# Fenix LD60 (3xXM-L2 - 3x18650, 6xCR123A) review: RUNTIMES, BEAMSHOTS, SCOPE + more!



## selfbuilt (Oct 16, 2014)

I've reviewed a large number of 3xXM-L2 lights over the last few years – and the LD60 is the second one I've tested from Fenix, after the TK75. 

There are some noticeable differences between the LD60 and other recent high-output lights from Fenix. Most immediately obvious is the single switch for off/on and mode control now, and the lack of a battery carrier. Let's see how the LD60 compares to other lights in this class … :wave:

*Manufacturer's Specifications:*
_Note: as always, these are only what the manufacturer reports. To see my actual testing results, scroll down the review._


LED: Utilizes three Cree XM-L2 (U2) LEDs 
Powered by three 18650 rechargeable Li-ion batteries or six 3V CR123ALithium batteries
Output mode / Runtime: Turbo: 2800 lumens / 1h 30min, High: 1500 lumens / 3h, Mid: 500 lumens / 9h, Low: 160 lumens / 29h, Eco: 30 lumens / 150h
Beam Intensity: 53,000cd
Beam Distance: 460m
IPX-8, underwater 2m
Impact resistance 1m
Dimensions and Weight: Length: 6.10" / 155mm, Body Diameter: 1.81" / 46mm, Head Diameter: 2.48" / 63mm
Weight:12.8oz / 364gm (excluding batteries)
Triple LEDs with separate circuit design
Intuitive one-button operation
Intelligent thermal control to protect the flashlight against over heating
Camera tripod mountable
Digitally regulated output - maintains constant brightness
Reverse polarity protection guards against improper battery installation
Over-heat protection to avoid high-temperature of the surface
Made of durable aircraft-grade alluminum
Premium Type III hard-anodized anti-abrasive finish
Toughened ultra-clear glass lens with anti-reflective coating and quality PC lens
MSRP: ~$150






















Packaging is fairly standard for Fenix. The cardboard box has key performance and specifications printed right on the outside. Inside, in a thin plastic tray, you will find the light, extra o-rings, basic wrist strap, basic holster (with closing flap), manual, warranty card and product insert. 













From left to right: Keeppower Protected 3100mAh 18650; Fenix LD60; Sunwayman T60CS; Nitecore TM15; Olight SR52; REV Captor. 

All dimensions are directly measured, and given with no batteries installed:

*Fenix LD60*: Weight: 334.6g (~476g with 3x18650), Length: 154.9mm, Width (bezel): 63.1mm
*Fenix TK75*: Weight: 516.0g (~704g with 4x18650), Length: 184mm, Width (bezel): 87.5mm
*Foursevens MMU-X3*: Weight: 172.0g (264.2g with 26650), Length: 135.8mm, Width (bezel): 46.0mm
*L3 Illumination (Supbeam) X40*: Weight: 517.2g (~658g with 3x18650), Length: 182mm, Width (bezel): 68.0mm
*Nitecore TM15:* Weight: 450.6g (~638g with 4x18650). Length: 158mm, Width (bezel): 59.5mm
*Nitecore TM11*: Weight: 342.6g (~526g with 8xCR123A), Length 135.3mm, Width (bezel): 59.5mm 
*REV Captor*: Weight: 498.3g (~640g with 3x18650), Length: 182mm, Width (bezel): 68.0mm
*Sunwayman T60CS:* Weight: 338.9g (~480g with 3x18650), Length: 145.0mm, Width (bezel): 60.0mm
*Thrunite TN30*: Weight: 468.2g (~623g with 3x18650), Length: 179mm, Width (bezel): 64.3mm, Width (tailcap): 49.0mm 


























The LD60 has a distinctive shape for Fenix, and is fairly compact for this 3xXM-L2/3x18650 class. Anodizing is a flat black, and is in excellent shape on my sample. Body labels are minimal, and clear. 

Unlike the recent TK-series lights, there is actual knurling on the body (of mild aggressiveness). Combined with the ridge detail in the head, and the grippy button cover, I find overall grip to be good.

Tailcap hreads are square-cut, and anodized for lock-out. :thumbsup:. 

The light can tailstand, and there are raised cut-outs for attachment of the wrist lanyard.

The LD60 uses a novel (for Fenix) single electronic switch to control on/off and mode switching. Switch feel is about typical, and there is a definite "click" when making full contact. Scroll down for a discussion of the user interface.

There is a tripod mount attachment on the head of the light (on the other side, across from the switch).

Unlike recent TK-series lights, there is no battery carrier on the LD60 – instead, batteries are held inside the handle/body of the light. There are springs at both ends, so flat-top batteries will work fine. All my various size cells worked without issue.

Circuit design is also novel, as the light can run on 1x, 2x or 3x18650 (with a corresponding number of emitters activated). This implies a parallel arrangement of for the cells, and independent circuit control for each emitter. Scroll down to my testing results for more info.


















The LD60's reflector has relatively deep emitter wells, overlapping a significant amount in the middle. Although there is no such thing as a "typical" tri-head structure, this seems pretty close to what I commonly observe. The reflector appears to be in excellent shape on my sample, very smooth. Centering of the emitters was a bit variable though, with all of them being at least slightly off-center (although this didn't appreciably affect the beam). Scroll down for beamshots.

*User Interface*

Turn the light Off/On by a press-and-hold of the electronic switch for at least ~0.5 secs.

From On, change output modes by clicking (i.e., rapid press and release) the switch. The light will cycle between constant output modes in the following order: Eco > Lo > Med > Hi > Turbo, in repeating order. Note the manual incorrectly lists the reverse order. 

Light has mode memory, and will retain the last constant output used when turning Off and On.

