In this review I will be looking at the TK15 S2. The updated version of the TK15 has an XP-G S2 LED. The TK15 itself has been around since late 2010, so is it still relevant in this fast moving world of flashlights and ever better LEDs?
This is the second of a series of four detailed reviews of a selection of lights making up the ‘Totally Fenix Hunting Line-Up’. Included in the series will be the TK22 (Reviewed here), TK15 S2, HL30, and the TK75, all of which provide a rounded set of capabilities covering everything you would need while out hunting.
Of course each of these lights stands perfectly well on their own, so this review will be covering the light in its own right, and following the individual reviews there will be a follow-up review covering the hunting applications.
Somehow this is the first time I’ve had a TK15 in my hands. It is a very unassuming design and easily overlooked these days, with so much competition. Once you handle it though, the Fenix quality shines through and the relatively compact head make the light overall seem sleek and easy to carry.
For the purpose of this review, the TK15 was also supplied with a set of Fenix accessories, and this is where the TK15 is also strong. Remote tail switch, coloured filters, lamp adaptor, thread protection ring, belt mount and gun mount all add to the TK15’s versatility.
Pop in a battery and the TK15 continues to show it is not passed its best before date. Though there may be brighter lights that use 1 x 18650, but the TK15 has a good, bright, throwy beam, with the XP-G S2 giving a good account of itself.
What is in the box:
The TK15 S2 arrives in the typical Fenix packaging, a very good standard of presentation.
Included are the TK15 S2 with pocket clip and tactical grip ring fitted, nylon holster, instructions, lanyard, two spare o-rings and a spare rubber switch boot.
Taking a closer look and looking inside:
As it comes out of the box, the TK15 S2 has the pocket clip and tactical grip ring fitted.
The clip is well finished with no sharp edges so it won’t be cutting up your pocket (though the knurling might wear the fabric a bit)
The tail cap switch has crenulations.
But these are not tall enough to allow for tail standing as the button protrudes.
A closer look at the LED and reflector surface.
And looking dead-on into the lens.
Both the head and tail-cap unscrew, showing the quality threads and single o-ring at each end of the battery tube.
The negative terminal in the tail-cap is a spring.
The trademark trapezoid threads used in most Fenix lights are cut precisely and fully anodised.
In the head, the positive contact is also a spring, providing excellent shock protection and ensures reliable terminal contact for the battery.
The TK15 S2 can have several different configurations. Here the clip and tactical grip ring have been removed. Also shown here is the optional thread cover to use if you decide to take the tactical grip-ring off, as without the grip-ring, there are some exposed threads.
Here the TK15 S2 has been made ready to slide into the Fenix gun mount.
A small line-up to compare the size of the TK15 S2 with a few of its peers (including the TK22). The TK15 does have a smaller head than most and this makes it feels very compact compared to similar lights. This also makes it really easy to gun mount as the smaller head causes less issues with clearance.
A special section in honour of the TK15 S2’s set of accessories that expand its functionality.
To cover the exposed threads when the grip ring is removed, there are two colours of optional thread covers available.
To go with the use as a gun mounted light, Fenix make one of the best remote switches I’ve used. The AR102 replacement tail cap switch has not only the robust remote pressure pad switch, but also a clicky switch built in, so you still maintain the ability to latch the output on without having to press the remote switch. This dual function means you don’t have to choose between only momentary pressure switch operation and continuous output, the AR102 gives you both.
The Fenix gun mount fits a picatinny rail (or weaver), and includes a sleeve to allow it to mount 25.4mm tubes and slightly smaller ones using the sleeve.
The design has three ‘fingers’ which are independently adjustable. The middle one grips the light, and the two outer ones clamp onto the rail.
If you would also like a lantern you can hang inside a tent or other working/living space, the TK15 S2 has a lantern adapter. This has a shaped reflector to spread out the normally focussed beam and send it into the 360º diffuser.
This has a hanging loop.
The lantern adaptor has fingers which lock into the groove round the TK15 S2’s head and give a very firm grip.
If you like a bit of colour, for hunting purposes, or just for fun, there are great quality red, green and blue filters that slide onto the TK15 S2’s head snugly.
The last accessory in this group is an interesting belt holder. I refrain form using the word holster and this holder is designed to hold the light firmly so it doesn’t fall out. The AB02 has a stainless steel belt clip, and once attached, the holder rotates in 45º increments to allow you to angle the light where you want it.
There is an elasticated tube into which the light body slips and a tightening strap to secure it.
So with these your TK15 S2 can be a flashlight, gun light with remote pressure switch, red, green or blue coloured hunting light, belt mounted work light and lantern in one.
Modes and User Interface:
To control the TK15 S2 there is the forward-clicky tail switch, and the mode selection switch just behind the head.
