# Nitecore IFE2 (1x18650, XP-G R5, Continuously-Variable) Review: RUNTIMES, BEAMSHOTS+



## selfbuilt (Feb 20, 2011)

*Warning: pic heavy, as usual. *







*Manufacturer's Reported Specifications:*

LED: Cree XP-G R5
SmartRing II 'Infinitely Variable' digitally controlled brightness system- allows the user to preselect any output level or a tactical strobe mode.
Max output: 345 lumens, Min output: 0.003 lumens
Runtime: Min Output- 7 days, Max Output- 2 hours
Effective illumination distance: 133 meters
Powered by 2 x CR123A or 1 x 18650 Battery
Tailcap switch controls power on/off.
Made from military grade T6061 aluminum alloy for unprecedented durability
Mil-Spec type III Hard-Anodized scratch and corrosion resistant finish
Anti-rolling rugged design
Durable titanium alloy clip
Waterproofing Standard: IPX-8 (waterproof for 1 hour at a depth of 2 meters)
Dimensions: Bezel diameter- 0.92 in (23.4 mm), body diameter- 1.0 in (25.4 mm) with a total length of 4.96 in (126 mm)
Weight: 2.2 oz (62.4 g)
Package Contents: 1 x NiteCore Infilux IFE2, 1 x Lanyard, 1 x Spare rubber switch, 2 x Spare rubber o-rings, 1 x Instruction booklet
Estimated street price: ~$130.
It has been awhile since I’ve reviewed a Nitecore light. The IFE2 is certainly distinctive, and seems to be something of a refresh for the maker. How does it compare to others in yhe XP-G R5 class? Scroll down and see. 










Packaging is fairly typical Nitecore. Inside the hard cardboard box with magnetic closing clasp is the light in cut-out foam, with a wrist strap, spare o-rings and boot cover, manual, and warranty card. 









From left to right: CR123A, AW protected 18650, Nitecore IFE2, 4Sevens Quark 123-2, Klarus NT20, Eagletac P20C2-II, ITP SC2. 

*IFE2:* Weight: 65.1g (no battery), Length 127.1mm x Width 23.6mm (bezel)

As you can see from the photo line-up, The IFE2 is quite small for this class of light. In fact, most of the other lights this small can’t take protected 18650 cells (i.e. body diameter is too narrow). You are lucky if protected 17670 will fit – and often have to go down to 14670. I’m happy to report the IFE2 body takes all my protected 18650 cells. :thumbsup:

However, most of my recent high-capacity cells (even the button tops) wouldn’t light up the IFE2. I believe this due to top of the cells not fitting into the head opening (which is slightly narrower than the body on my sample). Certainly, flat-tops or large button-tops won’t work, as there is a raised disc around the positive contact surface in the head (see below).














Tailcap threads are anodized for lock out. The light cannot tailstand. Knurling is not overly aggressive, but the number of body elements helps with grip. Clip is fairly basic, and held on with Allen screws. 

Anodizing is excellent on my sample, no chips in the dark gray natural finish (HA = type III). The color is a departure for Nitecore - it looks almost silver-gray. Lettering is sharp and bright.

Switch is a forward clicky, with a slightly longer than typical traverse. 










The IFE2 features the Cree XP-G R5 Cool White. The reflector is textured to what I would consider a medium orange peel (MOP). The head opening is not very large, so I would not expect much throw from the IFE2.

Which brings us to the requisite white wall hunting . All lights are on Hi on 18650 (AW Protected where available), 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. 





























































As you can see, the IFE2 is definitely not a thrower. I found the beam to have a pleasant transition from hotspot to spill. Scroll down to my Summary Tables for more specifics on output and throw.

*User Interface*

Turn the light on by the tailcap switch. Half-press the tailcap for momentary-on, click for locked-on 

Mode switching is controlled by the magnetic control ring in the head. The IFE2 features a continuously-variable interface – you control the output level by twisting the ring. You can select your desired mode while the light is off. 

The ring traverses a little over 2/3 of the circumference of the light. There is one clear and firm detent just below the minimum output, which is a standby mode. Interestingly, strobe is “hidden” just below this detent (i.e. turn the ring a little past the detent to activate strobe).