There is a "hidden" strobe accessible from either On or Off by pressing and holding the switch for longer than it takes to turn the light On or Off. It takes ~1.2 secs of sustained press to activate the strobe mode. This means you will pass through the previously memorized On mode (if activating from Off), or pass through Off (if activating from On), en route to Strobe. Note as well that the Strobe is constant output if activated from On, and momentary only if activated from Off.

*Video*: 

For more information on the light, including the build and user interface, please see my video overview:



_*Note:* there is prominent signal in the beam on the non-max output modes, which the video camera is heavily accentuating (i.e., showing as an interference pattern). It is not as noticeable in real life as the video appears. See my Oscilloscope section for more details._

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.

*Oscilloscope Traces*

There have been concerns raised here that Fenix is using Pulse Width Modulation (PWM) on the LD60. The _only_ way to clarify this question is with proper oscilloscope traces. :wave:

Below is a comparison of each of the five output modes on my sample – all shown on the same time and amplitude scale (i.e., to allow direct relative comparisons). 

LD60 Eco mode:





LD60 Lo mode:





LD60 Med mode:





LD60 Hi mode:





LD60 Turbo mode:





I will explain what is going on in more detail below, but the take-home message is that the *LD60 is NOT using PWM for its lower modes*, and appears to be current-controlled as always. _However, it does have a reoccurring signal present in all non-Turbo modes that may be perceptible as "flicker" for ultra-sensitive individuals._ 

Check out this post from my LD12 review (which had a similar signal pattern on some levels) for a detailed discussion of what PWM is and isn't - and what to look for in oscilloscope traces. But to summarize, PWM is a means of lowering perceived output for sub-max modes. It has a constant frequency and amplitude across all levels, with a square wave pattern, and is only variable for pulse width. In contrast, my LD60's reoccurring signal has variable frequency and amplitude, which moves to a full sinusoidal wave pattern by the Hi mode. Moreover, the duration of the signal width across levels does not correlate with perceived output. 

While this LD60 pattern is definitely not PWM, the visual oscillations are still a potential problem for perceptual flicker – _although far less so than PWM proper_. To understand that comment, let me break down the types of things that cause flicker.

On PWM lights, flicker is dependent on the frequency (i.e., how many cycles per second) and the pulse width (i.e., how long the light is "on" during each cycle). PWM needs to be very high frequency (i.e., >3 kHz), or run at a very high relative pulse widths (e.g., "on" 90% of the time) for you not to notice it. A lower PWM frequency can be acceptable, but will more likely be noticeable at lower output levels (i.e., when the light is "on" only a small fraction of the time – which is the whole point of lower levels). Note that the square-wave pattern of PWM (i.e., the jump from 100% to 0% output, and back again) is presumably a major feature as to why PWM "flicker" is so noticeable.

With lights that have variable or sinusoidal signals (like the LD60), the ability to perceive flicker is dependent on the signal frequency and relative amplitude. By amplitude, I mean how "strong" the signal is (i.e., to what degree it dims the output). Keep in mind that PWM is by definition 100% (i.e., light is on or off). Circuit signals like this run the whole gamut in between 0-100% relative intensity drops. As you would expect, you are more likely to see flicker if the amplitude of the signal is high. Also, I find actual PWM to be FAR more noticeable than even the strongest sinusoidal-like signal, when running at the same frequency. Again, I suspect the square-wave pattern of PWM (i.e., sudden jump to off/on) – as opposed to the more gradual sine-wave rise and fall - is a strong contributor to the visual flicker perception effect.

For the LD60, the frequency is unfortunately rather low – it ranges from ~154 Hz through to ~266 Hz (from Eco to Hi). It is a little hard to interpret relative amplitude from the oscillope traces above, but these seem fairly high on the LD60 (based on a comparison to other lights where I've observed this effect). However, the signal pattern here shows an increasing trend of moving toward a full sinusoidal pattern by Hi (which is definitely less visually noticeable than the full PWM square-wave effect). 

*So, the ultimate question is: can you see this non-PWM reoccurring signal as "flicker" on any of the LD60 output modes?* This can be tough to answer, as it depends on how sensitive you are to flicker (personally, I find I am very sensitive). Speaking for myself (and this one sample), it is really only on Eco mode that I find the flicker to be potentially distracting. For Lo and Med, it is much harder to notice (i.e., harder to notice than actual PWM at these same frequencies). I cannot really see it on the Hi level, and it is of course not present on Turbo. These subjective results are not surprising to me, now that I have the oscilloscope traces above to observe the actual waveforms. I expect most people wouldn't notice any flicker at all, except perhaps on Eco. 

You might also be wondering if these signals affect the output/runtime efficiency of the light (i.e., like PWM does). In my experience they generally do not, but scroll down to my runtimes section for a comparison in this specific case.

Before I move on, I also observed a higher frequency pattern to the signal noise on the LD60. Shown below is a "zoomed out" version (i.e., longer timescale) for each of the modes above where a signal was detected. These higher-order patterns are not anything you will be able to see by eye.

LD60 Eco mode:





LD60 Lo mode:





LD60 Med mode:





LD60 Hi mode:





Again, these are not an issue – I only provide them here for testing completeness.

*Strobe*

The LD60 has "tactical" strobe:






The light switches between two strobe frequencies – 7.2 Hz and 13.9 Hz - every 2 secs. Here's a blow up of the individual frequencies:










*Standby Drain*

Due to the electronic switch, the LD60 will always be drawing a small current when connected. I measured this current for a single 18650 (in any well) as 1.8uA. Assuming that remains constant as you insert extra cells, this would be completely negligible (i.e., would take centuries to drain your cells). 

You can easily lock out the switch to prevent accidental activation (and break the standby current), by turning the tailcap a quarter turn. 

