Technical specifications from the manufacturer:
"Specifications
Material: durable aircraft Aluminum
Modes: High/Mid/Low, 3 modes
Bulb: 3x Cree XP-L LED with a lifespan of 100,000 hours
Battery: 4x 18650 3.7v batteries(Not Included)
Size: approx 155mm (Length) * 56mm(Body Diameter) * 73mm(Head Diameter)
Weight: 685-gram weight (Excluding the battery)
NOTE: The light was tightened for diving test. Please find a helper if you find it difficult to unscrew the light.
NOTE: Every flashlight passed our test under the same pressure of 100m underwater."
Thorfire S1 is equipped with three small diameter(22mm),but deep aluminum reflectors.
Perfectly centered at the bottom are three Cree X-PL LEDs,with the great surprise-they produce very pleasant Neutral White light!
The glass lenses do not feature anti-reflective coating.
I found that on my sample,all the glass lenses have a lot of particles/dust inside,which I usually do not expect,no matter the brand.
Yet they do not affect the beam,so it is not a deal breaker and may be possible to clean them after unscrewing the front stainless steel bezels(which I do not plan to do it,for now).
The overall build quality and machining are on very high level,with some little imperfections that do not affect the good impression of the work done by Thorfire
All parts are tightly screwed,without gaps(the bezels do not have a sign of the frequently seen in other brands gap,which may take a lot of dust and even could lead to water leaking.
Here,everything seems very well assembled and does not give a cause for concern.
Of course,to be absolutely sure in the flashlight,especially if it will be used for deep diving,it is a good idea to do some preliminary tests,before taking it to a serious work.
The whole body is made of thick aluminum with serious heat dissipation potential(confirmed in my runtime tests).
User Interface
Thorfire S1 has three brightness levels Off-Low-Mid-High. (in this sequence)(direct High mode activation is not possible,yet you can quickly rotate the ring without stopping on the lower modes.)
They can be activated by twisting the silver magnetic ring.
It is well designed,with width of 1.5cm and two protruding squares for good grip when twisting the ring.
The four defined positions(3 modes + Off) of the ring are placed on a long distance each other.
Every position produces soft click sound. No visual markings for the mode position.
The whole advantage of the electronically controlling magnetic ring is in the solved problem for sealing the flashlight to make it able to withstand diving at a great depth.
There is no exposed switch cap that may cause leaking under high pressure.
The switch/ring is very comfortable to use in this shape,as it does allow access from any side of the flashlight and is almost impossible to activate it accidentally.
(note that it reacts on strong portable magnets,so they should be kept away from the controlling ring,or they may activate the light)
A look at the tailcap. It has three long channels for strap/rope attaching.
Tail-standing is possible with no difficulties.
The S1 can be disassembled on three,maybe four base parts,without tools. I did not manage to unscrew the tailcap and I did not find it needed,so far.
On the picture below- head,battery tube/body,battery carrier.
Triangular cut threads.Well greased. Two insulating O-rings.
The battery carrier has reversible design-can be placed in the flashlight with any of the ends first.
It is also easy to insert the batteries,as all four sit in the same direction.
The four batteries are electrically connected in parallel. This allows you to use high drain 18650 batteries different than IMR and does not make critical the need of absolutely equal voltage of each battery.
Long protected 18650 batteries fit pretty well in the holder. It's easy to take the batteries in/out.
However,unprotected/ IMR batteries will stay very loose in their slots and may require additional components as small round magnets to keep the springs more compressed.
The positive pole of the battery carrier contacts a thick spring positioned at the head.
The negative pole,which is the whole aluminum plate(part of the construction,holding the screws on both sides) contacts non-anodized surface at the tailcap.
Precisely machined threads. Two sealing O-rings.
RunTime Performance
This is the section for my usual RunTime test graph revealing the important aspect of the flashlight-its driver performance.
Below is a graph illustrating the measured output in the time. One measurement taken at each second.
I tested the High and the Mid brightness mode. Batteries used for the test-four Keeppower 18650 with capacity of 3400mAh.
Note,that the S1 is positioned as a diving light,so it's performance can benefit to some level from the water cooling,when using it under water.