*Ramping Pattern*

_EDIT: this section has been updated and revised from my initial post._

The big question is whether the output selection of the IFE2 is "visually linear". Generally, here on the forums, that has been taken to mean a logarithmic ramp as opposed to an actual linear ramp of outputs. The reason for this is that we perceive brightness in a non-linear way (actually, not just brightness - most of our sensory perceptions are non-linear). This is why twice the lumens doesn't appear twice as bright to us - lumens are an objective (linear) measure of output, and our subjective perceptions are not linear.

A logarithmic adjustment has long been used to adjust for our relative visual perceptions (e.g. the stops of camera are logarithmic). And like most here, up until now I have found that all continuously-variable lights with a logarithmic correction of output generally look "visually-linear". And then the IFE2 (and Sunwayman V10A, which shares a similar circuit) came along.  

To start, here is what the IFE2 looks like in my lightbox. To measure this, I slowly turned the ring at as close to a constant rate as I could manage, over ~40 secs or so. My lightbox collected output readings every second, and I then plotted the relative lightbox output against the estimated degree shift of the ring (i.e. with 360 degrees being a complete turn). Note the ring turns a little over 2/3 the circumference of the light, or about ~280 degrees.






I have blown-up the first third of the ramp in the inset graph, to show you that output does indeed increase over the whole ring (albeit seemingly slowly at first). Now, you can certainly argue that the output trace looks like it could be logarithmic. Indeed, if you plot it on a log scale, you get something approximating a straight line. However, the IFE2 does NOT subjectively appear to me to be visually-linear when handling (e.g. it does indeed spend a lot of time at the very low outputs over the first third of the ring).

Upon reviewing the scientific literature, I see that relative power relationships have superseded simple logarithmic corrections for linearizing our sensory perceptions. For perceived brightness, the currently accepted linearization method is actually a cube root of output. For a full discussion of this - including detailed graphs and primary literature references - please see post #3 in my V10A review.

When plotting with a cube root transformation of my lightbox's output scale, you get the following graph:






This graph MUCH better matches what I see by eye for the IFE2, compared to a logarithmic plot. :thumbsup: I have added the LiteFlux LF5XT (on 14500) to the graph, as it does both a linear ramp and a logarithmic step pattern. The linear and logarithmic ramps of the LF5XT also pretty closely match my relative perceptions. 

The point to the above is to show that the IFE2 goes to much lower outputs than any other linear or logarithmic continuously-variable light I've seen before. It also betters matches what I subjectively see across the whole range of outputs on these lights. So for now on, I will also include this type of plot (along with standard linear plots) for all the continuously-variable lights I review.

All that aside, I actually consider this dynamic range control of the IFE2 to be superior to a purely “visually-linear” ramp across the whole range. The logarithmic correction allows you to exquisitely fine-tune your low output selection. :thumbsup: And once you get into brighter outputs, the proportional increase seems quite linear.

Intrepid readers may notice that the IFE2 has almost exactly the same pattern and low level as the Sunwayman V10A which I have recently reviewed. Please see that thread for a greater discussion of the relative ramping patterns.

One additional feature of the IFE2 is the "hidden" SOS mode. To access, cycle the light rapidly from bright to low, to bright, and back to low. Turn off/on to restore regular constant output control.

*Current Draw*

You would hope that this wide range of low modes translates into a range of super-long runtimes. Unfortunately, the circuit overhead for this level of control is considerable, and Nitecore estimates only one week of runtime at the lowest level.

I have measured the battery current draw at both the standby detent and at the lowest output level, and get 11mA on 1x18650 in both cases. For a standard capacity 2200mAh 18650, that would translate into 8.3 days (consistent with Nitecore’s 1-week estimate). On 2xRCR (750mAh capacity), I measured 5mA, which would translate into just under a week.

*PWM*

I presume the light uses PWM for the variable outputs, but I was unable to detect the frequency with my setup (which means it must be in the high kHz range). It is certainly not detectable visually. :thumbsup:

At the highest output levels (i.e. over the last quarter turn of the ring), I was able to detect a weak signal in the 1.7-1.8 kHz range. This seems to be some sort of circuit artefact – it definitely isn’t the PWM freq, as you could easily spot those levels with an oscillating fan.