*Beamshots:*

And now, what you have all been waiting for.  All lights are on their respective max rechargeable battery sources (i.e., 18650s), about ~0.75 meter from a white wall (with the camera ~1.25 meters back from the wall). Automatic white balance on the camera, to minimize tint differences. 





























































The LD60 definitely has an impressive output level on max. Beam pattern is about "typical" for a tri-head (overlapping well) reflector design – you get reasonable throw, with a lot of spill. There are of course artifacts in the spillbeam. The LD60 is perhaps a bit more focused for throw than some in this class, but not as much as the earlier Fenix TK75.

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. 
















Sorry, my centering was a little off for the TK75.  At this distance, the LD60 seems have to a larger (and more even) hotspot than the X40. I find the LD60 to be a good overall balanced thrower. 

*UPDATE OCTOBER 31, 2014:* For outdoor shots, these are done in the style of my earlier 100-yard round-up review. Please see that thread for a discussion of the topography. In order to compare the various tints of different lights, I have locked the camera to Daylight (~5200K) white balance. 



















As you can see, the LD60 is less of thrower than the TK75 (as expected), but does throw better than a single MT-G2-equipped light like the SX25L3 (again as expected). 

*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).






Initial max output (on 3x18650) is quite bright on the LD60 – slightly brighter than my TK75 in fact. Of course, it cannot throw as far as the TK75 – but overall throw is still quite respectable.

Another interesting feature is the ability of the LD60 to run on a lower number of 18650 cells (by activating a lower number of emitters). As you can tell from the simple summary table, this seems to proportionately lower the output. Let's see if that holds true at all levels:






And indeed it does – the reduced number of emitters (and 18650 batteries) produces exactly the expected reduction in output. Note that all the values above are direct measures in my testing setup. You will also note how well my standard calibration method for high-output lights matches the official Fenix specs. 

*Output/Runtime Comparison:*

Up until now, all my standard 18650 runtimes have been done using AW protected 2200mAh. Here is how the LD60 compares using those batteries. Since there are a lot of lights in this 3x/4x18650 class, I've broken the comparisons down into two groups, starting with multiple-emitter lights, followed by single-emitter lights:



















As with many high powered lights, the LD60 steps down from Turbo to Hi after 3 mins runtime.

As you can see above, the LD60 has excellent efficiency at all levels for the class and number of cells. It also has very flat regulation at the Hi and lower modes, for a good length of time. The output trails off as the batteries near exhaustion, giving you plenty of advance warning. :thumbsup:

I have been testing a variety of brands of protected NCR18650A cells lately (3100mAh capacity), to see if I can provide runtime comparisons that are more relevant to today's cells. This is not as easy as it may sound, since not all brands will fit in all lights (unlike the 2200mAh AW cells). But I have found a range of brands that show good correlations and internal consistency. As such, here are some additional graphs showing performance on 3100mAh cells.



















I will start providing both sets of 18650 runtime comparisons from now on with these lights, and plan to eventually switch to 3100mAh runtimes exclusively (once I have a large enough sample set). :wave:

One question that always gets asked is how does the light perform with multiple re-starts after the Turbo/Hi step down? For this, I let the light cool for a couple of mins once step-down occurred, and then re-started the light on max. I've removed the off periods from the graph below, for a better visual comparison.






The light is able to maintain a fairly consistent Turbo output for ~20 mins or so (on fresh cells). After that, Turbo output slowly drops off until it approaches the defined Hi level.

As mentioned, another interesting feature is the ability of the LD60 to run on a lower number of 18650 cells (by activating a lower number of emitters). Since output is proportionately decreased (see my earlier Lumen estimate table), this should produce roughly equivalent runtimes.






And so it does.  You can thus safely run reduced cells, and still predict total runtime at all levels.

*Potential Issues*

My LD60 sample shows a reoccurring signal in the potentially visible "flicker" range of ~155-265 Hz, on Eco through Hi. This is NOT pulse width modulation (PWM), but it could still be potentially visible. I am personally sensitive to flicker, but was only able to notice it visually in use on the Eco mode (although I could spot it on Lo/Med if I went looking for it). In any case, I found the subjective flicker effect was not as visually noticeable as actual PWM at those same frequencies would be. The pattern is there no matter how many emitters you are running. Just guessing here, but I presume this signal has something to with synchronizing the three independent circuit controls for each emitter. :shrug: See my detailed comments in the Oscilloscope section of this review for a greater discussion of the flicker effect.

User interface requires you to press-hold the single switch to turn the light on/off, and to click to cycle through modes.

Strobe mode is "hidden" through an extended press-hold. This means you need to move through Off or the last memorized mode, en route to strobe.

Due to the overlapping reflector design, there are some artifacts in the periphery of the spillbeam. The LD60 is about "typical" for this class, although these spill effects may be a bit disproportionate if you don't have all the emitters activated.

*Preliminary Observations*

The LD60 is an interesting departure for Fenix - a compact 3xXM-L2/3x18650 light that can run on a reduced number of batteries (and corresponding emitters). oo: This actually gives you a lot of potential output levels to choose from. 

Build-wise, I like the new compact design with integrated battery wells (i.e. no carrier any more). All my various sized cells fit and worked in the light - thanks to the dual head and tail springs. This is a much more portable size than the TK75. 

I also like the new single switch to control both on/off and mode changing. To be honest, I never found the dual switch design of the TK-series lights particularly intuitive (especially when switching hands – the curse of being somewhat ambidextrous).  The new user interface worked well, although with single switch designs I personally prefer click for on/off and press-hold for mode-changing. I do like that both momentary-on and constant-on strobe are "hidden" behind an extended press-hold.

