SureFire M3LT (MC-E | 3 x CR123)

SUREFIRE M3LT REVIEW
This is my first review of a Surefire light, the M3LT which also happens to be one of their newest releases. It was gifted to me as a combo Anniversary/Father’s day present from my family.


RELEVANT SPECS
- Lumens Outputs (Runtime) - HIGH: 400 (1.7hrs) LOW: 70 (8.5hrs)
- Weight (w/primaries) - 10.9 oz (309g)
- Length - 8.7" (22.1 cm)
- Bezel Diameter - 2.5" (6.4 cm)
- Power source - 3 x 123A Lithium



PACKAGING

The light comes in a foam -lined box that is encased in an outer shell box. Aside from the requisite manual, registration card and battery warning sheet, the only additional accessory included with the light is a lanyard and they also threw in a logo sticker. Of course the light comes pre-installed with Surefire batteries (as with all Surefire lights and in this case, three of them).


SIZE COMPARISON TO OTHER LIGHTS
Compared to other turboheads.

L to R: Surefire M3LT | Lumapower VX Ultra w/TF Kit | Jetbeam RRT-1 | Dereelight DBS V3


Compared to other Surefire's.
L to R: M3LT | U2A | E2DL | Z2 | G2Z


And here it is next to a M1X (3-cell configuration). The two lights are similar in overall size and its use of the MC-E. Where it really differs is in the head:




DESIGN / FEATURES
Despite sharing the same model name as the M3 line, the M3LT is not a simple LED reincarnation of its incan brethrens (a la G2 LED vs. G2) but rather a completely new design sharing no parts w/the M3 or M3T. It has the same recessed slotted elements as can be found on their newer lights (A2L, LX2, AZ2, etc.) and comes with a completely new head labeled, KX9T.


I find this interesting as it may indicate that they will eventually offer it for sale independently.

The light uses a 4-die Cree MC-E LED but alas, it is hidden behind a Fresnel Lens (pronounced: FRAY-NELL and thanks to Bill for pointing this out) which sits behind a semi-frosted main lens (at least they appear to be two separate lens).


This is truly a sight to behold when illuminated or not:


You can see this beam pattern of the Fresnel Lens as projected through a paper laid on top (left)

The pattern is also visible when projected close to an object (right), but quickly melds into nice smooth hotspot once you pull the light a few inches away from the object.


Per the main purpose behind a Fresnel Lens, the goal is to achieve better throw of oblique light using a lens in a more compact form vs. a reflector or traditional spherical lens. This is quite different than the TIR optic used to date in their lights (e.g. E2DL):


I’d have to believe the intent was to reduce the overall depth of the head as much space has already been allotted to five fins in the throat area. The head alone measures 2.67” from the tip of the semi-crenulated bezel to where the base meets the battery tube. The imbalance of the head to throat area gives the light an awkward look which to me bears an unflattering resemblance to a certain toilet plunger. While to me it ultimately doesn’t looks as sleek as the M3 or M3T, in the few days of ownership, the style has grown on me and I’ve come to really like the design a lot.

Incidentally, the fins must work pretty well given the quoted 400 lumens OTF on high for 1.7 hours (until the output drops below 50 lumens).* This is now twice the stated output of their next highest rated LED lights (ED2L, LX2) in their lineup while maintaining very reasonable runtimes. I’m really digging the direction they are headed.

*EDIT 7/12 - Runtime testing without use of fan seems to back up that the fins are quite functional.


The MC-E and Fresnel Lens combine to produce a really nice large hotspot w/very little spill which can be viewed in the beamshots to follow. It in essence produces a beam very similar to the E2DL but with even less spill. While this may not appeal to everyone, ultimately with fixed focus lights it boils down to horses for courses (what is your usage?).

I don’t know the primary demographic Surefire had in mind as the intended consumers for this light but given the form factor, I envisioned it to be used as a medium to long-distance search/spotlight with the focus being solely in the hotspot while still being a reasonable size. It provides the perfect balance between a pencil sized beam and a flood (and thus reduces the distractions to one's peripheral vision when used as such).

Removing the head and peering behind it, you will find that Surefire has installed a proprietary system to mount the LED, there will be no simple way of swapping it out like in the lights that use the P60 formats. There also did not seem to be a way to twist this module loose.

There was ample grease applied to the inner threads of the head.

