# Fenix TK61vn (XM-L2, 4x18650/8xCR123A) Dedome Modded Review: BEAMSHOTS, RUNTIME+



## selfbuilt (Apr 11, 2014)

*Warning: even more pic heavy than usual. *

_*Reviewer's Note:* This is my first review of custom modified light – in this case, from the well-known CPF modder Vinh Nguyen. For more information on Vinh's lights, please check out the vinhnguyen54 subforum of the CPF Custom Flashlight Builders and Modders forum._















The TK61vn is currently the farthest throwing reflector light that Vinh makes. He has sent me a sample of his top-line TK61vn model, with the 6500K Dedome PDT ("premium dedome tint"). See the spec descriptions for more info on what that all means. 

Again, this is a full review of a _modified_ TK61 (known as the TK61vn). While not intended to serve as a review of the stock TK61, I have picked one up to provide direct output/throw/runtime/beamshot comparisons. Given that the physical build is pretty much the same for external appearances, you should be able to figure out everything you need to know about the stock TK61 from this review as well. 

For more information about the TK61vn specifically, please see Vinh Nguyen's TK61vn discussion thread here on CPF. 

Let's see how the modified TK61vn compares to the stock form, and to other high-output throwers in my collection. :wave:

*Stock Fenix TK61 Reported Specifications:* 


LED: Cree XM-L2 (U2)
Uses four 18650 rechargeable Li-ion batteries or eight CR123A Lithium batteries
Output mode / Runtime: 
Turbo: 1000 lumens / 4h 20min
High: 400 lumens / 14h
Mid: 130 lumens / 46h
Low: 20 lumens / 300h
Strobe: 1000 lumens
SOS: 130 lumens
Beam Distance: 824m
Beam Intensity: 170,000cd
Digitally regulated output - maintains constant brightness
Reverse polarity protection, to protect from improper battery installation
Over heat protection to avoid high-temperature of the surface
Dual switches on the head for fast and convenient operation
Made of durable aircraft-grade aluminum
Premium Type III hard-anodized anti-abrasive finish
Toughened ultra-clear glass lens with anti-reflective coating
Impact Resistance: 1m
Waterproof: IPX-8, underwater 2m
Dimensions: Length: 8.5" / 216mm, Body Diameter: 2.07" / 52.5mm, Head Diameter: 3.8" / 96mm
Weight:21.12oz / 600gm
MSRP: $160
*Vinh Nguyen TK61vn Reported Specifications:* (where different from above) 


LED: XM-L2 6500K Dedome (see other options below)
Output mode: Test Done by CPF Member rdrfronty
Turbo (30 sec.) - 1735 lumens
High - 840 lumens
Medium - 332 lumens
Low - 53 lumens
Beam Distance: 1577m
Beam Intensity: 622,000cd
Factory 3.1A boosted to 5.75A
Battery carrier tweak
Tune for best focused beam
New electrical components added to handle high current draw
Crucial high heat electrical components cooled with thermal pad
Light will get uncomfortably hot around 10 minutes. Please throttle down at this point.
Price / Options:
6500K Dome On $240
6500K Dedome $255
6500K Dedome PDT $270 _(Reviewer's note: this is the sample reviewed here)_ 
4500K Dome On $250
4500K Dedome $255
_*Note:* As always, these specs are simply what Fenix and Vinh Nguyen provide – scroll down to see my actual testing results._






Packaging is fairly standard for Fenix. The large cardboard box has key performance and use specifications printed right on the outside. Inside, in sturdy packing foam, you will find the light, extra o-rings, basic should strap, simply wrist lanyard, manual, and product inserts. As you can see in the opening pics to this review, my TK61vn came with a little thank you note from Vinh as well. 













From left to right: AW Protected 18650 2200mAh; Fenix TK61vn, TK75; Fenix TK51; Niwalker Vostro BK-FA01; Thrunite TN35. 

All dimensions directly measured, and given with no batteries installed (unless indicated):

*Fenix TK61vn*: Weight: 608.0g (792g with 4x18650), Length: 218mm, Width (bezel): 96.0mm
*Fenix TK61*: Weight: 605.7g (790g with 4x18650), Length: 218mm, Width (bezel): 96.0mm
*Fenix TK75*: Weight: 516.0g (700g with 4x18650), Length: 184mm, Width (bezel): 87.5mm
*ArmyTek Barracuda (XM-L2)*: Weight 400.8g, Length 264mm, Width (bezel): 64.0mm 
*Eagletac MX25L2 Turbo (SBT-70)*:Weight: 698.6g (with battery pack: 974.1g), Length: 292mm, Width (bezel): 91.3mm
*Niwalker BK-FA01 (XM-L2)*: Weight: 682.3g (864g with 4x18650), Length: 209mm, Width (bezel): 80.0mm, Width (tailcap): 50.3mm
*Olight SR95S-UT (SBT-70):* Weight: 1,208g (with battery pack), Length: 323mm, Width (bezel): 87mm
*Olight SR95-UT (SBT-90):* Weight: 1,221g (with battery pack), Length: 323mm, Width (bezel): 87mm
*Skilhunt K30-GT (SBT-90):* Weight: 635.9g (773g with 3x18650), Length: 199m, Width (bezel): 76.0mm
*Thrunite TN32 (XM-L2)*: Weight: 655.9g (808g with 3x18650), Length: 201mm, Width (bezel): 79.0mm

As you can see, the overall design is reminiscent of the multi-emitter TK75 – only with a much larger head for that deep-throwing reflector. 






















The TK61vn is a substantial light, with a solid look and feel. As with other recent TK-series lights, anodizing is a flat black, and seems in very good shape on both my stock TK61 and TK61vn. Whatever modifications Vinh has done to the light, he has not marred the finish on my TK61vn. :thumbsup:

Stock TK61 body labels are fairly minimal, but clearly legible (except for the temperature warning, which is oddly printed on an uneven region). Again consistent with the TK-series, there is no knurling per se on the light. However, the checkered pattern on the handle has been updated, and is raised compared to earlier TK-series lights (helping considerably with grip). Combined with the other build elements and ridge detail, you should find overall grip good. Threads are square-cut, and generally seem of good quality. 

There is a shoulder attachment strap ring located in the head area (that rotates around). Combined with the attachment points in the tailcap, you should be able to carry it securely in this fashion. 

The TK61 can tailstand stably, thanks to its raised cutouts. As you can see on my TK61vn, Vinh has done a nice job hand-engraving his logo. This is the only obvious indication that the light has been modded (well, aside from the dedomed emitter – but we'll get to that). 

The TK61 uses electronic switches in the head to control on/off and mode switching. The right switch controls on/off, and the left controls output level selection. Switch feel is good, and there is a definite "click" when making full contact. Scroll down for a discussion of the user interface.

Inside the head, the circuit board is clearly visible there are two contact rings for the positive and negative current paths of the carrier. Again, no obvious signs that my TK61vn has been dissembled and rebuilt.  The contact points in the stock TK61 look more robust than my earlier TK75.

Let's look at the carrier (from the modded TK61vn):






















Here you can see some of the first signs of Vinh's modifications. Note that the stock TK61 carrier looks the same as the TK75 that I recently reviewed (see that review for stock pics). 

I can see that Vinh has added an additional contact path inside each carrier well spring, soldered at the base and tip of the springs (likely to ensure good consistent current flow). This must be part of the "carrier tweaks" Vinh refers to.  There was also been some red permanent marker transfer to the white carrier body (likely from cells that were previously installed – I cleaned most of these off with a bit of alcohol).

In general terms, the TK61/TK61vn carrier plastic is nice and thick, with a sturdy feel. The bays appear wide enough to accommodate a wide range of cell diameters, and I had no problem fitting the loaded carrier into the light with any of my cells. You may find longer cells a bit tight in the carrier, however. The raised contact disc at the positive terminal means flat-top cells will work fine. As before, I like the slight cut-outs near the positive terminals, to facilitate getting your cells out. 

The carrier is organized in a 2s2p arrangement. This means that you could easily run 2x18650 cells in a pinch, as long they as they were located in adjoining cells to appropriately complete a circuit (i.e., side-by-side bays, with one pointing up and the other pointing down, as indicated by the carrier). 

 I STRONGLY recommend against trying to run the TK61vn on anything but the full complement of 4x18650, given how heavily driven this modified light is (although I suppose 2x IMR 18650 may be able to handle it). On a stock TK61, you should be able to get away with 2x18650 more easily. 

The TK61 also supports 8xCR123A (and could probably handle 4xCR123A in a pinch). Again, I recommend exercising common sense with the modded TK61vn – the light and cells will heat up on Turbo, so sustained runtime on CR123A is NOT recommended.

Let's take a look at the head of my dedomed TK61vn:


















Vinh sent me an example of his XM-L2 "premium dedome tint (PDT)", which he estimates to have ~5000K color temperature. As you can see in the pics above, dedoming the emitter gives you a clear view of the underlying die. 

For a comparison, here is what the stock TK61 XM-L2 emitter looks like, with the exact same magnification as the last pic above:






The presence of the stock dome distorts the view of the emitter, of course, greatly magnifying it. Note that the emitter die centering was perfect on my TK61vn, and was only "good" on my stock TK61 (i.e., not perfectly centered, but not bad). This is again one of the benefits on a custom mod – everything is adjusted for absolute best performance. :thumbsup: 

Note that dedoming will improve peak beam intensity, but will likely also shorten the lifespan of your emitter. 

The smooth reflector is massive on the TK61, which explains its outstanding throw. Some "tuning" of the focusing is done to maximize throw on the TK61vn (which I presume means some adjustment of the positioning of the reflector). There is a good quality anti-glare coating on the lens of the light (unchanged). The light also has a scalloped bezel ring,

Scroll down for beamshots. :wave:

*User Interface*

Similar to the TK75 (but updated slightly), the TK61 uses two electronic switches to control on/off and mode selection. These are located just under head. The right button is the main On/Off switch, the left button is the output mode selection switch.

For constant on (or off), click the right power switch. A new feature on the TK61 is that you can also press-and-hold the power switch from off for momentary access to Turbo (more on this below). 

When in constant on mode, click the left button to advance through the output modes. The TK61 has four main output levels, accessed in repeating sequence: Lo > Med > Hi > Turbo. The light has output level memory, and will come back on at whatever level you last turned it off in.

The light also has strobe/SOS modes, but these are "hidden" away from the main sequence. To access these flashing modes, press and hold the left button. If you hold the button down for ~2 secs, you will get a tactical strobe mode. If you hold the button down for >4 secs, you will get a lower output SOS mode. Release the left button to select your flashing mode (i.e., locked on). You can click the left button to return to the last constant output mode (or turn off/on by the right button). There is no mode memory for the flashing modes.

As with the TK75, you can access the strobe/SOS modes from off by pressing and holding the left button. But new on the TK61 is the ability to jump to a true momentary Turbo mode by holding down the right power button from off (i.e., press for momentary – release, and it turns back off).

However, as many others have reported here on CPF, some TK61 samples are variable in how long they will let you stay in momentary Turbo, even on fresh batteries. The light is supposed to stay on as long as you hold down the power button. But on my TK61vn, the light shuts off anywhere after 1-10 secs (despite continuing to hold down the power button). My stock TK61 does a little better, between 3-25 secs before randomly shutting down. Cause is unknown, but it doesn't affect any other function of the light. As a potential workaround for those affected, holding down the mode button once in momentary (and then releasing the power button) allows you to maintain an indefinite momentary Turbo (until you release the mode button). I presume Fenix is working to fix this particular bug. :shrug: 

*Video*: 

For more information on the overall build and user interface of my TK61vn, please see my video overview:



As with all my videos, I recommend you have annotations turned on. I commonly update the commentary with additional information or clarifications before publicly releasing the video.