My lumen measurements-
(My measuring setup is not professionally calibrated,so the provided by me lumen data may differ from actual laboratory tests.)
High= 2400 Lm initial / 2250 Lm after 30sec
Mid= 1360 Lm
Low= 480 Lm
The brightness levels are well spaced,in my opinion.
Thorfire S1 is using a parallel connection scheme of the batteries. This allows a lower current to be drained from each battery,compared to a serially connection scheme.
The total current draw on High mode is about 5,45A (1,36A from each battery).
Current draw in Mid mode 2,75A. Low mode=895mA
The S1 works on High mode without step down interruptions of the graph.
It runs on the highest output,as long as the batteries can keep their voltage.
This tell us.that IMR batteries could improve the overall performance on High mode.
My two tests are done with regular Panasonic core Keeppower 3400 batteries,which I use in most of my reviews.
As expected from a parallel connected battery power source,the output is decreasing with the voltage,clearly visible from the yellow curve.
Restarting the light after some use,will also give you lower initial brightness.
Yet,the performance is still great with the brightness staying above 2000 lumens for about 40 minutes.
Mid mode also shows gradual decreasing ,but in more linear form.
Thorfire S1 features Low voltage warning and protection. The thick line in the end of both curves is formed by the flashing warning light.
At the end of each test,the remaining battery voltage was about 2,8V
The protection in the batteries was not activated.
The S1's head was hot while working on High mode for few minutes. It remained hot above 2000 Lm.
Once the output drops bellow 2000 Lm,the temperature drops to a comfortable warm temperature.
The head has quite enough mass to deal with the programmed output levels.
I did not test it underwater,but for sure there heat dissipation will be much more effective.
Because of the smooth reflective surface of the reflectors,the beam is not absolutely homogeneous in the center,
but I really can't complain and I could even say this is one of the better and quite pleasant flashlight beams I have tested.
Difference in the beam pattern is mostly visible when 'hunting' on a white wall. Outdoors the beam looks impressively well.
The three reflectors focus their beams in one symmetrical round point. It's hard to tell that this is a beam from a multi-LED source.
S1's beam is formed of three zones-bright hotspot,corona and wide spill.
Check out the beamshots below and the outdoor beamshots at the end of the review to get more ideas for the look of the beam.
1 meter, 1/20sec, White wall
1 meter
1/125sec
1 meter 1/500s
1meter 1/1600s
3 meters
1/6sec
3 meters 1/50sec
3 meters 1/250sec
3 meters 1/1000sec
Outdoors
Clearly visible on the pictures,the S1's beam has darker rings in the beam's periphery.
I did not find them disturbing,but this may depend on the subjects/area of illumination and what is the personal requirement to the spill of the beam.
pointed down
pointed up
Additional animated comparisons.
Thorfire S1 - Nitecore TM03 - Nitecore EC4S- Nitecore TM16
Thorfire S1 vs Nitecore TM16
My impressions of Thorfire S1 are only good after using it for some time. It performs quite well.I could even say that it performs better than I expected. Really good beam with very pleasant NW light,very convenient magnetic control ring-easy to access and to operate.Great build quality. Runtime performance is typical for the power scheme the S1 uses.The form of the curve presenting the High mode is good and I like the lack of timed step down,which allows to use the light on its maximum level for as long as the batteries can maintain it.
The heat is not an issue thanks to the massive aluminum head with lots of cooling fins. The overall max output is not as high as we are used to see in many of the latest lights from other brands,but the lower output makes the flashlight more usable in different ambient conditions and does not force you to lower the output or to turn off the light to prevent overheating.
This is a great light to have on work or any type of outdoor activity requiring strong illumination.
What could be improved is the performance on Mid mode.Honestly,I expected flat regulation for most of the time. This will probably shorten the run time,yet it is good to have the option for absolutely constant brightness of the light.
I have no way to test the S1 under water and I can't provide valuable info for scuba diving enthusiasts.
The S1 seems to have excellent water-sealing design-two O-rings at the disassembling zones,indirect On/Off/mode controlling,yet it is recommended to test your copy before some very serious work under water.
Thanks for reading!
Thanks to Thorfire for providing the S1 for test and review!