Once again, that is remarkably similar to what I noticed on the Sunwayman V10A. 

*Strobe*






Measured at 12 Hz in my testing.

*Testing Method:* 

All my output numbers are relative for my home-made light box setup, a la Quickbeam's flashlightreviews.com method. 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 recently devised a method for converting my lightbox relative output values (ROV) to estimated Lumens. See my How to convert Selfbuilt's Lighbox values to Lumens thread for more info.

*Throw/Output Summary Chart:*

*Effective November 2010, I have revised my summary tables to match with the current ANSI FL-1 standard for flashlight testing. Please see http://www.sliderule.ca/FL1.htm for a description of the terms used in these tables.*
















The max output and throw of the IFE2 are quite reasonable and consistent with its emitter and reflector design. The lowest output mode is incredibly dim - I can’t accurately measure it in my lightbox. Simply put, you can stare into the illuminated emitter quite comfortably at the lowest levels. :thumbsup:

*Output/Runtime Comparison:*














Note that although the specs do not mention 3.7V RCR, I found no issue with running my sample on 2xRCR. Of course, I presume that RCR is not officially supported, so you may run into a warranty problem if you encounter any issues.















Overall efficiency seems quite good across the range of levels tested, considering the continuously-variable interface and (presumed high frequency) PWM-control. Of course, a current-controlled light with a limited number of defined (and optimized) output levels would be expected to outperform at comparable outputs. But this is a very good result for a continuously-variable light.

*Potential Issues*

Flat-top and some high-capacity button-top 18650 cells may not fit in the light. Standard protected 18650 fit fine, though.

Clip is pretty flimsy, and doesn't inspire a lot of confidence.

The "hidden" SOS mode is activated by rapidly cycling from bright-low-bright-low. However, in practice I found it a little too easy to accidentally activate it (i.e. you don't need to do it too quickly, or over too wide a range of outputs). 

*Preliminary Observations*

The IFE2 is a very nicely designed light - I quite like the build and user interface. 

Certain aspects of this light seem like classic Nitecore to me, while others seem to have been brought over from other makers. I should point out that JetBeam and Nitecore are now owned by the same parent company, which may explain some of the “cross-talk” I’ve seen on recent models for both companies. In this case, I suspect Sunwayman is also involved with the circuit design somehow, given the close similarity in performance to the V10A I reviewed recently.

To start with the build, I personally quite like the minimalist size and style. Hand-feel is good, and the light is surprisingly light and easy to pocket. Pocket-clip is pretty basic though, and the switch feels a little light-weight. Be aware, this is not a beefy light.

I can believe the 0.003 lumen low level spec for the IFE2 – this light has probably the lowest low I’ve ever seen. oo: And the dynamic range of the continuously-variable control ring is excellent. While not consistently “visually-linear” in the classic sense, it is quite cleverly designed to allow you to access a very wide range of low outputs, and then quickly access a roughly visually-linear set of high outputs. This is only the second time I’ve seen this particularly useful pattern (see my Sunwayman V10A review for a comparison). 

IMO, one advantage the IFE2 has over the V10A is a much wider traverse of the control ring (~2/3 the circumference of the light in this case). Coupled with knurling on the ring for enhanced grip, it’s even easier to select the output mode you want here. The IFE2 has a standby detent below the lowest level, and strobe mode "hidden" on the other side of it. :thumbsup:

Like the V10A, I like the lack of detectable PWM on the IFE2 (rare on a continuously-variable light). Output/runtime efficiency seems very good across the range of outputs directly measured (again, surprisingly good for a continuously-variable light). However, the overhead on the circuit remains fairly high, and the estimated 1 week runtime on the lowest setting (or standby) seems believable.

FYI, Mrs seflbuilt is going to test this light out for me on her evening walking group walks. My preliminary impression is that the beam pattern and continuously-variable control ring would do well for this purpose, but I will wait for the expect assessment. 