*PWM/Strobe*

There is no sign of PWM on any level – I believe the TK61 is current-controlled, like other Fenix TK-series lights.  I did detect some low-frequency oscillations on Lo/Med/Hi (but not Turbo):

Noise:





Note that circuit noise is common on many current-controlled lights, and has nothing to do with the modification here. It does not affect performance, nor is it detectable visually. As per my usual review policy, I simply report on all circuit features that I can detect – it doesn't mean they are significant in use. Rest assured, the TK61/TK61vn are flicker-free in use, at all levels.

Strobe:





As with other Fenix TK-series lights, strobe is an oscillating frequency strobe, switching between 6.5Hz and 15.3Hz on my sample. Each frequency lasts for about ~2 secs. Here is a blow-up of each strobe frequency individually:










Strobe pulse width is a little unusual, but it doesn't really change how disorienting this strobe is.

*Standby Drain*

Due to the electronic switch, the TK61 will always be drawing a small current when the carrier is connected to the head. I measured this current as 1.2uA on my stock TK61 sample. On my TK61vn, it was too low to get a reliable DMM reading. oo:

As a result, the standby drain is completely negligible (i.e., it is well below the normal self-discharge rate of Li-ions). Note that like on the TK75, the carrier is in a 2s2p carrier arrangement. 

However, you are not easily able to lock out the switch to prevent accidental activation. There is no electronic lock-out on this model, and unscrewing the head doesn't help much (i.e., it is the tension on the springs in the carrier that makes contact). You need to unscrew the tailcap several full turns to reliably lock out the light.

*Beamshots:*

And now, what you have all been waiting for.  All lights are on their standard battery, or AW protected 18650 2200mAh for the multi-18650 lights. Lights are about ~0.75 meter from a white wall (with the camera ~1.25 meters back from the wall). 

Automatic white balance is used on the camera, to help minimize tint differences. 





























































_Rest assured – my TK61vn is not green in real life! _ It is difficult to accurately capture tint using a camera's auto white balance. That said, the dedomed PDT TK61vn is indeed warmer than cool white. I would say Vinh's ~5000K estimate is pretty good (on Turbo) – I would describe it as "creamy yellow". 

Note however that for current-controlled lights, the tint shifts further to the warm end of the spectrum at the lower drive levels. This characteristic is exacerbated by dedoming. I do find indeed find my TK61vn to be slightly green at the Lo/Med levels (not noticeable on my stock TK61).

As for the beam, it's obviously hard to tell much at such ridiculously close distances.  The tint difference also makes it hard to compare overall output in these pics - in real life, the TK61vn is definitely brighter overall.

As for the throw, it is hard to draw too many conclusions from these pics. Even at the maximum shutter speed of my camera, the hotspots are over-saturated. But you can probably tell that the TK61vn is more sharply focused (i.e., more defined hotspot edge, with less corona). To tell more, we are going to have to go out to further distances ... 

Here are some indoor shots in my basement. For your reference, the back of the couch is about 7 feet away (~2.3m) from the opening of the light, and the far wall is about 18 feet away (~5.9m). Below I am showing a couple of exposures, to allow you to better compare hotspot and spill. 

Let's see how the TK61vn compares to the stock TK61, and my more recent 1xXM-L2 throw champ, the Thrunite TN32.


















Ok, that makes it a lot clearer – the TK61vn has MUCH greater peak hotspot intensity than either the stock TK61 or TN32. oo:

The stock TK61 is fairly close to the peak intensity of TN32 (although the TN32 definitely has more overall output). 

As you can also tell above, the TK61vn has more output overall, relative to the stock TK61. The camera's automatic white balance is also doing a better job of capturing the "feel" of the tint difference – but I caution again that these are never wholly accurate on a camera.

Of course, you would not be buying this light to explore the inside of your house.  I need to do outdoor beamshots, but the snow has only finally melted this week. Give me a couple of weeks, and I'll update this thread with beamshots. :wave:

*UPDATE May 17, 2014:* Weather conditions have finally improved enough to start taking outdoor beamshots around here. To start, here is a comparison of the TK61vn to the stock form and the Thrunite TN32. I plan to add additional comparisons over the comping weeks, as I bring out some new lights to test.

As always, these are done in the style of my earlier 100-yard round-up review. Please see that thread for a discussion of the topography (i.e. the road dips in the distance, to better show you the corona in the mid-ground). 











As you can see, the V54 mod and dedoming hugely increases center-beam throw. oo: You can see why this build was a good choice for this mod, as even the stock TK61 has a very focused beam. As you can also tell from above, the stock TN32 has greater output than the stock TK61 (this is another selling point in favor of the V54 mod, as overall output similarly increases).

*Testing Method:* 

All my output numbers are relative for my home-made light box setup, as described on my flashlightreviews.ca website. You can directly compare all my relative output values from different reviews - i.e. an output value of "10" in one graph is the same as "10" in another. All runtimes are done under a cooling fan, except for any extended run Lo/Min modes (i.e. >12 hours) which are done without cooling.

I have devised a method for converting my lightbox relative output values (ROV) to estimated Lumens. See my How to convert Selfbuilt's Lightbox values to Lumens thread for more info. 

*Throw/Output Summary Chart:*

My summary tables are reported in a manner consistent with the ANSI FL-1 standard for flashlight testing. Please see http://www.flashlightreviews.ca/FL1.htm for a discussion, and a description of all the terms used in these tables. Effective July 2012, I have updated all my Peak Intensity/Beam Distance measures with a NIST-certified Extech EA31 lightmeter (orange highlights).






Ok, here's the top line: my TK61vn has ~600,000cd by ANSI FL-1 measures, making it the furthest throwing reflector light I've ever tested. 

The stock TK61 came in right on the nose of the official specs, at ~170,000cd. This means that the modifications done by Vinh have increase peak beam intensity to 3.5 times the stock light (i.e., a 250% increase over the stock beam). oo: Since light decays by an inverse square law, that means that beam distance has not quite doubled (but it is close to that).

The TK61vn has a remarkably tight (i.e., small) hotspot at 10m (which the ANSI FL-1 testing distance). It is possible that a further distance could provide more reliable indicators for such heavy throwers, but I have not personally experimented with non-ANSI measures.

Let's look at overall output:






As always, I don't insist on the _absolute_ value lumen estimate for these large lights (since they don't fit in my calibrated lightbox). But my estimation method is consistent for _relative_ output across all my reviews. And as you can see above, my method gives me a nearly perfect concordance with Fenix's specs for my stock TK61 sample. As such, I trust that my measures of the TK61vn are relatively consistent. 

I also note that my direct throw measures and lumen estimates on Turbo are slightly lower than those reported in Vinh's TK61vn thread (as measured by rdrfronty here). But the difference is not great, and likely fits well within natural variation among modded lights. Also, Vinh informs me that rdrfronty had a "Factory LED Dedome", which would have been cooler tint than my sample. While that should not affect peak beam intensity, there may be some variation in lux meter sensitivity to different tint ranges. Again, my throw measures are done with a NIST-certified light meter under ANSI FL-1 testing conditions (i.e., working back from 10m). And ~600,000cd is an outstanding result under those conditions. 

To look at it another way, that's a 250% increase in throw on my TK61vn, with only a ~65% increase in overall output, from stock. :bow:

*Output/Runtime Graphs:*

Since the modded TK61vn is driven harder at all output levels - and there is no automatic thermal step-down on this model - Vinh recommends throttling down manual after ~10 mins of continuous runtime on Turbo. This is a reasonable precaution to me, as the light will get warm by this point. 

All my runtime testing is always conducted under a cooling fan, for safety and consistency reasons. Surface temperature of the TK61vn remained reasonable after 10 mins of continuous Turbo runtime in my testing (i.e., never exceeded 47 degrees C surface temp at the hottest point at the base of the head). Nevertheless, I decided to follow Vinh's stated recommendations, and paused the Turbo runtimes after ~10 mins runtime. Once the TK61vn had re-cooled back to room temp, I restarted the runs. I have edited the traces below to only show you the "on times", with a spike at off/on time points. This should give you a pretty good idea of what continuous runtime would be like, should you attempt it (against advice).










As you would expect, overall output/runtime efficiency is not affected by the mod. The difference is in how much brighter the TK61vn is at each level. 

The TK61 shows a clear step-wise step-down regulation pattern as the batteries drain. This is a convenient way of letting you know when it is time to change cells (well, when running at higher outputs at any rate). Regulation is very flat-stabilized.

In the case of the Turbo mode run, I got a little over half an hour before the TK61vn stepped down to Hi. Note again that I paused the runs at each the spikes above (pause time not shown), to allow the light to cool.

Let's see how it does against the competition …










The TK61 is a very efficient current-controlled light for this class – as is the TK61vn. The Thrunite TN32 remains the most efficient example I've seen to date, though.

*General TK61 Potential Issues*

The TK61 lacks any sort of electronic lock-out mode, and a physical lock-out requires several turns of the handle (to break the tension on the carrier springs). While not a concern for standby drain (which is negligible, well below the self-discharge rate of the batteries), lack of a robust lock-out is a potential issue for accidental activation. 

My TK61 samples are inconsistent in the momentary Turbo feature (as has already been reported here on CPF). This was a new feature added to the TK-series, and it looks like Fenix still has some bugs to sort out.

The included shoulder strap/lanyard accessories are very basic. Despite the size, I expect most users would like a good quality holster.

Noticeable warm tint-shifting is possible at lower output levels on all current-controlled lights. I have commonly found a fair of amount of noticeable green tint on the lowest modes of many Fenix XM-L/XM-L2 lights. However, my stock TK61 was quite cool-tinted on Turbo (with a slight purplish hue), and I didn't notice anything significant when downshifting in this case.

*TK61vn Potential Issues*

The TK61vn is driven harder at all levels, so care should be taken not to overheat the light by sustained runtimes on Turbo (i.e., there is no built-in thermal step-down on this model series). If the light feels uncomfortably warm, you will need to throttle down manually.

Typically, dedoming an emitter tends to produce a warmer overall beam tint. The "premium dedome tint (PDT)" version of the TK61vn guarantees a more consistently neutral ~5000K tint on Turbo. However, my PDT version had a noticeable green-tint when downshifting levels (especially on Lo/Med). Vinh informs me that this green tint shifting is typically worse on non-PDT dedome versions (which usually have a cooler white tint to start with on Turbo). 

Long-term reliability of any modded light is unknown, but it stands to reason the modifications for maximum performance here could shorten component life span (especially on the dedomed version). That said, Vinh also shores up a number of circuit components during his mods, which may increase overall useable lifespan of the light. Of course, modding voids all manufacturer warranties, but I understand that Vinh stands behind his products.

*Preliminary Observations*

The TK61vn is the top-throwing reflector light I've tested to date, bar none. ~600,000cd is an incredibly beam intensity. :bow:

The stock TK61 from Fenix is good thrower light in its own right, with consistently accurate specs and performance. As with most of the Fenix line, the TK61 has flat stabilization (regulation) at all levels, with excellent output/runtime efficiency. It is also one of the "throwiest" XM-L2 lights in stock form, second only to the Thrunite TN32 in my testing. If Fenix could have driven the emitter as hard as the TN32, I have no doubt the TK61 would have overtaken the stock XM-L2 on throw.