Output/runtime performance was excellent at all levels on the LD60, consistent with other current-controlled Fenix lights. I particularly like the way each emitter is independently controlled by one battery well. This means that you will see a directly proportional decrease in output on reduced cells, with unchanged overall runtimes. 

One circuit feature that merits discussion is the reoccurring signal pattern on the Eco through Hi modes. Despite the concern expressed here, this is definitely not pulse width modulation (PWM). It is however potentially still visible as a form of "flicker" - but a less noticeable one than the equivalent frequency PWM would produce. With PWM, it is basically a numbers game – if you know the specific frequency, you can predict how visible it will be for you, for a given pulse width. But characterizing the visual impact of the sort of variable amplitude signal seen here (especially as it approaches a true sine wave) is not straightforward. I am personally sensitive to PWM flicker, and don't find my LD60 sample to be an issue on any mode from Lo on up (i.e., it is only on Eco where I notice it). Please see my detailed comments in the Oscilloscope section of this review for more info. 

The beam is about what you would expect for a 3xXM-L2 light with this size reflector - good throw, with a certain number of artifacts in the spillbeam. An interesting aspect is what happens when you reduce the number of emitters/batteries – the main spill effect from the other emitters are still there somewhat (due to light flooding into the open wells), but the overall hotspot is greatly reduced. See the video for an example of what this looks like.

The LD60 is a well-built, compact 3xXM-L2 light, with an innovative independent emitter/battery well control feature. The only real issue I note with this model is the potential flicker effect of the detectable circuit signal - but this is not as noticeable as PWM would have been (and overall efficiency is still typical of Fenix current-control lights). Personally, I like the move to a single button control user interface. As always, I welcome the feedback from members here on their preferences. :wave:

----

LD60 was provided by Fenix for review.


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## ruke (Oct 16, 2014)

as usual, awesome review SB!!!


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## Ryp (Oct 16, 2014)

Thanks for the review!


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## kj2 (Oct 16, 2014)

Thanks for the review, great that you explained the pwm/flickering-part.


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## skoor (Oct 16, 2014)

Great detailed review! Thanks

Couple of observation from a LD60 owner (to just give some more users input). I too like the single switch and found the TK75 also non-intuitive. Like the size and power options. Throw is def not in TK75 class, but nice spill probably makes it more everyday useful. If I understand the three separate circuits, the light should be a little bit safer then the 2P2S Tk75 circuit, since the cell ageing concerns should be non-existent even with protected cells and even more so with non-protected (I always use protected anyway). I was hoping parasitic drain would be low and review seems to indicate even for three active cells it should be very non-issue. My three led are also not perfectly centered, but seem better than the review sample. I also could detect no real significant centering artifacts even when looking at each led lit separately. Using all three, the centering errors seems to average out even more.

So what is left as any concerns? Only the "flicker". I personally can not see it on any levels except as Selfbuit said "if I go looking for it." I would consider myself moderately sensitive to flicker, so it is below my casual viewing threshold apparently.

I have been on the fence for a few weeks and seriously considering just getting a TK75 to avoid this flicker issue. But I don't like the TK75 size, prefer the LD60 single switch, don't really need the TK75's throw, don't like the TK75's 4 cells and needed battery carrier, like the LD60 power flexibility, like the LD60 lockout vs essentially none on the Tk65 lockout due to the carrier springs. And The $25 street price differential is not a significant decision swing factor.

So, I guess this light due to this review's confirmations of no serious issues, it is def leaning again toward the keeper slot again.


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## skoor (Oct 16, 2014)

Darn, when into a dark room to look real close at the ECO setting and see if I could detect any flicker again. This time I could. But as I cycled the light on/off and stepped the power levels cycles a few times, I could not again detect any flicker at ECO again. Strange. 


I am going to let the light cool off and try again, since either my eyes adjusted really quick to the flicker or the circuits/led heating up somewhat changed the flicker level somehow. 

Guess it is a minor problem, if just ECO, but the see it now and not later is a first for me.


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## Mr Floppy (Oct 16, 2014)

Great review once again especially the explanation of the flicker. I don't understand why Fenix has that though. It isn't intentional is it? Or is it?


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## selfbuilt (Oct 16, 2014)

skoor said:


> I have been on the fence for a few weeks and seriously considering just getting a TK75 to avoid this flicker issue. But I don't like the TK75 size, prefer the LD60 single switch, don't really need the TK75's throw, don't like the TK75's 4 cells and needed battery carrier, like the LD60 power flexibility, like the LD60 lockout vs essentially none on the Tk65 lockout due to the carrier springs. And The $25 street price differential is not a significant decision swing factor.


Thanks for adding your personal experience. And I agree, the LD60 does have a lot to commend it. Personally - and this is coming from someone who can't stand low frequency PWM - the subtle flicker effect here is not something that would dissuade me from using the LD60. 



skoor said:


> Darn, when into a dark room to look real close at the ECO setting and see if I could detect any flicker again. This time I could. But as I cycled the light on/off and stepped the power levels cycles a few times, I could not again detect any flicker at ECO again. Strange.


Eco is by far the most obvious mode for it (likely due to the least sinusoidal wave pattern). Interesting that you saw it change after cycling modes - I recall some people reporting that for LD12 as well (another light with non-PWM signals on sub-max modes). 



Mr Floppy said:


> Great review once again especially the explanation of the flicker. I don't understand why Fenix has that though. It isn't intentional is it? Or is it?


On the LD12 I presumed it was artifactual at first - and speculated it might be a component issue. But I came to doubt that after it seemed to be so common across batches (as reported here on CPF), implying it was integral to how the light operated somehow. In this case, I would normally presume it has something to do with integrating or synching the individual emitter circuits (although, I wonder why Turbo doesn't show it?) :thinking:

I never saw a clear explanation for the LD12, and I don't know if we will get one here. But I am curious as to what those with more circuit design experience think could be the reason.