_*UPDATE March 25, 2011:* Having used the IFE2 on walks, I remain very impressed with the interface and the beam profile. That being said, I find the "hidden" SOS mode a little too easy to activate in practice, and the ring traverse is probably a bit longer than it needs to be (i.e. half the circumference of the light would probably be ideal for me). But these are minor quibbles - the IFE2 has performed very well._

----

IFE2 was provided by Nitecore for review.


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## selfbuilt (Mar 10, 2011)

> Written by *AardvarkSagus* on 02-20-2011 11:25 AM GMT
> 
> Excellent review there (as usual) Selfbuilt. I always love seeing our reviews and impressions line up so closely.





> Written by *lewong* on 02-20-2011 11:31 AM GMT
> 
> Thanks for another one of your great reviews; they are always very informative and thorough.
> 
> ...





> Written by *regulator* on 02-20-2011 01:30 PM GMT
> 
> Thank you selfbuilt - excellent as usual. I have had this light for a little over a week and really like it. It is very comfortable in the hand and the control ring is easy to use one handed. I love the adjustable range on this thing. It is soo versatile. I also measured the same approximately 12ma lowest current draw. Basically once you get to this extremely low output, lowered the brightness does not conserve any more energy ( which is perfectly fine since it will run for a loooong time).
> 
> Efficiency seems pretty good on this light too with this fantastic UI. Nice job Nitecore.





> Written by *Budda* on 02-20-2011 02:16 PM GMT
> 
> excellent review, as usual.
> 
> ...





> Written by *LeifUK* on 02-20-2011 03:17 PM GMT
> 
> 
> 
> ...





> Written by *mhelskie* on 02-20-2011 06:59 PM GMT
> 
> Great review Mr. Selfbuilt, as always ^_^
> 
> pardon my ignorance but, is there any word about this light having parasitic drain?


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## selfbuilt (Mar 10, 2011)

_Written by *selfbuilt* on 02-21-2011 08:17 AM GMT_




AardvarkSagus said:


> Excellent review there (as usual) Selfbuilt. I always love seeing our reviews and impressions line up so closely.





regulator said:


> Thank you selfbuilt - excellent as usual. I have had this light for a little over a week and really like it. It is very comfortable in the hand and the control ring is easy to use one handed. I love the adjustable range on this thing. It is soo versatile. I also measured the same approximately 12ma lowest current draw. Basically once you get to this extremely low output, lowered the brightness does not conserve any more energy ( which is perfectly fine since it will run for a loooong time). Efficiency seems pretty good on this light too with this fantastic UI. Nice job Nitecore.


Thanks, it seems we all share similar impressions. It is a very comfortable to hold and easy to use light. I am glad to see the efficiency holds up well too. Thanks, it seems we all share similar impressions. It is a very comfortable to hold and easy to use light. I am glad to see the efficiency holds up well too.


lewong said:


> One thing I noticed from the tail cap photo was that the switch looks like a white version of the McGizmo's McClicky switch. I've never seen a white one before.


Interesting. I had noticed the switch looked distinctive - I can't recall seeing one like that before. Feel is also a little different from typical (a bit more of a traverse, somewhat "softer"). I haven't tried a McGizmo switch to compare, though. Interesting. I had noticed the switch looked distinctive - I can't recall seeing one like that before. Feel is also a little different from typical (a bit more of a traverse, somewhat "softer"). I haven't tried a McGizmo switch to compare, though.



mhelskie said:


> pardon my ignorance but, is there any word about this light having parasitic drain?


There is no parasitic drain so long as the tailcap switch is clicked off (or the tailcap is loosened for lock-out). However, there is a drain in the "standby" mode of the ring, (i.e. the detent between strobe and the lowest output). I measured this current as 11mA, the same as the lowest output current. That means you get about a week before you drain a fully charged battery/batteries. There is no parasitic drain so long as the tailcap switch is clicked off (or the tailcap is loosened for lock-out). However, there is a drain in the "standby" mode of the ring, (i.e. the detent between strobe and the lowest output). I measured this current as 11mA, the same as the lowest output current. That means you get about a week before you drain a fully charged battery/batteries.