Which brings us around to why this is such an attractive build for modding. 

With some circuit tweaks to boost current – supported by upgrades to the circuit/carrier wiring and additional heatsinking – you would have the potential to push the TK61 much further. This is basically what Thrunite did on its TN32 model – they upgraded the standard TN31 components to produce the top stock XM-L2 throw king.

Of course, a custom mod can always do more than what a factory-produced light is capable of. A good example here is dedoming the emitter. When done carefully, this has the potential of greatly improving peak throw. A custom mod can also tweak the reflector focusing of each sample, for maximum throw. Put that all together, and I think you can see why conditions are ripe for some expert modification and enhancement on the TK61. Enter the TK61vn reviewed here, modded by CPF user vinhnguyen54. Vinh has a large following in the modders forum, and the TK61vn is currently his furthest throwing mod.

How well does this light throw? Well, peak beam intensity is ~3.5 times the stock TK61. oo: That corresponds to ~3 times the stock TN32, and more than twice that of my previous peak throwers, the SBT-70-equipped Olight ST95S-UT and Eagletac MX25L2 Turbo. As an aside, the SBT-70 is almost like a factory-dedomed SST-90 (only with a thin protective covering, and rounded die edges for improved focusing). But the smaller die XM-L2 – when dedomed - has a definite edge when driven to the same overall output level.

So what is the downside to doing this? Well, modding obviously voids all manufacturer warranties, and tweaking all the components may shorten their lifespans (although by the same token, Vinh also upgrades internal components, and corrects potential stock issues). There is presumably a reason why LED makers install a dome over their emitters in the first place - part of it is esthetics (i.e., beam pattern artifacts and tint shifting are reduced by the dome), but part of it may be long-term reliability and stability of the emitter. That said, in my experience the vast majority of LED flashlight failures are due to circuit components, not emitters - and I understand that Vinh stands behind his mods. In any case, I suppose none of that matters for those looking for the ultimate thrower hot-rod – zoom, zoom. :laughing:

Output/runtime performance of the modded TK61vn remains excellent – all that has really changed here is the drive level of each mode, and the amount the beam throws. See the tables, figures and beamshots in this review for a comparison.

Please check out Vinh's TK61vn discussion thread here in the modders forum for more info on this light (and tons more beamshot comparisons). If you are comfortable going the modded light route, the TK61vn is the clear throw king in my testing at the moment. :wave:

----

TK61vn was provided by Vinh Nguyen for review. Stock TK61 was purchased from a local vendor.


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## AbbyY (Apr 11, 2014)

Thank you for review!


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## Wiggle (Apr 11, 2014)

Great review . I have the slightly lower (but still very high) specced K50vn PDT on the way. It is very cool to see one of vinh's lights properly compared to the stock versions and other super-throwers. I am very much looking forward to the long distance beamshots.


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## Swedpat (Apr 11, 2014)

Thanks for the review Selfbuilt!

I am totally ignorant when it come to this special mod. Is the lens of the LED removed, is it what makes the main increase of throw?


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## Wiggle (Apr 11, 2014)

Swedpat said:


> Thanks for the review Selfbuilt!
> 
> I am totally ignorant when it come to this special mod. Is the lens of the LED removed, is it what makes the main increase of throw?



The removal of the lens is a big part. It makes the LED apparent size significantly smaller (as you can see in the pictures). A general rule of throw is that smaller dies with higher surface brightness produces more throw. The other side of the mod would be the general increase of output due to increased current drive levels.

It should also be noted that removing the dome affects the colour temperature, generally shifting it towards the warmer side by 1000-2000K. That is why this light is estimated to be around 5000K when the LED itself was a 6500K version.


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## Swedpat (Apr 11, 2014)

Thanks for the info Wiggle! Interesting.


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## Tmack (Apr 11, 2014)

I'm a proud owner of a tk61vn and have been anxiously awaiting this review. Thanks very much for your hard work. 
This light is surly an amazing accomplishment by vinh, and is a pleasure to use. I absolutely love mine


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## jonwkng (Apr 11, 2014)

Been waiting for this review. Awesome! Especially with the comparisons made with the stock TK61. Great review as always, *selfbuilt*!

Hope to see more reviews of Vinh's lights in the future... *cough* MM15Vn *cough*


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## selfbuilt (Apr 11, 2014)

Wiggle said:


> I am very much looking forward to the long distance beamshots.


Coming soon, just waiting for some buds on the trees so everything doesn't look completely dead here. 



Swedpat said:


> I am totally ignorant when it come to this special mod. Is the lens of the LED removed, is it what makes the main increase of throw?


Wiggle summarized it pretty well up above. The stock dome on the emitter helps minimize tint variations across beam angles, and increases the apparent size of the emitter (thus reducing the ability to focus it maximally for throw).

To put it in perspective, the ~65% increase in output on Turbo would normally contribute to an equivalent ~65% increase in peak beam intensity. It is the dedoming of the emitter (and the more precise centering and focusing of the reflector) that is taking you all the rest of the way to the measured ~250% increase peak beam intensity here.

But as Wiggle said, dedoming shifts the overall color temp down noticeably.


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## ven (Apr 11, 2014)

Thank you for one of the most awaited reviews(certainly by me anyway):twothumbs so imo the best reviewer + imo the best modder= WOW good as it gets

Vinh is a genius,not only that he is a really nice guy too,makes the whole package just fantastic.

Your reviews are really in depth and thorough, a joy to read,perfectly written and understandable to people who are not as well educated on all the technicalities(like me):laughing:

Then the pictures,beam shots,just fantastic and appreciated so much.

I cant wait for the outdoor shots once your snow has melted

Look forward to future vinh reviews too,fantastic!!!! and so glad your involved.

On the de-dome part,i have not read any information regarding loosing the life of the led,is there actual evidence to back that up or is it just a well educated presumption,any study etc.Would the higher A cause more of a life time issue than de-dome or a combination maybe of both.Its not something that i thought would effect the led tbh in that way,but i know far less obviously than you

Thank you again selfbuilt:twothumbs


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## selfbuilt (Apr 11, 2014)

ven said:


> On the de-dome part,i have not read any information regarding loosing the life of the led,is there actual evidence to back that up or is it just a well educated presumption,any study etc.Would the higher A cause more of a life time issue than de-dome or a combination maybe of both.Its not something that i thought would effect the led tbh in that way,but i know far less obviously than you


It is an educated guess. Keep in mind that in addition to dedoming, Vinh is also driving the emitter much harder on Turbo. While the extra heatsinking will help, that is still placing a heavier heat burden on the emitter. It simply stands to reason that these factors would accelerate normal "aging" and degredation of the emitter over time. But I don't imagine there are a lot of openly published studies on any given emitter, since most of it would be considered proprietary information by the manufacturers.
_
*EDIT:* That said, the EPA's TM-21 calculator seems to be the general tool that most LED manufacturers use to estimate LED lifetime (although that is really not what it is designed for). Their summary results (based on manufacturer data) clearly show accelerated rates of lumen degradation with sustained higher temperature. That said, the timescales are so long that it is probably not an issue for most._

_Just of a little side-topic interest ... but as mentioned in the review, in my experience, most flashlight failures are due to circuit components, not emitters._


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## Wiggle (Apr 11, 2014)

selfbuilt said:


> To put it in perspective, the ~65% increase in output on Turbo would normally contribute to an equivalent ~65% increase in peak beam intensity. It is the dedoming of the emitter (and the more precise centering and focusing of the reflector) that is taking you all the rest of the way to the measured ~250% increase peak beam intensity here.



One thing I forgot to mention, by dedoming you do reduce the lumen output somewhat. Obviously vinh increased the current enough to offset this (and then some).


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## Capolini (Apr 11, 2014)

I am Lucky "13"!!

Great review!! I also have this torch. It has an awesome display of throw!

It is nice to know your numbers were very similar to what one of the members tested it at. I certainly was not shocked when you mentioned that this is the Longest Throwing torch you ever tested!!

My simple but practical field test amazed me and a friend of mine who really has no interest in torches! She could not believe that I illuminated a water tower from .8 miles/1408yds/1287meters away!! She was amazed as she witnessed the beam from start to finish! It still had 300+ yards of throw left!:twothumbs

Thanks again SB,,,,,,,now I am going to look at the video and read the review again!!


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## metalhead69 (Apr 11, 2014)

I have the vn and now I have the review! Thanks selfbuilt for the review! Awesome Light Awesome Review!!!


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## ven (Apr 11, 2014)

Wiggle said:


> One thing I forgot to mention, by dedoming you do reduce the lumen output somewhat. Obviously vinh increased the current enough to offset this (and then some).




Yes its around 10% loss which in real terms not noticeable.


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## luminositykilledthecat... (Apr 11, 2014)

To all those people who are unsure about Vihns mods, let this amazing review remove all your doubts 
I am the proud owner of many of his creations and each one is awesome. Just awesome.

Selfbuilt your the best. Huge respect and thanks :thumbsup:


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## who (Apr 11, 2014)

Thank you selfbuilt. 
Regarding the longevity and warranty issues, I can share some of my experiences here:
- SureFire stands behind their products, and the shipping is convenient within the USA.
- The rest is random at best. 
- If you buy from a distributor, then you are kind of OK. Even then, a round trip to China and back is forever.
- If not, with a few exceptions, you are on your own.

There are many benefits if one buys from Vinh:
- He will fix up your light in a flash, and you can have it back in a few days.
- In the rare case that some LEDs die prematurely, he will replace them, and you can choose your tint and bin.
- By opening a light to mod, Vinh will fix any QC problem that stays hidden under the surface. Believe me, there are many.
- Later, for a small fee, you can always send your light back for a newer or different LED. Replacing XM-L2 with XP-G2 for throw is one example.


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## InfinitusEquitas (Apr 11, 2014)

Thank you for another great review! I've been waiting for this one quite anxiously, and it's rewarding to see a nice apples to apples comparison of a modded versus stock light.

There seems to be some concern about the reduction of the lifetime of the LED, due to the dedome, and pushing it harder. I think this is a very valid, but for most people essentially irrelevant.

The LEDs are rated for thousands of hours or continuous use. That's just not how flashlights are used. Very few people, especially flashlight enthusiasts, push their lights for use in terms of maximum longevity, so even reducing the lifetime of the LED by a factor of 10, is not likely to be an issue, for all but the most heavy flashlight users.



who said:


> - By opening a light to mod, Vinh will fix any QC problem that stays hidden under the surface. Believe me, there are many.



+1

Wanted to say this as well. 

Vinh does a lot of touch up work on the lights that aren't obvious, but make a big difference. As a matter of course he touches up, and redoes solder points, replaces thin wires with thicker ones, and often fixes serious existing factory quality issues. On a couple of occasions I looked at the lights, before and after mod, opening up the head, and the differences in solder work if nothing else, are big.


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## Ryp (Apr 11, 2014)

Thanks for the review!


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## selfbuilt (Apr 11, 2014)

who said:


> There are many benefits if one buys from Vinh:





InfinitusEquitas said:


> +1 Wanted to say this as well. Vinh does a lot of touch up work on the lights that aren't obvious, but make a big difference. As a matter of course he touches up, and redoes solder points, replaces thin wires with thicker ones, and often fixes serious existing factory quality issues. On a couple of occasions I looked at the lights, before and after mod, opening up the head, and the differences in solder work if nothing else, are big.