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## skoor (Oct 17, 2014)

An update on the ECO flicker varying after going thru the power cycles. It def happens for me- sometimes. I can see the flicker on ECO. I leave the light running and I still see the flicker anytime I look over at least 30 minutes of running. But if I cycle thru again, I can find an ECO that does not flicker again. Strange. I might have to do it a few times to get one cycle that flickers again. Suspect it something into the light locking into at a slightly lower frequency that just happens be at my threshold of seeing flicker. The next time is must just be slightly higher and I don't see it.

Thanks Selfbuit for your comment on the value of this light without or without seeing flicker on ECO mode. I agree. It is just hard to ignore the other positive aspects of the light.


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## selfbuilt (Oct 17, 2014)

skoor said:


> An update on the ECO flicker varying after going thru the power cycles. It def happens for me- sometimes. I can see the flicker on ECO. I leave the light running and I still see the flicker anytime I look over at least 30 minutes of running. But if I cycle thru again, I can find an ECO that does not flicker again. Strange. I might have to do it a few times to get one cycle that flickers again. Suspect it something into the light locking into at a slightly lower frequency that just happens be at my threshold of seeing flicker. The next time is must just be slightly higher and I don't see it.


Interesting. I haven't been able to replicate this with my oscilloscope on my sample - the frequency and amplitude of the signals on the various modes remain constant, no matter how many times I cycle through or turn off/on. And personally, I don't see much of a difference either (although again, the flicker is never as noticeable as PWM would be).

FYI, Fenix informs me that they are following up with their R&D department, so I will report back what I find out. But in any case, I do consider this to be a minor point in the actual functioning of the light.


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## selfbuilt (Oct 20, 2014)

I've heard back from my Fenix rep on the flicker issue.

To paraphrase (and keep in mind that this going through an intermediary between me and their engineers), is seems the reason has something to do with the high efficiency integrated circuit Fenix uses for its current-control lights. Apparently, it suffers from reduced control accuracy when the current is set very low (e.g. Eco or Lo level, in this case). According to Fenix, this is the reason why they don't do Moonlight levels. The engineers believe this is the source of the perceived flicker on the LD60.

I am not an expert on ICs at all, so it's hard for me to respond. I have heard similar comments from at least two other makers of current-controlled lights where I detected visible flickering on the Moonlight modes of a certain model. However, in both of those cases, the flickering was irregular and limited to only the Moonlight level (which was lower than Eco here). In the case of the LD60, I can detect the circuit oscillations at all non-max modes (although can only visually perceive flicker at Eco and maybe Lo). :shrug:

I've also tested other Fenix lights with Eco modes where there was no oscillating circuit pattern. That said, I have seen these sorts of sine-wave-like patterns before on one other Fenix light - the LD12. So there does seem to be some sort of model specificity at play here that I can't explain. :thinking:


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## skoor (Oct 21, 2014)

selfbuilt said:


> I've heard back from my Fenix rep on the flicker issue.
> 
> To paraphrase (and keep in mind that this going through an intermediary between me and their engineers), is seems the reason has something to do with the high efficiency integrated circuit Fenix uses for its current-control lights. Apparently, it suffers from reduced control accuracy when the current is set very low (e.g. Eco or Lo level, in this case). According to Fenix, this is the reason why they don't do Moonlight levels. The engineers believe this is the source of the perceived flicker on the LD60.
> 
> ...



Thanks for the update! 

I did go ahead and return the LD60. Primarily because I was starting to see the flicker on ECO mode more often. But what pushed me over the edge for the return is how the light gets real hot running on high (1500lm). It does not take it long before it really too hot to hand hold at 72F temperatures. Hot enough I would wonder both about the life of the light and even more so the concern of the safety and life of the 18650 batteries.


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## Mr Floppy (Oct 21, 2014)

It looks like Vinh has fixed the flicker issue in his latest offering. That or he swapped the driver out completely. I wonder why this is so hard for the Fenix engineers?


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## ven (Oct 21, 2014)

As always thank you selfbuilt for you amazing in depth review the time and effort is highly appreciated!!!:thumbsup:

Its a baby tk75 to me,i love it,form factor is great,like a go to alternative to the tk75 imo (of course UI different and one button etc etc) but it is like a baby version....

As above Mr Floppy pointed out,vinh has worked his magic and sorted the issues and improved the UI imo greatly so goes without saying an ld60vn KT with u3 is on cards for me at a later date(i do hope you get one for a review) as vinh has really outdone Fenix. I know its down to cost,mass production so understand why Fenix may take certain decisions,be it not the best for some or even most.

Thanks again selfbuilt


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## selfbuilt (Oct 21, 2014)

Mr Floppy said:


> It looks like Vinh has fixed the flicker issue in his latest offering. That or he swapped the driver out completely. I wonder why this is so hard for the Fenix engineers?





ven said:


> As above Mr Floppy pointed out,vinh has worked his magic and sorted the issues and improved the UI imo greatly so goes without saying an ld60vn KT with u3 is on cards for me at a later date(i do hope you get one for a review) as vinh has really outdone Fenix. I know its down to cost,mass production so understand why Fenix may take certain decisions,be it not the best for some or even most.