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## selfbuilt (Mar 10, 2011)

> Written by *Cataract* on 02-21-2011 02:25 PM GMT
> 
> Thank for the great review. I was hesitant, but now I know I'll be spending some $$ on one of these.





> Written by *ss355* on 02-22-2011 09:56 AM GMT
> 
> Thank you for the excellent review, selfbuilt.
> 
> ...





> Written by *FireHawk007* on 02-23-2011 09:41 PM GMT
> 
> Great review as usual, Selfbuilt. I've had this light for over a month now & I just love it.


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## selfbuilt (Mar 10, 2011)

_Written by *selfbuilt* on Yesterday 08:54 AM GMT_



ss355 said:


> Your commentary regarding the dynamic ramping of the IFE2 being superior to visually-linear/logarithmic pretty much follows my brief, one-week experience with my copy. I find it quite useful to be able to adjust low levels so precisely yet access to high levels with ease. Before I purchased mine I was worried that the ramping adjustment would be at the expense at one end of the range, but I think Nitecore did a great job balancing access to the full ramping range.


Thanks. FYI, I have just revised that section of the review with more detail and new graphs. Thanks. FYI, I have just revised that section of the review with more detail and new graphs.

To make a long story short, my review of the research literature suggests a cube root power conversion of output data better matches perceived brightness (compared to logarithmic). This presumably explains why the IFE2 (and Sunwayman V10A) do not seem perfectly visually-linear across the whole range (i.e. this is the first time I've seen logarithmic-ramping lights that can go this low). It seems to me like the currently accepted cube root transformation for perceived brightness yields a better "visually-linear" match. 

For a greater discussion than what's in my revised first post, you can see post #28 in my V10A review.



> I did have an unfortunate incident with my IFE2 last night, though it still works fine. I had my copy clipped to my pocket, with the pocket clip outside and the light body inside my pocket. When I sat down in the seat of my car, Murphy took over and the clip bent away from the body of the light. It's sprung. I can remove the screws and bend the clip back to its original angle, but I'm afraid it won't hold under anything more than very little pressure. Any one know where I can purchase a sturdier clip? I'm not worried about weight.


Sorry to hear about your problem - but thanks for sharing it with us. The clip does seem to be a weak point here, as I could see it might get bent fairly easily. Hopefully someone can put you on to a good replacement option! Maybe contact your dealer for a replacement clip in the meantime? Sorry to hear about your problem - but thanks for sharing it with us. The clip does seem to be a weak point here, as I could see it might get bent fairly easily. Hopefully someone can put you on to a good replacement option! Maybe contact your dealer for a replacement clip in the meantime?


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## selfbuilt (Mar 10, 2011)

> Written by *BigBluefish* on Yesterday 04:01 PM GMT
> 
> Thanks for the excellent review, selfbuilt. This light has a very appealing feature set, though it's possibly less-than-tanklike construction and the perhaps less-than-sturdy switch (shades of the old NDI switches?) make me a bit hesitant, as I tend despite my best efforts, to beat the c--p out of stuff.
> 
> ...


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## selfbuilt (Mar 10, 2011)

The main review post has been updated with the final review text.

The thread discussions have been *fully restored* from the search engine cache data (thank you tandem!).

My last post in this thread was missing from the cache data, but it basically discussed the changes I made to the main post around the ramping process. Please see the main post for a revised discussion on the IFE2 ramp.

Please carry on!


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## enginesix (Mar 10, 2011)

a very well written review.


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## selfbuilt (Mar 25, 2011)

Having used the IFE2 on evening walks for a little while now, I remain very impressed with the interface and the beam profile. 

That being said, I find the "hidden" SOS mode a little too easy to activate in practice, and the ring traverse is probably a bit longer than it needs to be (i.e. half the circumference of the light would probably be ideal for me). But these are minor quibbles - the IFE2 has performed very well


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## SCEMan (Mar 25, 2011)

Another extremely useful review - great work! 
I too have been very pleased with the IFE2 and its wonderful UI. I find the ramping travel perfect, any shorter and it would be too abrupt and difficult to fine tune the levels. But I don't use it for nightly walks where one might want to go quickly from low to high. For me, it's mainly a travel or "grab and go" light, perfect for any situation. Especially with the "hidden" strobe and SOS modes. I swapped the tailcap boot for a shorter one that allows it to tailstand - simple fix that Nitecore should have provided. Great fit & finish and the best knurling I've seen on any light so far...