These are good points - as is the issue of variability of manufacturer warranty support. On that earlier point, my goal was simply to point out that manufacturer warranties are null and void by modding - if that matters to the end user. As always, I leave it up to the consumer to decide what features of a light matter to them (which is why I generally don't "recommend" lights here, or provide a value ranking scheme). 

As for the latter point, in the interest of being balanced I've amended my two comments in the review as follows: _(italics showing the addition)_

"Long-term reliability of any modded light is unknown, but it stands to reason the modifications for maximum performance here could shorten component life span (especially on the dedomed version). _ That said, Vinh also shores up a number of circuit components during his mods, which may increase overall useable lifespan of the light._ Of course, modding voids all manufacturer warranties, _but I understand that Vinh stands behind his products_."

and

"So what is the downside to doing this? Well, modding obviously voids all manufacturer warranties, and tweaking all the components may shorten their lifespans _(although by the same token, Vinh also upgrades internal components, and corrects potential stock issues)_. ... That said, in my experience the vast majority of LED flashlight failures are due to circuit components, not emitters _- and I understand that Vinh stands behind his mods._"

:wave:



InfinitusEquitas said:


> There seems to be some concern about the reduction of the lifetime of the LED, due to the dedome, and pushing it harder. I think this is a very valid, but for most people essentially irrelevant. The LEDs are rated for thousands of hours or continuous use. That's just not how flashlights are used. Very few people, especially flashlight enthusiasts, push their lights for use in terms of maximum longevity, so even reducing the lifetime of the LED by a factor of 10, is not likely to be an issue, for all but the most heavy flashlight users.


Yes, this is very good point as well - and I agree in principle. If you have an LED rated with a lifetime in the tens of thousands of hours (as most of them are), a slight reduction in that lifespan is immaterial. 

However, I would point out that that lifespan is only an estimate, based on a much lower testing requirement by the TM-21 standard. I am not sure off-hand for this emitter, but I believe it is generally only a few thousand hours (at a relatively low current) that actually gets measured by the manufacturers for each new model. Still, I agree it is likely to be immaterial - other circuit components will likely fail long before the emitter does.

But I also need to consider in my assessment that the relative risk of dedoming is largely a giant unknown (i.e., it could have a much greater impact on emitter degredation). As such - much like warranty comments - I feel I would be remiss if I didn't at least draw the end users attention to this matter, so that they can make their own assessment of the relative risks.

That said, my "gut impression" is that if a dedomed emitter functions stably for the first few hours of continuous use, it is probably not going to be an issue in the regular lifetime of the product. To use a parallel, this is why (in my younger days)  I used to "burn in" all my over-clocked computer equipment with several hours of hard-core torture testing with limited cooling. If the parts didn't experience errors under those conditions, they were likely to be fine for the estimate lifetime of regular use at the elevate clock speeds/timings.

Just to be clear - I don't take any of the community comments above as challenging in any way - I think it was fair to raise them. I don't mean to be overly verbose, but it is just that this is my first review of a commercially modded light, and I want to make sure everyone can see my reasoning and understand where I am coming from. All points of view are welcomed here. :wave:


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## ven (Apr 11, 2014)

Thats why your reviews are 2nd to none selfbuilt,honest,unbiased..............superb:twothumbsand have such a following for detailed opinion,so well communicated.

I agree on that vinh does compensate with beefing up components,as we know manufacturers have to make money,all profits,be it cars or flashlights. Thinner metals on body work ,cheaper parts/components too,to thinner wires,less solder on lights etc etc(just plucked examples).

The added bonus is also vinhs communication and customer service...........i dont know how he does it but he does and surpasses my expectations and some x 10.

As in my 1st post,a great team,reviews and modder,the best imo,just makes CPF all the better.:twothumbs
lovecpf great community :grouphug:

I really look forward to the future relationship with lights and reviews,both with a strong following=excellence at its best.

Regards mr very positive :laughing:


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## who (Apr 11, 2014)

selfbuilt,

Your assessment and precaution are needed.
None of my comments were meant as a challenge to you or anybody else, in any shape or form. Just my observations.


I used to work with MTBF (mean time between failures) a lot in my CPU design days. [FONT=&quot]Like you with over-clocked computers, I played with various CPUs, increase the speed / megahertz, and used all kind of heat sinks to cool those CPUs. Yes, I was one of the guys in the 80386 design team.
[/FONT]

[FONT=&quot]This is a hobby for most of us, and these VN turbo lights put a lot of fun back in this hobby. That said, for anything tactical, I still use the old SureFire lights.
[/FONT]

[FONT=&quot]Thank you again for your great work.[/FONT]


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## InfinitusEquitas (Apr 11, 2014)

selfbuilt said:


> That said, my "gut impression" is that if a dedomed emitter functions stably for the first few hours of continuous use, it is probably not going to be an issue in the regular lifetime of the product. To use a parallel, this is why (in my younger days) I used to "burn in" all my over-clocked computer equipment with several hours of hard-core torture testing with limited cooling. If the parts didn't experience errors under those conditions, they were likely to be fine for the estimate lifetime of regular use at the elevate clock speeds/timings.
> 
> 
> Just to be clear - I don't take any of the community comments above as challenging in any way - I think it was fair to raise them. I don't mean to be overly verbose, but it is just that this is my first review of a commercially modded light, and I want to make sure everyone can see my reasoning and understand where I am coming from. All points of view are welcomed here.




I still do that  Whenever I put together a new computer, or buy a new laptop, or cellphone, I torture test them to far beyond what would be considered normal use.

Thank you for understanding, and even more so for updating your review, I thought it was very fair and balanced to begin with, but is even more so now. I'm certainly not out to contradict/challenge you. It's just that in many cases, the readers here might not be very aware of modded lights, dedoming, the risks, and the rewards, so I felt it would be good to comment on this. My own personal experience has been much the same as yours, in that when my lights died, it was due to circuit failure (usually from my own abuse). To date, only one light I had die, was due to the LED, and that was an older light with an XMLT6 led, with really almost no heatsinking.

Looking forward to your beamshots!


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## TEEJ (Apr 11, 2014)

Excellent review SB!

(As always)



Your point about dedomed LED is on point. From what I see, having a lot of dedomed lights, I see no observable degradation of the LED as a result, despite the fact that most of the dedomed lights are also souped up and therefore run hotter to even further improve performance.

If an LED has a factory life of 30,000 hours, and you use it say 2 hours a day, seven days a week (More than most actually get used), that's 14 hours a week, or ~ 2,142 weeks of use from 30,000 hours.

That's roughly 41 YEARS.

If running the LED pedal to the metal, dedomed, cuts the life in HALF (I don't know if it does, I have yet to see one die/dim at all...), that's still ~ 20 YEARS of LED life.

Even halving THAT to ~ 10 years...let's face it, in 10 years, it will be obsolete and outgunned by whatever wonder chip, etc, we have by then.


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## Capolini (Apr 11, 2014)

*SB's complimentary assessments/statements: Some of those "Highlights"! :thumbsup:

*Note that the emitter die centering was perfect on my TK61vn, and was only "good" on my stock TK61 (i.e., not perfectly centered, but not bad). This is again one of the benefits on a custom mod – everything is adjusted for absolute best performance. :thumbsup: 

_____________________________________________________________________________________________________

To look at it another way, that's a 250% increase in throw on my TK61vn, with only a ~65% increase in overall output, from stock. :bow:

_____________________________________________________________________________________________________
the TK61vn is the clear throw king in my testing at the moment. :wave:

_____________________________________________________________________________________________________

How well does this light throw? Well, peak beam intensity is ~3.5 times the stock TK61. oo: That corresponds to ~3 times the stock TN32, and more than twice that of my previous peak throwers, the SBT-70-equipped Olight ST95S-UT and Eagletac MX25L2 Turbo.

_____________________________________________________________________________________________________

The TK61vn is the top-throwing reflector light I've tested to date, bar none. ~600,000cd is an incredibly beam intensity. :bow:

____________________________________________________________________________________________________
Ok, here's the top line: my TK61vn has ~600,000cd by ANSI FL-1 measures, making it the furthest throwing reflector light I've ever tested. 

____________________________________________________________________________________________________

 Thats ALL folks!!!! *  *


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## jmpaul320 (Apr 11, 2014)

thanks SB for the great review

this is a wonderful light  

i have used it for the last few months almost exclusively as my go to thrower

if anyone is worried about the driver - vinh always stands behind his product 100%


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## rdrfronty (Apr 11, 2014)

Nice review on an awesome light. I'm glad to see we are in the same ballpark testing wise. Unfortunately most of us hobbiest cannot afford true integrated sheres, so we do the best with what we can make & afford. And of course we have to create multiplier baselines from lights that are "rated" from the factory. And from my observation, some manufactures tend to test high (eagletac for example) and some tend to test low (zebralight is an example). So there is the fun part of creating the baselines we have to use for our light boxes and meters. If some manufactures are consistantly high and some are consistantly low - exactly which one is correct? We basically have to find the best medium point, just like you did way back when you started this fun.
Anyways, like I said we can only do the best we can. And be consistant with our testing will at a minimum create accurate results relative to other lights we test. 
Again awesome job guy! I always look forward to your reviews and will continue to do so for cool lights in the future.


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## GordoJones88 (Apr 11, 2014)

Speechless.


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## vinhnguyen54 (Apr 11, 2014)

:twothumbs


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## cagenuts (Apr 11, 2014)

Doff question here, are those prices on top of the original cost of the torch or does one purchase a complete modified version from VN?


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## AmperSand (Apr 11, 2014)

Its the total cost for the modified version of the light.


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## cagenuts (Apr 11, 2014)

Thanks &. I've just taken delivery of a stock TK61 which I bought for my fishing trip later this year on Lake Kariba (Zimbabwe) but the throw on this one looks mighty impressive.


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## Ernst from Germany (Apr 12, 2014)

Sehr, sehr strong Beam ,reaching nearly one mile !!!
Ernst


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## selfbuilt (Apr 12, 2014)

InfinitusEquitas said:


> It's just that in many cases, the readers here might not be very aware of modded lights, dedoming, the risks, and the rewards, so I felt it would be good to comment on this.


Yes, I think that's true today. I joined CPF at a time when many here had a hobbyist perspective - a lot of people (myself included) were looking to upgrade and modify our lights, to boost performance. But a whole new breed of good quality (and reasonably inexpensive) lights starting being made by new manufacturers, so the "demographic" around here eventually changed - the majority interest moved to wanting to compare performance of the increasing number of economical commercial lights (which is what I now do almost exclusively). 

As a result, I expect most who come across my reviews today are not familiar with the long tradition of custom building and modding here on the forum - and why I thought some extra comment was needed in the the review. It's also why I'm happy to encourage this side-discussion in the thread, so people can become more familiar with that "other world" of flashlight interest and experience. Hopefully it gives people the idea to check out the custom/modder forum here. :wave:



rdrfronty said:


> Nice review on an awesome light. I'm glad to see we are in the same ballpark testing wise. Unfortunately most of us hobbiest cannot afford true integrated sheres, so we do the best with what we can make & afford. And of course we have to create multiplier baselines from lights that are "rated" from the factory. And from my observation, some manufactures tend to test high (eagletac for example) and some tend to test low (zebralight is an example). So there is the fun part of creating the baselines we have to use for our light boxes and meters. If some manufactures are consistantly high and some are consistantly low - exactly which one is correct? We basically have to find the best medium point, just like you did way back when you started this fun.