I'm glad to hear Vinh has found a work-around. Given the new UI, I would guess he has completely replaced the circuit (hence the disappearing flicker issue). 

ven makes a good point - I think these things really do come down to a cost/mass production concern. It's part of the reason why we get fairly "random" cool white tint emitters on almost all mass produced lights - only the small batch/hobbyist can finely tune and select more expensive defined tint bins, neutral/warms, etc. Same issue with precise focusing, reliable absolute max output, etc. But the advantage for us is that the general mass-produced builds are often of good enough quality that a custom builder/modder can produce some pretty impressive results building off them (without all the exorbitant costs of having to tool up from scratch, etc.). This actually provides for a nice pair of cost points - people can go with the stock item at a good price, or they can pay a bit more for a more finely-tuned custom mod job. At the end of the day, I think we all benefit from the options this dual level of service provides. :wave:


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## skoor (Oct 21, 2014)

Looked at Vinh's site, I think he said the runtime was about 25% less. Not sure if he meant all modes or just the harder driven high, but that did seem to imply to me a new circuit. And perhaps why Fenix has the flicker- a trade-off of efficiency vs circuit control/stability at lower levels? 

Also, on the smart UI, I am not sure that I would like the light being turned on by just a touch. It seems you would always have to do a manual lockout vs at least some protection by the Fenix interface of it having to be held down for a second. Yeah, I know not much, but just a touch seems much too easy to have a light turn on also. Maybe if I used it, I would think differently.


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## ven (Oct 21, 2014)

Will pm link selfbuilt so not to distract review


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## Alex1234 (Oct 21, 2014)

Selfbuilt will you be reviewing the LD50vn from Vinh?


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## selfbuilt (Oct 21, 2014)

Alex1234 said:


> Selfbuilt will you be reviewing the LD50vn from Vinh?


Yes.


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## Alex1234 (Oct 21, 2014)

selfbuilt said:


> Yes.



i have one. best light ever !!! 50ish klux throw with a enormousness hotspot


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## BringerOfLight (Oct 24, 2014)

selfbuilt said:


> I've heard back from my Fenix rep on the flicker issue.
> 
> To paraphrase (and keep in mind that this going through an intermediary between me and their engineers), is seems the reason has something to do with the high efficiency integrated circuit Fenix uses for its current-control lights. Apparently, it suffers from reduced control accuracy when the current is set very low (e.g. Eco or Lo level, in this case).


They are likely (ab)using a buck regulator that's intended for voltage regulation (last I checked, there wasn't any high-current LED regulator well-suited for flashlights). The eco/lo mode traces look like they are shutting down the regulator and it then enters soft-start.


> I've also tested other Fenix lights with Eco modes where there was no oscillating circuit pattern. That said, I have seen these sorts of sine-wave-like patterns before on one other Fenix light - the LD12. So there does seem to be some sort of model specificity at play here that I can't explain. :thinking:


The LD12 pattern looks like the regulator has an analog reference voltage input (used for current limiting) that is fed via a PWM output from a microcontroller (the PWM output is used as DAC; the smoothing cap seems to be too small).

There is a good article from Analog Devices on using voltage buck regulators as LED drivers:
http://www.analog.com/library/analogdialogue/archives/47-03/smart_led_driver.html


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## selfbuilt (Oct 24, 2014)

BringerOfLight said:


> There is a good article from Analog Devices on using voltage buck regulators as LED drivers:
> http://www.analog.com/library/analogdialogue/archives/47-03/smart_led_driver.html


Wow, that was a lot of info - most of it way over my head, I'm afraid. But I appreciate you stopping by and sharing it here. :thumbsup:

Whatever the underlying control mechanism, I (for one) certainly found the flicker effect to be far more noticeable (and annoying) on the LD12. So much so that I won't use that light. For the LD60, it's really only an issue for me visually on Eco, which isn't something I'm likely to use much on a light this size.

BTW, I'd had an additional response from Fenix. They added that their engineers say that the range between the lowest and maximal levels contribute to this flicker problem (i.e., the range from 30 to 2800 lumens in this case, which is higher than typical for a Fenix light). I don't really know why it matters, but that is something they added.

They also say that the true moonlight level found on other makers has a "large resistance", requiring relatively high power consumption. This apparently goes against their design principles, which prize efficiency.

Personally, I am an efficiency buff myself. That said, I am also a practical and functionally-minded person - for small handhelds, I find it is a better to have a moonlight mode (even if it suffers from some relative loss of efficiency compared to the other modes on the light). But I certainly agree that there is not much need for a moonlight mode on the LD60.


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## bearbreeder (Oct 25, 2014)

exact same issue on the fenix HL55

http://www.candlepowerforums.com/vb/showthread.php?391005-Flickering-PWM-in-new-Fenix-HL55


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## skoor (Oct 26, 2014)

"The LD12 pattern looks like the regulator has an analog reference voltage input (used for current limiting) that is fed via a PWM output from a microcontroller (the PWM output is used as DAC; the smoothing cap seems to be too small)."


Wonder if that explains also the PWM "like" whine I heard? I think it was med or high. I have since returned the light, so can not check again But it was def making a buzz that I could hear in a quiet room. It was not really annoying, but something I noticed. And again, my PD35 was totally silent. 

Hope they (or we figure out what they did) and possibly make come changes later in the run. Overall, it is a nice light, as noted like a mini-TK75.


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## selfbuilt (Oct 26, 2014)

skoor said:


> Wonder if that explains also the PWM "like" whine I heard?


This is now off-topic for this light, but in general, I must say that I've never seen any clear evidence that audible hum/whine is associated with PWM. Hum is generally believe to be inductor whine, and I've certainly heard it on current-controlled lights. It seems to correlate to specific drive levels and voltage sources (which is why you hear it on some modes and some battery configurations, for a given light that exhibits it). This would fit with a physical vibration inside an inductor coil.


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## skoor (Oct 27, 2014)

selfbuilt said:


> This is now off-topic for this light, but in general, I must say that I've never seen any clear evidence that audible hum/whine is associated with PWM. Hum is generally believe to be inductor whine, and I've certainly heard it on current-controlled lights. It seems to correlate to specific drive levels and voltage sources (which is why you hear it on some modes and some battery configurations, for a given light that exhibits it). This would fit with a physical vibration inside an inductor coil.