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## Raccoon (Apr 1, 2011)

Thanks for this review. I've mulled over it several times over the past month or so, but only one thing is stopping me from buying one right now. I am undecided on whether I want to buy a model with the Orange Peel (OP) reflector, or the Smooth (SMO) reflector. I understand the differences to expect between these two types of reflectors, but it's impossible to exactly convey the extent of these differences without seeing a side-by-side beamshot.

Would anyone on this forum have access to one of each Nitecore IFE2 of both reflector types, to take some side-by-side beamshot photos and possibly a video, too?

I would greatly appreciate it, and I'm sure others would too.

PS. Thank you for reconstructing this thread. Great job! Though, some of your reconstruction includes repeated paragraphs. Thank you for reconstructing this thread. Great job! Though, some of your reconstruction includes repeated paragraphs.


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## RBWNY (Apr 1, 2011)

SCEMan said:


> Another extremely useful review - great work!
> I swapped the tailcap boot for a shorter one that allows it to tailstand - simple fix that Nitecore should have provided. Great fit & finish and the best knurling I've seen on any light so far...



Convinced from your review...I just got the IFE2 yesterday and am very pleased as well  I also think I'll try switching the boot cap. Great suggestion!


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## Raccoon (Apr 1, 2011)

RBWNY said:


> I also think I'll try switching the boot cap. Great suggestion!


If you find a boot cap that fits and allows the light to tail stand, do post a follow-up.


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## RBWNY (Apr 2, 2011)

SCEMan said:


> I swapped the tailcap boot for a shorter one that allows it to tailstand - simple fix that Nitecore should have provided.


 
When removing the boot, did you gain access from the boot itself, or by removing the spring/switch from inside the tailcap?


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## RBWNY (Apr 2, 2011)

RBWNY said:


> When removing the boot, did you gain access from the boot itself, or by removing the spring/switch from inside the tailcap?


 
Nevermind. I figured it out... except the spare boots I had were a bit too shallow and once installed it wouldn't allow the switch to click on/off. Back to the original now. :ironic:


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## SCEMan (Apr 2, 2011)

The tailswitch unscrews "clockwise"?!? which is a first. I found that the GITD boots from the infamous Chinese supplier fit and function better than the OEM part, and tailstand also. Of course I had to completely remove the post from inside the boot.


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## nanotech17 (Apr 8, 2011)

i use McClicky Switch Module in mine and it feels better & brighter.


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## selfbuilt (Apr 8, 2011)

SCEMan said:


> The tailswitch unscrews "clockwise"?!? which is a first.


Actually, I am seeing this feature to pop up increasingly now. It has the advantage that the tailcap assembly doesn't loosen accidentally with screwing/unscrewing of the tailcap. With tradional threading, this is often the source of why a light may suddenly stop working after a battery change - simply tighting the switch assembly resolves the issue, but this may not be obvious to new flashlight enthusiasts. So reverse threading is actually a clever idea.


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## skyfire (Apr 10, 2011)

Thanks again for another great review!

this light has recently peaked my interest, especially with your fondness of it. 

im wondering how "E" series tailcaps and McClicky tailcap(McTC) would fit, function, and look on the IFE2?
anybody tried them out?
-nantech, can you please elaborate if any extra fit issues had to be resolved for the McClicky switch? can it tailstand with the mcclicky?

and has anybody opened the head for an emitter swap? Im wondering how complicated, or easy it would be.

thanks!