Indeed - it is all part of the challenge (and the fun) as a reviewer. This is clearly off-topic, but I certainly have my own personal views as to which manufacturers specs are consistently above or below the trend line.  Fenix has always impressed me with thier remarkable consistency - and close match to my overall best fit line. I note that they claim to use one the industry-standard, flashlight-optimized integrating spheres for all their output measures.

Of course, it is more than just how you measure - it's what you measure, and what you choose to report. Consistency is the one aspect that we really don't have good data on - as we would each need to test a large number of samples. Unfortunately, ANSI FL-1 places no requirement to provide variation data, only the average result (and typically from only 3 samples required). That is likely insufficient to provide a true estimate of the wider "population mean." And when it comes to modded lights, I would expect variation would increase even further - so I hope everyone can appreciate that each of our set of numbers are simply individual data points of one sample in a larger universe of samples.

For that matter, it is only some manufacturers (Fenix among them) that seem to really go for the true average of their test samples in the first place. Others go for the extremes - both high and low. Of course, we can all understand why some may like to report only the high-end ... but there are a couple of well-known manufacturers who seem to prefer to give "low ball" specs (i.e., they are really minimum specs, not average). And that's fine, as long as you are upfront about it - it's actually useful to know the "floor" of minimum expectations (although I suspect the main reason some do it is so they don't need to update their specs/marketing once better output bins start working their way into production). It's an interesting business.


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## hikingman (Apr 12, 2014)

Great review SB as they always are. Just emailed Vinh and ordered one! I agree with TEEJ's assessments (and your's too) about the "life" of these things. I'll want and be in love with newer models way before any old ones die...

Dave


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## gkbain (Apr 12, 2014)

Thanks SB for another educational review. I know very little about flashlights, only been into it for about a year, and none about modded lights. I have read a bit about modding lights but seems like it is for the super flashaholic. This review really sparked my interest and_ Vihn seems to have it all together. I would like to thank __Vinh for providing the light and SB for the review.
_


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## vinhnguyen54 (Apr 12, 2014)

gkbain said:


> Thanks SB for another educational review. I know very little about flashlights, only been into it for about a year, and none about modded lights. I have read a bit about modding lights but seems like it is for the super flashaholic. This review really sparked my interest and_ Vihn seems to have it all together. I would like to thank __Vinh for providing the light and SB for the review.
> _



Thanks!


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## Roger Ranger (Apr 13, 2014)

Wow! Vinh and Selfbuilt. It's like when the guy with the peanut butter ran into the guy with the chocolate! Thank you both.


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## ven (Apr 13, 2014)

Roger Ranger said:


> Wow! Vinh and Selfbuilt. It's like when the guy with the peanut butter ran into the guy with the chocolate! Thank you both.




Thats such a sweet thing to say


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## Jdubs (Apr 13, 2014)

Great review, Selfbuilt! I've been eagerly waiting for this review, and I am looking forward to adding a Vinh-modded light to the stable soon.


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## flashflood (Apr 13, 2014)

Selfbuilt: I am totally stoked that you're branching out into mods! I have one request for mod reviews: it would be great to know what the mod actually is. You covered some of that in this review: for example, dedoming and fine-tuned LED placement. But I'd love to know more about the electronic changes. Is it a completely different driver? Just a resistor change to the standard driver? Photos of the stock and modded drivers, heat sinks, etc would be great. I feel guilty even asking for this, considering how much work you already do on our collective behalf. But, since I know you aim to create the most helpful possible reviews, I humbly offer one member's view of something that would be helpful.


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## GhostReaction (Apr 13, 2014)

Excellent review and looking forward to your distance beamshot :thumbsup:


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## selfbuilt (Apr 13, 2014)

flashflood said:


> But I'd love to know more about the electronic changes. Is it a completely different driver? Just a resistor change to the standard driver? Photos of the stock and modded drivers, heat sinks, etc would be great.


I agree, it would be interesting to see all those things - but I will leave that up to the modders themselves to provide info on. I'm going to stick with comparative performance testing.


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## Mr Floppy (Apr 13, 2014)

flashflood said:


> Is it a completely different driver? Just a resistor change to the standard driver?



It's not a third party driver. http://www.candlepowerforums.com/vb...umen-622-KCD&p=4383782&viewfull=1#post4383782


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## vinhnguyen54 (Apr 13, 2014)

Mr Floppy said:


> It's not a third party driver. http://www.candlepowerforums.com/vb...umen-622-KCD&p=4383782&viewfull=1#post4383782



I use the stock driver hence the factory UI. The orginal transistors could not handle the current so a couple of new transistors were added. These transistors also needed cooling so a piece of thermal pad was also added over them for enhance cooling.


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## GhostReaction (Apr 14, 2014)

Now that would be like exposing a magician secret.
If all the fun are spilled, might as well just wait for stock company to copy Vinh turbo charging ideas. 


flashflood said:


> Photos of the stock and modded drivers, heat sinks, etc would be great.


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## Mr Floppy (Apr 14, 2014)

GhostReaction said:


> If all the fun are spilled, might as well just wait for stock company to copy Vinh turbo charging ideas.



Except Vinh is too nice a guy and pretty much explains most of it when you ask.


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## Vlk (Apr 21, 2014)

selfbuilt said:


> I agree, it would be interesting to see all those things - but I will leave that up to the modders themselves to provide info on. I'm going to stick with comparative performance testing.



This is a hell of a light, a mile throw is incredible. 
Selfbuilt, I think this is a good idea to review well-modified lights. I like custom or at least semi custom things.


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## otisa (Apr 22, 2014)

nice review brother, but Barracuda is the best for me


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## Vlk (Apr 22, 2014)

otisa said:


> nice review brother, but Barracuda is the best for me



They are very different lights, you can't compare them really. The throw of this Fenix is phenomenal.


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## thedoc007 (Apr 22, 2014)

GhostReaction said:


> Now that would be like exposing a magician secret.
> If all the fun are spilled, might as well just wait for stock company to copy Vinh turbo charging ideas.



There is a reason that companies don't boost the current like Vinh, though. They are enthusiast products...if you aren't careful, you can definitely damage them. The extra power does come with extra heat, shorter runtime, and they aren't idiot-proof like most stock lights. So I think Vinh will always have a fan base. And that is a good thing!


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## rickypanecatyl (Apr 27, 2014)

I'm hoping to get a Vinh light soon! 
Re: the life of overdriven, dedomend LED's, I'm a guy that asks a lot of my lights and puts them in some pretty tough situations. Armytechs, Fenix Eagletacs always fail me. My most reliable light to date has been a custom, dedomed over driven light - a Lambda Varapower.
My theory is the TLC, pride of workmanship vastly outweighs cheap, assembly line workmanship that fall within specs.


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## ven (Apr 27, 2014)

I agree ricky,its not just a current bump,extra heat sinking amongst beefing up parts including carrier .Too add the tk61vn is a large light,heat dissipation is on its side and 1700lm is imo not that much for this size of light ,even compared to many standard lights now made by manufacturers.
Also vinh wont push too far,he does mods from what i have and read/seen more on the caution side for longer life .Not just a case of XXXX lumens:thumbsup:

The tk61vn imho is one of the best all round packages,usable flood too which for me is a big bonus.


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## Vlk (Apr 27, 2014)

rickypanecatyl said:


> I'm hoping to get a Vinh light soon!
> Re: the life of overdriven, dedomend LED's, I'm a guy that asks a lot of my lights and puts them in some pretty tough situations. Armytechs, Fenix Eagletacs always fail me. My most reliable light to date has been a custom, dedomed over driven light - a Lambda Varapower.
> My theory is the TLC, pride of workmanship vastly outweighs cheap, assembly line workmanship that fall within specs.



A little off the subject. How has Armytek failed you? Predator, Viking or Barracuda?


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## rickypanecatyl (Apr 28, 2014)

Multiple faulty tailcaps on the Predator. Let's see - trying to bring it back on subject (yet tie it together), one of the things Self built pointed out on his review was Vinh's mods of course void the manufacturer's warranty. 
From what I've seen on Vinh's threads, it seems he really stands behind his products if something does goes wrong - not that I hear about that happening that often. I would point out that voiding both Thrunite's warranty and Armytech's warranty will probably save most people frustration. My experience with both Thrunite and Armytech is you need to call/write multiple times, they'd like you to take the time/money to send in their piece of junk part that failed, they'll then take time to examine to determine if it was your fault or theirs and if you are lucky they will bestow upon you a new piece of junk part that will fail again quickly. They've both replaced parts for me, BUT in all instances I would've been better to just cut my losses and throw it away on failure. Unless you are really, really strapped for cash with lots of free time I don't think many "manufacturer warranties" are worth that much!

I just wanted to point out that what may have appeared as a "con" in the review in reality its probably another pro for the light! I love supporting small business guys that take pride in their work!


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## selfbuilt (Apr 28, 2014)

rickypanecatyl said:


> I just wanted to point out that what may have appeared as a "con" in the review in reality its probably another pro for the light! I love supporting small business guys that take pride in their work!


This is exactly why I do not use the terms "pro" or "con" in my reviews (i.e., you'll see that I refer to that section as "potential issues" in all reviews). I tend to think of it more as risk/reward, which is in the eye of the beholder.


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## InfinitusEquitas (Apr 28, 2014)

rickypanecatyl said:


> My experience with both Thrunite and Armytech is you need to call/write multiple times, they'd like you to take the time/money to send in their piece of junk part that failed, they'll then take time to examine to determine if it was your fault or theirs and if you are lucky they will bestow upon you a new piece of junk part that will fail again quickly. They've both replaced parts for me, BUT in all instances I would've been better to just cut my losses and throw it away on failure. Unless you are really, really strapped for cash with lots of free time I don't think many "manufacturer warranties" are worth that much!



+1

I haven't had any issues with my Armyteks, but have had the same experience with both Thrunite, and Jetbeam. Their "warranties" are not worth the paper they are printed on. Both companies asked that I send the lights back to China for repair. Never mind that the cheapest tracked shipping options are about half the price of most lights.

A lesson hard learned by me, is to only buy flashlights from local/US dealers, never from a seller on ebay/amazon or manufacturer directly.


----------



## Vlk (Apr 28, 2014)

InfinitusEquitas said:


> +1
> 
> I haven't had any issues with my Armyteks, but have had the same experience with both Thrunite, and Jetbeam. Their "warranties" are not worth the paper they are printed on. Both companies asked that I send the lights back to China for repair. Never mind that the cheapest tracked shipping options are about half the price of most lights.
> 
> A lesson hard learned by me, is to only buy flashlights from local/US dealers, never from a seller on ebay/amazon or manufacturer directly.



My experience with Armytek is completely different. I bought both Predator standard and Viking standard directly from them and had to exchange them both. But not because of the tailcap. The service was great. I shipped the lights back to China, emailed Sandra from Armytek the pictures of the postal receipts, and they shipped me new lights registered mail before receiving anything from me. They also paid $15 for shipping each light, which was enough to cover the shipping.
Does Vinh customize Armyteks, by the way? I really like both Predator and Viking, maybe he can make them even better.


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## InfinitusEquitas (Apr 28, 2014)

Vlk said:


> My experience with Armytek is completely different. I bought both Predator standard and Viking standard directly from them and had to exchange them both. But not because of the tailcap. The service was great. I shipped the lights back to China, emailed Sandra from Armytek the pictures of the postal receipts, and they shipped me new lights registered mail before receiving anything from me. They also paid $15 for shipping each light, which was enough to cover the shipping.
> Does Vinh customize Armyteks, by the way? I really like both Predator and Viking, maybe he can make them even better.