Oh, Good to know that current controlled lights can make a noise also. Thanks


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## selfbuilt (Oct 31, 2014)

I've just updated the main thread with some outdoor beamshots. These are done in the style of my earlier 100-yard round-up review. Please see that thread for a discussion of the topography. In order to compare the various tints of different lights, I have locked the camera to Daylight (~5200K) white balance. 




















As you can see, the LD60 is less of thrower than the TK75 (as expected), but does throw better than a single MT-G2-equipped light like the SX25L3 (again as expected).


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## MaxBeam (Nov 2, 2014)

selfbuilt said:


> I'm glad to hear Vinh has found a work-around. Given the new UI, I would guess he has completely replaced the circuit (hence the disappearing flicker issue).
> 
> ven makes a good point - I think these things really do come down to a cost/mass production concern. It's part of the reason why we get fairly "random" cool white tint emitters on almost all mass produced lights - only the small batch/hobbyist can finely tune and select more expensive defined tint bins, neutral/warms, etc. Same issue with precise focusing, reliable absolute max output, etc. But the advantage for us is that the general mass-produced builds are often of good enough quality that a custom builder/modder can produce some pretty impressive results building off them (without all the exorbitant costs of having to tool up from scratch, etc.). This actually provides for a nice pair of cost points - people can go with the stock item at a good price, or they can pay a bit more for a more finely-tuned custom mod job. At the end of the day, I think we all benefit from the options this dual level of service provides. :wave:




+1 :thumbsup:


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## skoor (Nov 3, 2014)

In the throw night shots, is the LD50vn dedome really that green? Or just a camera artifact? If real, gosh, it looks awful.  It would seem like a high price to just get some more throw unless that was the only purpose of the light. Thanks


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## selfbuilt (Nov 3, 2014)

skoor said:


> In the throw night shots, is the LD50vn dedome really that green? Or just a camera artifact? If real, gosh, it looks awful.


The green tint is accentuated by the common daylight white balance on the camera. In real life, it is not as green as it likely appears above. For comparison purposes, I have no choice but to leave the camera locked to a common white balance - otherwise, you would get the even more misleading impression that there was no tint difference between dedomed and regular emitters.

mmander has an excellent photography thread comparing the different classes of dedomed emitters Vinh offers. Scroll down the whole thread to see numerous examples.


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## skoor (Nov 4, 2014)

Thanks, Selfbuilt! You are always so helpful.


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## brightnorm (Nov 11, 2014)

Selfbuilt,

Thanks for another excellent review, which inspired me to buy the LD60. Fortunately, I'm not sensitive to the flicker, and am enjoying the light very much. I think of it as a kind of junior TK75; my girlfriend calls it the TK75's "little brother".

However, I do have some criticisms:

- No electronic lock-out. I really miss this feature, which I've rarely found well-executed in any light except the Nitecore TM11. Three quick clicks are so unlikely to occur accidentally that it is almost as secure as mechanical lock-out. Why Nitecore dropped this excellent feature in the TM15 and substituted a 2-second press, (which resulted in accidental activation on at least two separate occasions) is beyond me. I'm also bothered a bit by the slight on-off delay. 

To lessen the chance of accidental turn-on I cut a hole in thick stick-on Velcro and surrounded the button so that it was slightly recessed. I used this same approach even more aggressively with the TK75, which made the light much more secure.

- Poorly designed holster. This may seem nitpicking, but I belt-carry all my lights and depend on holsters to quickly attach and detach, and hold the light securely. The closed loop holster requires partial removal of the belt along with any other devices in its way. This is especially inconvenient if it's on the buckle side of the belt. In addition, the holster itself doesn't hold the light securely because it is cut so low that the light can move laterally, even with the flap secured.

I modded the holster with a Velcro "double loop" that attaches it conveniently and almost as securely as a closed loop. However, the best holster was a Ripoffs CO-28A with a flap I modded from a Ripoffs CO-136. Although clip-on holsters can be "ripped-off" the belt, the Ripoffs CO (Clip-On) series provides remarkably secure attachment.

- Insecure tail standing. This can be fixed by inserting the holster string underneath the recessed portions of the tailcap. But why should this even be necessary? Fenix is such a fine company that these minor (and not so minor) inconveniences are puzzling. Another more egregious example is the complete lack of tail standing ability in the Fenix PD35.

At any rate, these criticisms aside, the LD60 is a terrific light, and I'm very glad I bought it.

Thanks, Selfbuilt!

Brightnorm


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## selfbuilt (Nov 12, 2014)

Thanks for perspective. The holster comments are particularly on point. A lot of lights don't even have a holster, and for many it seems to be a last-minute thought. A good holster wouldn't add much to cost, but makes a huge difference for usability. 

And I agree, proper lockouts are always needed. 

Sent from my Z10 using Candlepowerforums mobile app


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## tcglog (Nov 20, 2014)

Thanks for the review! Someone should get you the newer verstion of TK75 with 2900lm and 120+kcd though, it would be more fair to compare against that one.


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## martinaee (Nov 20, 2014)

brightnorm said:


> Selfbuilt,
> 
> Thanks for another excellent review, which inspired me to buy the LD60. Fortunately, I'm not sensitive to the flicker, and am enjoying the light very much. I think of it as a kind of junior TK75; my girlfriend calls it the TK75's "little brother".
> 
> ...



This is something I wish Fenix would do--- just make the base completely flat or at least have much smaller cut-outs. If I wanted to use a lanyard it will be outside while carrying. Indoors I'd rather have a super stable light to tailstand.


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## Grijon (Nov 26, 2014)

GREAT review, thank you selfbuilt!


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## Outlander (Jan 23, 2015)

Thanks for the review on this light.