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## MAGnot (Apr 11, 2011)

Another super informative and enjoyable review selfbuilt, thank you! 
I've been eying this torch for some time now and am having to force myself not to click the "buy" button every time I view it. It has everything you would want in a 2Xcr123 form factor with infinite brightness. The only thing that's stopping me is, like you mentioned in your great review, the fact it's not a 'beefy' light. It does look a tad delicate from the pics and have always wondered why it didn't follow the same design as the IFE1 or IFD2? The latter two, IMO, are beautiful lights in their form and the use of stainless steel in the head. 
Performance wise it seems to be a real winner, but aesthetically not as "beefy" as other Nitecore offerings. I'm really itching for a 2Xcr123 variable light, but I think I'll wait a tad bit longer and see if they (Jetbeam/Nitecore) come up with a different model maybe upgrading the RRT-2......Sunwayman maybe.....


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## SCEMan (Apr 12, 2011)

selfbuilt said:


> Actually, I am seeing this feature to pop up increasingly now. It has the advantage that the tailcap assembly doesn't loosen accidentally with screwing/unscrewing of the tailcap. With tradional threading, this is often the source of why a light may suddenly stop working after a battery change - simply tighting the switch assembly resolves the issue, but this may not be obvious to new flashlight enthusiasts. So reverse threading is actually a clever idea.



Kudos to Nitecore for a simple solution to a common problem :thumbsup:


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## LSH001 (Apr 12, 2011)

selfbuilt,thank you very much for your good job.It is very helpful to me .


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## Nyctophiliac (Apr 17, 2011)

Very nice review as usual.

Just picked up one of these and I'm very happy with it. I have the smooth reflector and the throw seems quite usable for a larger pocket light. No probs with any of my 18650 cells thus far. Seems to be my go to light of choice now.


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## kalifornian (May 13, 2011)

Hello to the forum. New poster here and rookie flashlight addict. I was thinking of adding the IFE2 to my collection and wanted to know if Ultrafire's 3.6v RCR123A will fit. It states that the battery is about 1mm longer than standard.

Thanks in advance for the information.


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## CKOD (May 13, 2011)

The AW 2900 that I use in mine is ~68.8 mm long with the solder bump I added to make not a flat-top and it fits nicely, but measuring and poking around with my calipers, I dont think I'd use anything past 69.5mm, maybe a tad less, as the spring is nearly compressed already. if your cells are <34.5mm you should be fine. AWs protected RCR123s are 34.3mm long according to his information, so it might be a bit close with various protected cells, depending on how much the button nests into the cell in front of it. Unfortunately I dont have any RCR123s to try.


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## RBWNY (May 13, 2011)

kalifornian said:


> Hello to the forum. New poster here and rookie flashlight addict. I was thinking of adding the IFE2 to my collection and wanted to know if Ultrafire's 3.6v RCR123A will fit. It states that the battery is about 1mm longer than standard.
> 
> Thanks in advance for the information.


 
Not too trusting of ULTRAfire... but have used Trustfires and AW's. They both fit fine.:thumbsup:


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## kalifornian (May 14, 2011)

Thanks for the info.


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## whisky (May 16, 2011)

very professional report!! Thumbs UP
Please carry on!!!


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## Sunflash (May 16, 2011)

Very helpful.


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## zs&tas (Jun 20, 2011)

Im wondering how well it does on one rcr123 ? or imr ?


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## fyrstormer (Jun 20, 2011)

zs&tas said:


> Im wondering how well it does on one rcr123 ? or imr ?


How would you run it on a single RCR123? The battery chamber is too long and the head is threaded differently than the IFE1 is, so the battery tubes aren't interchangeable.

As for using an IMR, I don't think any of the IFE lights use power at a high-enough wattage to justify using an IMR battery. Normal RCRs should be able to provide enough wattage down to their cutoff voltage.


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## zs&tas (Jun 28, 2011)

didnt realise they had different threads ! glad you said.........


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## kalifornian (Aug 2, 2011)

Hi Selfbuilt,

What is the advantage of using 18650 vs 2X CR123A? More output or just the ability to recharge.

Thanks.


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## selfbuilt (Aug 2, 2011)

kalifornian said:


> What is the advantage of using 18650 vs 2X CR123A? More output or just the ability to recharge.


Mainly longer runtime, and ability to recharge (note that I use only 2200mAh capacity cells in my testing for backward comparability - most here now use 2600-2900mAh cells).