I don't have any experience with Armytek support... haven't needed it as of yet. But that was my experience with both Thrunite and Jetbeam. The cheapest tracked option was $40 for international priority. Not really worth it, considering the light was only ~$30.(Archer 1A.)

Vinh does work on them: http://www.candlepowerforums.com/vb...OLD-WTS-APvn-V2-5-(ArmyTek-Predator-Pro-V2-5)


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## Vlk (Apr 28, 2014)

Thank you for the link. Yeah, the first class uninsured shipping without tracking to China was $15.


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## InfinitusEquitas (Apr 28, 2014)

I don't trust shipping without tracking. Even with tracking I had a chinese company claim they never got. Except that it was signed for.


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## Vlk (Apr 28, 2014)

Things happen, sure. But neither US nor Canadian dealers had what I wanted so I had to order directly. Besides, not all my experiences with US dealers were exactly good.
Anyway, this modified Fenix looks great. Problem is that I don't really need it. But if I was going outdoors with big open spaces and weight was not a big issue, yes, I would seriously consider getting it.


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## ven (Apr 28, 2014)

Being honest Vlk I don't really need most of my lights,in fact for years I made do with just a lenser t7 and p3s.....mainly for work.

I live in a built up area so well lit,I do go camping so obv of use there but it's not a weekly thing. I guess I am just addicted to lights,and it's selfbuilts reviews of past(pre member) guided me towards superior lights(thanks to superior reviews) and vinh has increased my interest in lights significantly ........

Better to have and not need than to need and not......


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## InfinitusEquitas (Apr 28, 2014)

Fair to say I passed the "need" stage on lights well over a year ago. No one needs 6-10 flashlights on their nightstand, but they are fun to have.


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## Vlk (Apr 28, 2014)

Right. But I do try to keep it under 10 lights for now.. 
Of which I use two regularly outside and two occasionally inside.
I consider this Fenix a specialty light and I will not have it any time soon. Unless..I can't help it.


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## Patt (May 5, 2014)

Capolini said:


> I am Lucky "13"!!
> 
> Great review!! I also have this torch. It has an awesome display of throw!
> 
> ...



_Capo, you wanna say that... she saw.. with her own eyes....that the beam-throw even about 300yds passed the tower??? OMG....That is just INSANE.... _:wow::rock::rock::rock::twothumbs:twothumbs:twothumbs


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## Patt (May 5, 2014)

ven said:


> Being honest Vlk I don't really need most of my lights,in fact for years I made do with just a lenser t7 and p3s.....mainly for work.
> 
> I live in a built up area so well lit,I do go camping so obv of use there but it's not a weekly thing. I guess I am just addicted to lights,and it's selfbuilts reviews of past(pre member) guided me towards superior lights(thanks to superior reviews) and vinh has increased my interest in lights significantly ........
> 
> Better to have and not need than to need and not......




_Fact is....We're all "FLASHAHOLICS" .... _:twothumbs:twothumbs:twothumbs :rock::rock::rock:


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## Patt (May 5, 2014)

GhostReaction said:


> Excellent review and looking forward to your distance beamshot :thumbsup:



 Yes indeed....me too...  :bow::bow::bow::thumbsup::thumbsup::thumbsup:


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## Patt (May 5, 2014)

My point about "Extreme Modded (or stock) Powerlight"s like the TK61(vn) or the TN32 is....when you handle them well (Don't run them allway's for hours on High or Turbo..) The LED-Emitter will stands for lifetime..(even without dimming) ...
Like mentioned before in this thread...It's true...You'll quicker have..problems with damaged elektrical circuit instead of the LED-emitter... :devil:

I run my lights for maximum 1/2 minut (without pause) on High and/or on Turbo...(that's why my lights "stock or modded" will be running for lifetime without any problems...I hope...)
When you treat your lights allway's like that... you'll gonna have fun for the rest of your life...lol :lolsign:


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## Tmack (May 5, 2014)

And that's all the more reason to have tons of lights. To preserve them. 
(excuse)


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## Capolini (May 5, 2014)

Patt said:


> My point about "Extreme Modded (or stock) Powerlight"s like the TK61(vn) or the TN32 is....when you handle them well (Don't run them allway's for hours on High or Turbo..) The LED-Emitter will stands for lifetime..(even without dimming) ...
> Like mentioned before in this thread...It's true...You'll quicker have..problems with damaged elektrical circuit instead of the LED-emitter... :devil:
> ************************************************************************************************
> *CAPOLINI:*
> ...


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## ven (May 5, 2014)

WOW capolini and patt are really the light of my front room


:laughing:


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## TEEJ (May 5, 2014)

ven said:


> WOW capolini and patt are really the light of my front room
> 
> 
> :laughing:



Jubilant fonts and sizes are their fortes.


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## ven (May 6, 2014)

TEEJ said:


> Jubilant fonts and sizes are their fortes.



:twothumbs:twothumbs:twothumbs:twothumbs:rock::rock::rock::bow::bow::bow::bow::rock::rock::rock::rock::bow::bow::bow::bow::thumbsupparty:

I guess i mean i agree with you

:laughing:


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## thedoc007 (May 6, 2014)

Oh no! The contagion is spreading.


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## ven (May 6, 2014)

thedoc007 said:


> Oh no! The contagion is spreading.




Dont worry,i just suffered from pattolini syndrome for a minute:nana:

:laughing:


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## shrike2222 (May 7, 2014)

Thanks for great review.


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## Bullyson (May 14, 2014)

poop has the snow not melted at the North Pole yet?


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## Capolini (May 14, 2014)

Bullyson said:


> poop has the snow not melted at the North Pole yet?


 

I am sure it has. Please keep in mind that SB is a busy man and he stated on another thread that he would be out of town until early May,,he will get to it.* *


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## selfbuilt (May 14, 2014)

Capolini said:


> I am sure it has. Please keep in mind that SB is a busy man and he stated on another thread that he would be out of town until early May,,he will get to it.


Indeed I am. Mainly waiting for a decent evening that isn't raining or windy (as it has been for the last week). The weekend forecast is looking better. Most trees have buds or blossoms on them now, so there will finally be something more than twigs to look at.


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## ven (May 14, 2014)

Great news selfbuilt,be excellent for colours too:twothumbs thanks again for your time and effort that benefits us all so much


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## selfbuilt (May 17, 2014)

Weather conditions have finally improved enough to start taking outdoor beamshots around here. To start, here is a comparison of the TK61vn to the stock form and the Thrunite TN32. I plan to add additional comparisons over the comping weeks, as I bring out some new lights to test.

As always, these are done in the style of my earlier 100-yard round-up review. Please see that thread for a discussion of the topography (i.e. the road dips in the distance, to better show you the corona in the mid-ground). 












As you can see, the V54 mod and dedoming hugely increases center-beam throw. oo: You can see why this build was a good choice for this mod, as even the stock TK61 has a very focused beam. As you can also tell from above, the stock TN32 has greater output than the stock TK61 (this is another selling point in favor of the V54 mod, as overall output similarly increases).

I will be updating this review with additional beamshots in a few weeks, comparing the TK61vn to some of the higher output lights out there. Just waiting on my MM15vn samples to arrive, so I can head out with the TK75, Supbeam X60, etc. all at once


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## ven (May 17, 2014)

Awesome selfbuilt,very impressive and great pics,thank you,look forward to more comparisons in the future:thumbsup:


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## kj2 (May 17, 2014)

selfbuilt said:


>


Damn!


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## Capolini (May 17, 2014)

*AWESOME BEAM SHOTS SELFBUILT!!* :thumbsup: :twothumbs

The pictures certainly tell the story!! The beam intensity of the TK61vn is so much more intense than the other lights. I never saw such domination when comparing lights! No doubt because it is a modded masterpiece! 

**


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## selfbuilt (May 17, 2014)

Capolini said:


> The pictures certainly tell the story!! The beam intensity of the TK61vn is so much more intense than the other lights. I never saw such domination when comparing lights! No doubt because it is a modded masterpiece!


Yes, this is the first light that clearly over-saturates the hotspot at my standardized camera settings for this distance. Very impressive. I may need to come up with new settings for Vinh's lights, if this continues.


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## caddylover (May 17, 2014)

I should be getting mine today!  Nice shots!!


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## GhostReaction (May 17, 2014)

The lux benchmark has been set. King thrower in Reflector / 4x 18650 class.
This is one insane reflector light. 

Eagerly waiting for reflector / single 18650 throw king.


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## Capolini (May 17, 2014)

Before I got the TK61vn :thumbsup: I was deciding whether to get the TK61 or the TN32,,stock versions. 

I decided on the TN32. For me, your beam shots help justify my decision between those two! Not only by the numbers, it is also visually evident that the TN32 has more output and beam intensity than the TK61.

Then, you look at the TK61vn compared to those Two[TN32/TK61] stock lights and you can see why we buy, enjoy and are in awe of *Vinhs CREATIONS!! :twothumbs

*This is coming from a guy that use to be against modded lights[pros/cons] until I turned the corner and found *"FLASHAHOLIC EUPHORIA!!!

*


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## Patt (May 18, 2014)

_
Very well done Selfbuilt....these pics are just awesome...(waited longtime for a comparison between these awesome lights...thx bro...)
Yeah me too..I look out for more comparisons made by U...lol _:lolsign:
_​Patt_


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## Patt (May 18, 2014)

_ 
Oh boy...just insane...I gotta have my "TK61vn" as soon as possible... _ _ _


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## panag (May 18, 2014)

great review sb:twothumbs


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## TEEJ (May 19, 2014)

SB- Excellent Job!


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## click here (May 19, 2014)

Does anyone know if a diffuser exists that could fit this head? I'm really considering getting it but would like to have a diffuser cap for flood when I need it.


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## TEEJ (May 19, 2014)

click here said:


> Does anyone know if a diffuser exists that could fit this head? I'm really considering getting it but would like to have a diffuser cap for flood when I need it.



It makes more sense to simply carry a small floody pocket light for flood, than to carry a large light optimized for throw and then a cap for it to undo the throw. 

If you must, a simple sheet of diffuser film would work.


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## Tmack (May 19, 2014)

Those hydration molle packs hold a tk61vn in the main compartment and a mm15vn in the front. Perfection


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## selfbuilt (May 20, 2014)

click here said:


> Does anyone know if a diffuser exists that could fit this head? I'm really considering getting it but would like to have a diffuser cap for flood when I need it.


Well, the original Olight SR90/SR92 head was 97mm, which is just 1mm wider than the TK61. I believe Olight had released a diffuser for those models, but it may be hard to find now.


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## NCRick (May 21, 2014)

This question is probably best directed to Vihn himself, but I was curious if he only mods lights he purchases himself and then sells for a modest markup to cover his time, effort and cost of parts, or does he mod member owned lights as well?

Reason for asking here: I had been looking at the TK75 but found that the TK61 may be a better fit for what I am looking to get from this model. I'm not sure yet if I need to go all the way and get a 600K+ cd light sabre without testing it in stock form. If I was to purchase a stock TK61, would a VN mod still be an option? I of course would expect that shipping it to him would be my responsibility. Beyond that, what would the cost be for an upgrade similar to this (if an option)? I'm sure there would be an additional charge to cover return shipping as well (to Charlotte, NC in my case).