Click on (or half press for momentary action) the tail switch to access the last used mode. With the tail switch on, press the mode button to cycle though the modes.
The standard modes are Low, Medium, High and Turbo (Turbo automatically goes back to High after 32 minutes).
There is a hidden Strobe mode accessed by holding the modes selection switch in for 1s.
Batteries and output:
The TK15 S2 can run on 2xCR123 or 1x 18650.
For the purpose of keeping this review, and the other reviews in this series ‘Totally Fenix’, the TK15 S2 is being powered by the Fenix ARB-L2 protected 18650 battery, charged using the Fenix ARE-C1 charger.
The testing was carried out with Fenix ARB-L2 18650 cells and CR123 primary cells.
To measure actual output, I built an integrating sphere. See here for more detail. The sensor registers visible light only (so Infra-Red and Ultra-Violet will not be measured).
Please note, all quoted lumen figures are from a DIY integrating sphere, and according to ANSI standards. Although every effort is made to give as accurate a result as possible, they should be taken as an estimate only. The results can be used to compare outputs in this review and others I have published.
Fenix TK15 S2 using ARB-L2 I.S. measured ANSI output Lumens PWM frequency (Hz) Turbo 412 0 High 174 0 Medium 60 0 Low 8 0
Strobe is a dual frequency swapping between 6.66Hz and 16Hz
(Turbo on CR123 was 409lm)
All output modes are free of any sign of PWM.
Out of interest, I decided to see what the output would measure when using each of the coloured filters.
Fenix TK15 S2 using ARB-L2 I.S. measured ANSI output Lumens PWM frequency (Hz) Turbo with Green filter 70 0 Turbo with Blue filter 53 0 Turbo with Red filter 51 0
Of course, filtering white light to give a specific colour is very inefficient but the output is still very usable.
The runtime graph was intended to capture the maximum output. This meant having to babysit the test as every 32 minutes it switches down to High and needs to be nudged back up to Turbo. After doing this, the following output trace is the result.
After the initial drop, it stabilises at 412lm and maintains this with great consistency until after 48 minutes when this level of output cannot be maintained by the 18650 cell.
In The Lab
NEW for Winter 2012 ANSI standards include maximum beam range. This is the distance at which the intensity of light from an emitter falls to 0.25lux (roughly the same as the lux from a full moon). This standard refers only to the peak beam range (a one dimensional quantity), so I am expanding on this and applying the same methodology across the entire width of the beam. From this data it is possible to plot a two-dimensional ‘beam range profile’ diagram which represents the shape of the illuminated area.
In order to accurately capture this information a test rig was constructed which allows a lux meter to be positioned 1m from the lens and a series of readings to be taken at various angles out from the centre line of the beam. As the rig defines a quadrant of a circle with a radius of 1m, all the readings are taken 1m from the lens, so measuring the true spherical light intensity. The rig was designed to minimise its influence on the readings with baffles added to shield the lux meter from possible reflections off the support members.
The distance of 1m was chosen as at this distance 1lux = 1 candela and the maximum beam range is then calculated as the SQRT(Candela/0.25) for each angle of emission.
In this plot, the calculated ANSI beam ranges are plotted as if viewed from above (for some lights there may also be a side view produced) using a CAD package to give the precise 'shape' of the beam.
Starting with the 5m range grid, the TK15 S2’s beam profile is relatively narrow in keeping with its focus on throw.
Zooming out to the 50m grid and here, the TK15 S2 is shown with two other Fenix lights that will be part of this series of reviews. The TK15 S2’s reach is excellent, and the narrow beam reduces distracting spill light that could blind you to the full reach of the light.
The indoor beamshot shows the strong hotspot with some usable spill.
The TK15 S2’s narrow beam reduces distracting spill light that could blind you to the full reach of the light so the TK15 S2 is an effective thrower without the beam being too narrow and difficult to use.
What it is really like to use…
So, the TK15 may have been in the Fenix range for a while and the specifications may not make it stand out from the latest and greatest performers, but the TK15 is a quietly strong performer.
The compact head makes it seem quite a lot smaller and lighter than much of the competition, and yet the performance is not diminished at all.
Fenix build quality is again clearly evident and with the finish being precise and crisp, it makes the TK15 S2 very enjoyable to handle.
As every mode is entirely PWM free, the TK15 S2 is very easy on the eye and comfortable to use for long periods on any output level.
Like the TK22 reviewed previously, the TK15 S2 appears to have a soft turn on and off, where the output quickly ramps up to the chosen level and back down again when going off. This is quick and almost imperceptible, but lends the TK15 S2 a more refined feel in its operation.
I didn’t expect much from the unassuming TK15, but throughout the technical testing and when using this light, I have been very impressed with it. The range of accessories provides extended capabilities and helps the TK15 excel at versatility.
Test sample provided by Fenix for review.