1x18650 is potentially safer in use, as you do not have the risks inherent in 2x setups (i.e. reverse charging of one cell by another, potential risk of one cell being defective, etc). That said, the risks with either source are fairly low. The other difference is that the risk with primary CR123A is mainly during the discharge phase, but with rechargeable Li-ions it is mainly during the charge phase. See the discussion threads by the various experts in the "electronics - batteries included" subforum here for more info.

Where possible, I personally prefer to use 1x18650 - although I may travel with primaries, if I'm going to be "off the grid" for any length of time.


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## jhc37013 (Aug 11, 2011)

I'm considering this light has anyone tried using Redilast 18650 yet?


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## scot (Aug 11, 2011)

I just tried a couple of the new Redilast 3100 mah cells in this light and they don't work. They fit in the tube but the light won't turn on.


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## jhc37013 (Aug 11, 2011)

scot said:


> I just tried a couple of the new Redilast 3100 mah cells in this light and they don't work. They fit in the tube but the light won't turn on.



Thanks scot I to have some RL 3100's I was thinking of using in this light but I figured after selfbuilts report they wouldn't work, thanks for the confirmation. I guess if Redilast and AW2600/2900 won't fit the next best thing may be Eagletac 2400man.


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## scot (Aug 12, 2011)

I use AW 2200 mah, no complaints.


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## selfbuilt (Aug 12, 2011)

jhc37013 said:


> Thanks scot I to have some RL 3100's I was thinking of using in this light but I figured after selfbuilts report they wouldn't work, thanks for the confirmation. I guess if Redilast and AW2600/2900 won't fit the next best thing may be Eagletac 2400man.


My Redilast 2600 and 2900 both fit in the tube, but will not turn on either. AW 2200mAh and Eagletac 2400mAh both fit and work in the light. I suspect it has to do with button top.


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## jhc37013 (Aug 27, 2011)

I've been carrying my IFE2 for the past couple days and I really like it, the light just has a really good feel to it and I like the pocket clip and how high the tailcap rides. I'm still have mixed feelings on control rings because they always seem to change outputs in my pocket so I'm never sure what exactly I will get when I pull it out my pocket but it's never to far from the original position I picked.

I really like the beam and find the XP-G really works well with this reflector giving a pretty god amount of throw from a small reflector, very attractive beam pattern overall. 

The only negative is the max output which is far less than advertised, I think if it was 350-375 it would be a good mix of output without to much heat. I do wish it was brighter but as it is it's plenty bright enough for a EDC light, my first reaction might be I wish they made a XM-L version but I like the throw out of this small reflector so I think I prefer it how it is and even if a XM-L version comes out I'm not sure I would choose to carry it over this XP-G version, however that would not stop me from buying one if NC decides to do it.


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## Ty_Bower (Feb 4, 2012)

selfbuilt said:


> Compatible with the Surefire E Series tubes.



I saw this, but am at a loss to figure out how. The E series tube has a male threaded connection. The IFE2 head also has male threads. Do these really go together somehow?


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## selfbuilt (Feb 4, 2012)

Ty_Bower said:


> I saw this, but am at a loss to figure out how. The E series tube has a male threaded connection. The IFE2 head also has male threads. Do these really go together somehow?


You are right, that doesn't make sense. I just quote the manufacturer/dealer specs in the intro of my reviews, I don't edit for content - my reviews do the correcting for output and runtime. 

But in this case, I'm guessing that's a dealer holdover error from another light description (maybe the earlier Infilux?). I'll take it out of the reported specs, as it doesn't seem right.


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## nsl18 (Apr 23, 2012)

i can see in offecial site gray-color body, but in http://hkequipment.net/index.php?sp=2&p=6&cat2=31&cat1=13&cat0=1&id=775&cat1=13&cat0=1&new=&more=&lang=en
has black-color version. this is genue nitecore or OEM?


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## selfbuilt (Apr 23, 2012)

nsl18 said:


> i can see in offecial site gray-color body, but in .. as black-color version. this is genue nitecore or OEM?


Manufacturer's can change their anodizing tints over time. If you are concerned, check with the manufacturer to see if a given dealer is an authorized dealer or not, that should tell you what you need to know.


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