Thanks selfbuilt for another great review and well done to Vihn for an amazing upgrade. Outstanding work! :twothumbs


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## vinhnguyen54 (May 21, 2014)

NCRick said:


> This question is probably best directed to Vihn himself, but I was curious if he only mods lights he purchases himself and then sells for a modest markup to cover his time, effort and cost of parts, or does he mod member owned lights as well?
> 
> Reason for asking here: I had been looking at the TK75 but found that the TK61 may be a better fit for what I am looking to get from this model. I'm not sure yet if I need to go all the way and get a 600K+ cd light sabre without testing it in stock form. If I was to purchase a stock TK61, would a VN mod still be an option? I of course would expect that shipping it to him would be my responsibility. Beyond that, what would the cost be for an upgrade similar to this (if an option)? I'm sure there would be an additional charge to cover return shipping as well (to Charlotte, NC in my case).
> 
> Thanks selfbuilt for another great review and well done to Vihn for an amazing upgrade. Outstanding work! :twothumbs



Check out my subforum here: http://www.candlepowerforums.com/vb/forumdisplay.php?140-Vinhnguyen54

Send me mod request here: [email protected]


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## thedoc007 (May 21, 2014)

NCRick said:


> If I was to purchase a stock TK61, would a VN mod still be an option? I of course would expect that shipping it to him would be my responsibility. Beyond that, what would the cost be for an upgrade similar to this (if an option)? I'm sure there would be an additional charge to cover return shipping as well...



Generally it is much cheaper to buy directly from Vinh...he buys in bulk, and gets good discounts. It is substantially more expensive to get your own, and then later send it in (shipping is included in any quote he gives you). But if money is tight now, you could indeed buy a stock version, and then send it to Vinh later. Just realize that it will end up costing you more.


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## NCRick (May 22, 2014)

Thank you both for the quick replies and the helpful information. I figured it was cheapest to buy direct but due to my current circumstances I'm not able to go that high right now (not that it isn't well worth it for the incredible upgrade). I just ordered a stock TK61 off Amazon.com for $129.99 and I get free shipping for being a Prime member. I figured that was a pretty good price and leaves room for mod fees later on.

Vinh - I will be sure to check out your link. If I have any questions or want a serious quote then I will send an email to discuss arrangements. Since I do have some money coming for a couple settlements and reimbursements maybe I can stick with the stock TK61 and try out one of your TK75vn models once I have a little better budget.

:thanks:


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## Patt (May 25, 2014)

_Yess..ordered my TK61vn ... _:devil: :rock:  _Can't wait to test that awesome thing...__ _


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## radu1976 (May 27, 2014)

Selfbuilt. could you please clarify something ?
According to your chart the TK61vn has 1,650 lumens on TURBO and 770 lumens on high. So HIGH would be about 47% of the TURBO so the lux on HIGH are about *280,000*
According to the graphic though, HIGH seems to be about 60% of the TURBO - 210 vs 350 - so the throw would be *360,000 lux*.
I am considering buying this light but I don't plan to use it on TURBO but on HIGH - much longer runtime and efficiency and safety reasons also -
What throw should I expect for when running on HIGH ?
Thank you !


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## TEEJ (May 27, 2014)

radu1976 said:


> Selfbuilt. could you please clarify something ?
> 
> According to your chart the TK61vn has 1,650 lumens on TURBO and 770 lumens on high. So HIGH would be about 47% of the TURBO so the lux on HIGH are about *280,000*
> 
> ...




I don't think the two charts are related in that way to each OTHER though....they are relative scales, for the indicated set of parameters.


A point to consider...the throw was measured, your numbers are based upon an interpretation of a chart. Typically, empirical date is superior to interpreted data.


The bottom line, for you, should be the distance you need to see what at. 

IE: What range did you want to be able to resolve what at? ( A guy in white requires very little lux compared to a guy in dark clothing, etc)



Give the range and target example that would illustrate what you need.


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## selfbuilt (May 27, 2014)

radu1976 said:


> According to your chart the TK61vn has 1,650 lumens on TURBO and 770 lumens on high. So HIGH would be about 47% of the TURBO so the lux on HIGH are about *280,000*
> According to the graphic though, HIGH seems to be about 60% of the TURBO - 210 vs 350 - so the throw would be *360,000 lux*.


As TEEJ pointed out, actual measures are better than inferred estimates. But generally, the percent lumen change is a pretty good indicator of the percent beam distance change.

The reason the graphs look different is the relative scale of my lightbox is not linear to lumen output. The lumen estimates in the table are relatively consistent - stick with those. If you follow the link in my methodology section, you will see some formulas to help you convert the relative output values of the lightbox.


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## Vlk (Jun 26, 2014)

Selfbuilt,
Is it safe to use unprotected Panasonic 18650 in it? What about IMR and Samsung INR ?


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## vinhnguyen54 (Jun 26, 2014)

Vlk said:


> Selfbuilt,
> Is it safe to use unprotected Panasonic 18650 in it? What about IMR and Samsung INR ?



All 18650 are safe.


----------



## Vlk (Jun 26, 2014)

vinhnguyen54 said:


> All 18650 are safe.



Thank you, Vinh. That's important to know. Personally, I prefer to use Panasonic NCR18650A 3100 mAh industrial whenever possible, and SureFire 123A. I just have more faith in them.


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## selfbuilt (Jun 26, 2014)

Vlk said:


> Thank you, Vinh. That's important to know. Personally, I prefer to use Panasonic NCR18650A 3100 mAh industrial whenever possible, and SureFire 123A. I just have more faith in them.


Yes, unprotected cells are safe in this light - but only because the circuit steps down, warning you when battery voltage is low.

As a general rule, I don't see an advantage to using unprotected ICR cells in any light (other than maybe cost). You are always better off using protected versions, when available. Of course, that is different for high drain lights that need IMR/INR (but this isn't one of those).


----------



## RemcoM (Jun 26, 2014)

selfbuilt said:


> These are good points - as is the issue of variability of manufacturer warranty support. On that earlier point, my goal was simply to point out that manufacturer warranties are null and void by modding - if that matters to the end user. As always, I leave it up to the consumer to decide what features of a light matter to them (which is why I generally don't "recommend" lights here, or provide a value ranking scheme).
> 
> As for the latter point, in the interest of being balanced I've amended my two comments in the review as follows: _(italics showing the addition)_
> 
> ...



Hi Selfbuilt,

1 What do you mean, with anti glare coating on the TK61? The light comming from the TK61 is blinding off course at high settings, so it have alot of blinding glare.

Please explain.

2 For how long can the Led produce 170000 cd on the stock version? Before the led gets used and old?

Some years, with daily using, for some short/long moments on turbo?

Remco


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## Vlk (Jun 26, 2014)

selfbuilt said:


> Yes, unprotected cells are safe in this light - but only because the circuit steps down, warning you when battery voltage is low.
> 
> As a general rule, I don't see an advantage to using unprotected ICR cells in any light (other than maybe cost). You are always better off using protected versions, when available. Of course, that is different for high drain lights that need IMR/INR (but this isn't one of those).




Thank you, Selfbuilt.
Besides cost those and other Panasonic give you a better runtimes and they are fully made in Japan not assembled in China. One of AW 3100 protected failed me, by the way, after a short time - the wrapper started coming off. And I didn't do anything wrong, just was using it in my Armytek Viking which is not really hard on batteries.


----------



## selfbuilt (Jun 26, 2014)

Remco,

Anti glare refers to the coating on the lens. Like glasses, higher end ones come with an anti glare coating, cheaper ones don't. The TK61 has one. It is believed to help with direct transmission, but I have no data on the subject, and can't comment further.

As for the LED, I again have no data on rate of decay. I simply point out the obvious that heavily driven and dedomed emitters may have a shorter lifespan.



Vlk said:


> Thank you, Selfbuilt.
> Besides cost those and other Panasonic give you a better runtimes and they are fully made in Japan not assembled in China. One of AW 3100 protected failed me, by the way, after a short time - the wrapper started coming off. And I didn't do anything wrong, just was using it in my Armytek Viking which is not really hard on batteries.


Hmm, well, it is the same core made in Japan cell regardless of where the protection circuit comes from. I would be surprised if there were so much overhead from the circuit to reduce runtimes very significantly, but others here would know more if they have tested it (like HKJ).

I agree that a damaged wrapper is a real bummer on an otherwise new cell. You can replace it, but I agree it is an extra annoyance.


----------



## Vlk (Jun 26, 2014)

selfbuilt said:


> Remco,
> 
> Anti glare refers to the coating on the lens. Like glasses, higher end ones come with an anti glare coating, cheaper ones don't. The TK61 has one. It is believed to help with direct transmission, but I have no data on the subject, and can't comment further.
> 
> ...



Viking standard cool white gave me 10 minutes more on max with Panasonic NCR18650A 3100 than AW 3100 protected that uses the same cell. I tested them from max to the lowest setting not to flickering. Now, for most of us under most circumstances 10 minutes difference is not much. But I do tend to view flashlights as emergency and survival tools, so additional ten minutes of light is important to me.


----------



## thedoc007 (Jun 26, 2014)

Vlk said:


> Viking standard cool white gave me 10 minutes more on max with Panasonic NCR18650A 3100 than AW 3100 protected that uses the same cell. I tested them from max to the lowest setting not to flickering. Now, for most of us under most circumstances 10 minutes difference is not much. But I do tend to view flashlights as emergency and survival tools, so additional ten minutes of light is important to me.



Well, that doesn't really say anything about the general quality of one brand versus the other. Are the cells the same age? Do they have the same number of cycles? Has one been stored in a different environment? HKJ has found fairly consistent performance across a variety of brands. The cell inside is what mostly determines the performance...the protection circuit will likely influence the amount of current it can deliver, but it shouldn't influence the runtime much.


----------



## Vlk (Jun 26, 2014)

thedoc007 said:


> Well, that doesn't really say anything about the general quality of one brand versus the other. Are the cells the same age? Do they have the same number of cycles? Has one been stored in a different environment? HKJ has found fairly consistent performance across a variety of brands. The cell inside is what mostly determines the performance...the protection circuit will likely influence the amount of current it can deliver, but it shouldn't influence the runtime much.



They were bought new at the same time from reliable sources, tested after a few cycles on each. I have four unprotected Panasonics and couple of AWs. All Panasonics give longer runtimes on Max and High, about the same on Med and Low. Same results with Armytek Predator standard. Convincing enough for me, not to mention that they are half the price. I might try Redilast and Orbtronics later, maybe.
If I later get this light from Vinh, I will push it hard. Not ten minutes on Max, thirty minutes at least. If it gets too hot to hold -I'll just use gloves. High performance light should be able to hold its own, within reason.


----------



## thedoc007 (Jun 26, 2014)

Vlk said:


> They were bought new at the same time from reliable sources, tested after a few cycles on each. I have four unprotected Panasonics and couple of AWs. All Panasonics give longer runtimes on Max and High, about the same on Med and Low. Same results with Armytek Predator standard. Convincing enough for me, not to mention that they are half the price. I might try Redilast and Orbtronics later, maybe.
> If I later get this light from Vinh, I will push it hard. Not ten minutes on Max, thirty minutes at least. If it gets too hot to hold -I'll just use gloves. High performance light should be able to hold its own, within reason.