Will Olight 18650 3400 mah batteries fit in this light?


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## selfbuilt (Jan 23, 2015)

Outlander said:


> Will Olight 18650 3400 mah batteries fit in this light?


Should be fine. I haven't tested that brand, but other 3400mAh fit inside the light.


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## gopajti (Jan 24, 2015)

Outlander said:


> Thanks for the review on this light.
> 
> Will Olight 18650 3400 mah batteries fit in this light?



yes,you can use LD60 with Olight 3400mAh batteries


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## Outlander (Jan 24, 2015)

Thanks guys!

Appreciate your help.


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## braddy (Aug 15, 2015)

I just took my first unprotected 18650s out of a battery pack, is it safe to run them in the LD60?

Since the LD60 has individual battery electronics for each battery slot, and Fenix has protection against over discharge, would it be safe to use these salvaged, unprotected batteries?


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## dazzleaj (Sep 4, 2015)

braddy said:


> I just took my first unprotected 18650s out of a battery pack, is it safe to run them in the LD60?
> 
> Since the LD60 has individual battery electronics for each battery slot, and Fenix has protection against over discharge, would it be safe to use these salvaged, unprotected batteries?




I have been using salvaged batteries in my lights for 5 years now. If a light has 2 or 3 cells in series, I go to extremes to be sure that I have cells that are in about the same shape and check their voltage several times during a couple discharges before I call them a team If they are all discharging at about the same rate, then they can stay together. I run the light for a while, remove the cells, keeping the order of insertion, and check the voltages; let them set a few hours and then check again. If the voltage is close every time I check them, they are a team! In a battery composed of 6 cells, I usually get one three cell team or two two cell teams. I have never found all the cell to be in the same shape. Perhaps in a new battery they would all be the same but Definitely not in an old battery. I seldom use the 3 cell teams in a light for more than a few minutes at a time though. I think it is just too unsafe. I usually use new protected cells from a trusted name I have read about in this forum in 3 and 4 cell lights. I have 12 Nitecore 3400 mAh in my TK75 (2 add on sections).

Now having said all of that, it is my humble and most likely incorrect opinion that because this light has one circuit for one LED that it is the same thing as having 3 flashlights duct taped together. In that case all you would do to unprotected cells would be to over-discharge them. I am looking at this light just for the purpose of having a "kick lumen" light that uses salvaged cells.


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## braddy (Sep 4, 2015)

dazzleaj said:


> Now having said all of that, it is my humble and most likely incorrect opinion that because this light has one circuit for one LED that it is the same thing as having 3 flashlights duct taped together. In that case all you would do to unprotected cells would be to over-discharge them. I am looking at this light just for the purpose of having a "kick lumen" light that uses salvaged cells.



Thanks for the reply, it seems that way to me as well, I'm very wary of using unprotected batteries, but for the LD60, I don't see how they can be of any meaningful risk.


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## Swedpat (Sep 18, 2015)

Thanks for another great review Selfbuilt(a bit late but anyway)!

LD60 is pretty much like a 4Seven MMU-X3 but with another design, UI and battery setup, and with much higher max output and about the same output at the high mode. I guess the beam profile is pretty similar.
When I look at your runtime graphs I see that the output at high is slightly higher than MMU-X3(the last version I have) and with twice the runtime. 
Of course 3x18650 outperforms a single 26650 so it's not a surprise. Interesting light indeed(But Fenix; why are you so restricted to offer neutral white options???).


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## brightnorm (Sep 28, 2015)

One additional comment. This excellent light has a relatively short run time at higher levels. 4x1650's would make a real difference in run time, especially at higher levels. The weight increase would be small, and the body could be less than 3mm wider, as Nitecore accomplishes in the TM11.

Brightnorm


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## dazzleaj (Oct 8, 2015)

brightnorm said:


> One additional comment. This excellent light has a relatively short run time at higher levels. 4x1650's would make a real difference in run time, especially at higher levels. The weight increase would be small, and the body could be less than 3mm wider, as Nitecore accomplishes in the TM11.
> 
> Brightnorm



I think they would need to have 6, not 4 due to the 3 emitters though. The big selling feature for this light for me is the ability to use 3 cells of varying health/charge. I have several lights that use cells in series or parallel or both (4 cell lights). This "3 on 3" or "1 on 1" configuration takes the danger out of cell choice. Who knows how cells bought together will age or even if they are really the same to start with without a bit of testing. Kind of takes the worry out of being bright!!


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## markr6 (Oct 8, 2015)

This light never really seemed to stand out. I don't hear about it much but really like the form. 3x18650 is pretty much my limit. I may keep my eyes open for a deal in the near future.


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## dazzleaj (Oct 9, 2015)

markr6 said:


> This light never really seemed to stand out. I don't hear about it much but really like the form. 3x18650 is pretty much my limit. I may keep my eyes open for a deal in the near future.



They had one in the clearance section of fenixoutfitters a couple weeks ago that was a return. Forget how much it was but it was a deal. Almost bought it, should have bought it but I had just ordered a Nitecore EA81. I really should get one of these while they are available. Actually, perhaps this is a good high output gift for the technically challenged that want big light. I have several in my family that kind of get a far away look in their eyes when I start talking about 18650 cells. Kind of like "I wish he would just shut up and give me one of those lights". fenixlighting has a package deal for 140 that includes 3 2300 cells and a charger. Less chance of a loved one blowing up his house and family that way perhaps.


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## braddy (Oct 9, 2015)

Having bought a used LD60 I wondered why there was little discussion of it, but after a few months, it has become my primary (none EDC) light.

I made a very smart buy, the LD60 is a super all-round flashlight for the house, the farm, for a yard or for acreage, and it is family friendly.


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