Ok, good to know. I've avoided AW anyway due to the price - there are LOTS of choices for quality Panasonic cells at this time. No reason to pay $20 per cell. I am surprised by those findings, but if it is consistent across several cells, I don't doubt they are under-performing for some reason.

I'd be careful running the TK61vn continuously on turbo, in a warm to hot environment, especially without at least some air moving over it...wouldn't be a problem walking, most likely, but if you want to tailstand it, you may well burn out the driver. Manufacturers limit the current on stock light for a reason...but good luck!


----------



## Vlk (Jun 26, 2014)

thedoc007 said:


> Ok, good to know. I've avoided AW anyway due to the price - there are LOTS of choices for quality Panasonic cells at this time. No reason to pay $20 per cell. I am surprised by those findings, but if it is consistent across several cells, I don't doubt they are under-performing for some reason.
> 
> I'd be careful running the TK61vn continuously on turbo, in a warm to hot environment, especially without at least some air moving over it...wouldn't be a problem walking, most likely, but if you want to tailstand it, you may well burn out the driver. Manufacturers limit the current on stock light for a reason...but good luck!




Yes, of course I meant while walking, riding a boat etc. And I wouldn't push it hard intentionally, well, maybe once just to make sure it works. But again, this should be a hell of a light for great outdoors if the weight is not a problem. A mile of light from a not so big flashlight...


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## Vlk (Jul 8, 2014)

selfbuilt said:


> Yes, unprotected cells are safe in this light - but only because the circuit steps down, warning you when battery voltage is low.
> 
> As a general rule, I don't see an advantage to using unprotected ICR cells in any light (other than maybe cost). You are always better off using protected versions, when available. Of course, that is different for high drain lights that need IMR/INR (but this isn't one of those).



There is another reason to use unprotected ICR and IMR batteries whenever safe. It appears that protected batteries are more fragile, that's their protective circuit is fragile, and as a consequence of it the battery may fail under mechanical stress, even if the light is dropped on concrete floor from only one meter height. At least that's what people on HDS forum say.


----------



## TEEJ (Jul 9, 2014)

Vlk said:


> There is another reason to use unprotected ICR and IMR batteries whenever safe. It appears that protected batteries are more fragile, that's their protective circuit is fragile, and as a consequence of it the battery may fail under mechanical stress, even if the light is dropped on concrete floor from only one meter height. At least that's what people on HDS forum say.



It depends on the light they are in and the impact itself.

I've never had a protected cell knocked out by a fall....and some of the Fallen lights flew 30' or more, let alone a meter, etc.

It CAN happen, but it might be some cell protection parts are more fragile, and some are tougher. ..and some lights might cushion cell impacts better than others, etc.


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## Vlk (Jul 9, 2014)

TEEJ said:


> It depends on the light they are in and the impact itself.
> 
> I've never had a protected cell knocked out by a fall....and some of the Fallen lights flew 30' or more, let alone a meter, etc.
> 
> It CAN happen, but it might be some cell protection parts are more fragile, and some are tougher. ..and some lights might cushion cell impacts better than others, etc.




Yeah, it's always a game of chance when the lights fly and hit something. 
I wonder, how would this particular Fenix light and batteries in it withstand serious fall?
Maybe Selfbuilt or Vinh would like to experiment.


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## selfbuilt (Jul 9, 2014)

Vlk said:


> I wonder, how would this particular Fenix light and batteries in it withstand serious fall?
> Maybe Selfbuilt or Vinh would like to experiment.


I expect it would hold up well, given how sturdy the carrier is. I would consider the risk of protected cell failure due to impact to be exceeding low (compared to the common risk associated with potential over-discharged or mismatch-charged unprotected cells in multi-cell lights).


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## Vlk (Jul 9, 2014)

selfbuilt said:


> I expect it would hold up well, given how sturdy the carrier is. I would consider the risk of protected cell failure due to impact to be exceeding low (compared to the common risk associated with potential over-discharged or mismatch-charged unprotected cells in multi-cell lights).



I see. You advocate using protected cells in any multi-cell light because it is the safest approach.
But somehow in the case of this particular light you did not convince me. I would use trusty Panasonic NCR18650A without hesitation.
Thank you for the participation in the discussion.


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## Vlk (Jul 9, 2014)

A little off the subject. I always thought that it is the job of the device to protect the user, itself and the batteries that power it. Personally, I would not use a flashlight that requires I use protected batteries.
I think, they use 2000 or so Panasonic batteries in Tesla electric car, maybe custom, I don't know.


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## selfbuilt (Jul 10, 2014)

Vlk said:


> A little off the subject. I always thought that it is the job of the device to protect the user, itself and the batteries that power it. Personally, I would not use a flashlight that requires I use protected batteries.
> I think, they use 2000 or so Panasonic batteries in Tesla electric car, maybe custom, I don't know.


Battery packs have a circuit that regulate charging and monitor performance, hence why individually-protected cells are not required inside the pack. The device can only do so much to protect you if you are using your own cells, which gets back to why user-replaceable cells should ideally have their own protection circuits whenever possible. The main risk with Li-ions comes not in use, but during charging (i.e., a sustained discharge beyond the normal low-voltage cut-off level of protected cells will physically damage Li-ions, meaning they should never be placed back on a charger). 

This is definitely off-topic now, so I would request any further discussion take place in the batteries forum.


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## netvlada (Jul 30, 2014)

Nice review.

Do you plan to upgrade it for New V2,version???


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## selfbuilt (Jul 30, 2014)

netvlada said:


> Do you plan to upgrade it for New V2,version???


No, I think I'll stick with the original driver/interface. The new V2 should only have a modest increase in output (and thus throw).

I am working on a couple of other lights from Vinh though ... stay tuned.


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## jmpaul320 (Jul 31, 2014)

netvlada said:


> Nice review.
> 
> Do you plan to upgrade it for New V2,version???


Fwiw you can check out the link in my Sig. I measured lumens and lux on v1 and the v2 prototype


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## RemcoM (Aug 8, 2014)

Hi Selfbuilt,

Is the light comming out of my Stock Fenix TK61 blindingly bright for other people, at close, to moderate distance away from the light?

When they staring into it?

At low 6700 cd, at medium, 29000 cd, at high 70000 cd, and what about the blinding risk, at turbo, at 170000 cd?

Can the TK61 be annoyingly bright for other people?


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## selfbuilt (Aug 8, 2014)

RemcoM said:


> Can the TK61 be annoyingly bright for other people?


Yes, I would say so. Any throwy light is going to be blinding if stared directly into. You would want to shine away from them (i.e., illuminated only in the spill, not the hotspot). A diffuser cover is useful for any light, if you want to avoid blinding people.


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## netvlada (Aug 9, 2014)

Selfbuilt

How you can compare TK61vn vs DEFT-X.I mean thet Dext-x have zero spill and you can not see nothing around you and in near front.For example if you are on open road at max throw can you see road around you where to walk.


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## selfbuilt (Aug 9, 2014)

Sorry, don't have the DEFT to compare.


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## TEEJ (Aug 9, 2014)

netvlada said:


> Selfbuilt
> 
> How you can compare TK61vn vs DEFT-X.I mean thet Dext-x have zero spill and you can not see nothing around you and in near front.For example if you are on open road at max throw can you see road around you where to walk.



You are comparing a reflector based beam to a wavien light collar aspherical beam...and they are completely different.

A search light is used to see things a long way off, and is not designed to light a path right in front of you....as there would be a very bright hot spot that kills your night vision and hinders proximal peripheral vision.

Having a DeftX, I can say that the best way to describe the beam is to imagine you were holding a slide projector, and, aiming a picture of the LED on distant targets to light them up.

For the reflector based light, the beam is more conventional, in that there is some spill, a corona and a hot spot...but, Vinh's thrower is also going to not be the best tool for the job if path lighting is the objective.

Both lights have a VERY concentrated central beam....and turning it to a lower mode just gives a teeny spot of concentrated light....so seeing what's out there with either is very much like looking through a paper towel tube sort of view.

For path lighting, a second light with a floody beam works MUCH better.


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## netvlada (Aug 9, 2014)

Yes,correct.
Because of thet ,there is Deft-Rev.
If you consider price vs spec which is better option,Tk61vn or Deft-X.
My dream is to have two Deft-x heads and just to swap it for throw or floody beam[emoji3]


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## TEEJ (Aug 9, 2014)

netvlada said:


> Yes,correct.
> Because of thet ,there is Deft-Rev.
> If you consider price vs spec which is better option,Tk61vn or Deft-X.
> My dream is to have two Deft-x heads and just to swap it for throw or floody beam[emoji3]



It depends on your use.

The DeftX out throws the TK61vn...so if say ultimate range was your primary criteria, the DeftX wins. If range per dollar was the contest, the TK61vn wins.

If we round the throws that each might give you, you are talking about ~ 740 k cd vs 1.1 million cd

That looks like a lot, so, in the field, say using range to 1 lux, its ~ 860 meters vs ~ 1,049 meters.

If using as a search/disaster response light, say to search for survivors, etc, and you use 15 lux, its more like ~ 271 meters vs ~ 222 meters.

That CAN make a difference between resolving a leg from a branch at that kind or range in a search, and if you're the victim being looked FOR, YOU'D like the searcher to have the brighter light if you're ~ 250 meters away and bleeding out.

If I am equipping guys for a search though, and I can get THREE 740 k cd lights, or ONE 1.1 M cd light, I would feel that the three 740's could search a larger area more quickly overall, etc.

If I have to patrol a 500 meter wide river or flood zone, etc, and am cruising down the middle to search both banks at the same time, I'd better have the DeftX (Or other search light with that magnitude cd) to be able to hit both banks with 15+ lux from the same point.

So, sometimes the task dictates the best tool for it.


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## mks195 (Sep 25, 2014)

Thank you SelfBuilt for all you do for the flashlight hobbyist > enthusiast > "flashaholic" community! Just sent a modest donation to your battery fund. 
Please continue your Great Work! :twothumbs


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## RemcoM (Sep 16, 2015)

Hi Selfbuilt,

Can the TK61vn, reach visibly, or clearly a treeline, at 1000 meters-1 kilometre,

i want order this light also, so i want know.

Thank you.


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## selfbuilt (Sep 19, 2015)

RemcoM said:


> Can the TK61vn, reach visibly, or clearly a treeline, at 1000 meters-1 kilometre,


There is a new version of this light offered by Vinh now, with greater throw. It should indeed reach 1 km, but not sure how "visibly" or "clearly" that would be to the naked eye.


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## Peter111 (Feb 25, 2016)

vinhnguyen54 said:


> :twothumbs




Hello Vin,

Where can I purchase your Fenix TK61vn flashlight and how much would that cost me including shipping to Australia please?

Thank you Vin.

Kind regards,

Peter 

NSW, Australia


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## KeepingItLight (Feb 26, 2016)

:welcome: Hi, Peter!

Vinh has his own forum at CPF. You will find it here. You might try posting a message there. Better still, why not send him a private message (PM)? His user name is Vinhnguyen54.

Another place to purchase his flashlights is his new web site: skylumen.com

Hope this helps.


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## Alex1234 (Feb 26, 2016)

KeepingItLight said:


> :welcome: Hi, Peter!
> 
> Vinh has his own forum at CPF. You will find it here. You might try posting a message there. Better still, why not send him a private message (PM)? His user name is Vinhnguyen54.
> 
> ...




Vinh disabled his PM feature on this forum. He wants all questions and orders emailed to him at [email protected]


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## Capolini (Apr 30, 2016)

deleted


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