The negative and positive contacts are both via springs with a wire soldered to each:

I've always found it interesting that on non-P60 formats, Surefire has chosen to go with some type of plastic resin as the base of their LED modules. This would seem counterintuitive in terms of heatsinking, however, I wonder if perhaps this was intentional as heat always seeks to "transfer" to a colder source and having a huge metal heatsink sitting within the head of the LED would only draw the heat there and ultimately trap it within the head whereas they may have designed a better thermal path for the heat to escape away from the head via the cooling fins. Of course this is all conjecture on my part and until the head is disassembled, we would not have any insight into the thermal design of the light (given the newness of the light, I'd be loathe to disassemble it just yet so I will not be entertaining any suggestions for such... ).

Continuing away from the head to the battery tube, you will find the standard laser etchings (model, patent #'s, etc.) and amongst them is Surefire’s new logo which seems to have been well received by the CPF community if initial responses are any indication:

I quite like the edginess to it vs. the more rounded profile of the old logo but I can’t really say I have a preference for one over the other. To me, they both look great and evoke feelings of quality, reliability and performance. Given the newness of this logo, there is inconsistency in it use as the manual and the box that came w/the light still had the old logo (likewise the included sticker).

The anodizing is flawless as can be seen in these close ups:


The battery tube is thinner than the head and tailcap a la Z2 and I've always been quite fond of this style over the standard 6P. Like the Z2, being designated a CombatLight, it features a CombatGrip wherein there are three rubber spacer rings (one flared) around the tube that one can move around to customize a more secure grip or for use with the Rogers/Surefire Technique.


I am neither a LEO nor in the military and don’t have a fighting bone in my body to speak of so will defer to those more knowledgeable about this. Interestingly enough, the instructions for the Rogers/Surefire Technique were not included with my light. I wonder if the omission was intentional given the girth of the light and potentially the impracticality of using it in such manner.

The great news though is that it can accomodate two 17500's (that's a AW peaking out the top):


Rounding out the light is the Lock-Out TailCap (LOTC) of which on mine was strangely missing the corresponding indent found on the body to allow alignment in the momentary-on position (M-OP). Here’s a pic comparing it to my Z2:


I can’t imagine that this was intentional and the instructions seem to imply that there is such a position under the Battery Replacement section (emphasis are mine): “Replace tailcap and rotate clockwise to the momentary-on position. Depress tailcap pushbutton switch to test.”. This would seem to indicate that there should be a known/visible M-OP. I will contact Surefire about this and post back when I hear from them. Ultimately, it’s not a big deal since one would just need to tighten the LOTC until low comes on and then unscrew it about 1/8th of a turn.

EDIT: I've found that Surefire's website imprinted on the LOTC acts nicely as the corresponding "indent" for one to align to M-OP with.

In spite of the new design, the light does retain the same thread on the body so that it can accept C, G, P, Z LOTCs (although you’ll lose High mode as explained in UI section) as well as M series heads (except M2 which is actually C series compatible in spite of the M designation, for more on M-series compatible heads, check this excellent thread out). To emphasize this point, here it is with a Z41 LOTC and TSL TX3 head (M body compatible):


While the M3LT’s LOTC will thread on to the Z2, it doesn’t engage even when fully tightened due to the increased thread depth.

After meeting with Monocrom, we swapped the heads between the M6 and M3LT. While the M3LT head will screw on fully to the M6 body w/no gap (L), it only functions in Low. The M6 head will NOT screw on fully to the M3LT body and leaves a gap exposing some thread and the O-Ring, it will not light up like this (R).


UI
The UI is very simple in that there are only two modes that can be accessed through one successive press of the pushbutton on the LOTC in the M-OP; depress lightly for Low and continue depressing further for High. The LOTC can be twisted a little past the M-OP to be locked in Low and further twisted to be locked in High.

There is a lot more thread on this light as opposed to a Z2:

EDIT: Upon further inspection, it only appears to have maybe 1mm more of thread, it's the combination of the longer LOTC as well as the space aft the threads that has increased.

The gap with the LOTC in M-OP is roughly 3mm (left) and increases to a full 7mm before it can be locked out:


This contributes to a lot more depth one can create for the feel of the pushbutton. For instance, there is a 1 ½ rotation gap one can loosen the LOTC from the M-OP and still retain both modes. By 2 full rotations loose from M-OP one can manage to lock out just the high mode and full lock out is achieved by 2 ¾ rotations. However, this also makes it a PITA to change batteries and gives your forearms quite a workout as it takes nearly 6 ½ full rotations before the LOTC can be removed from the M-OP!

While this UI has its merits, I’m not a huge fan of it. I may have to consider modding this in the future as I don‘t plan on entering the “Mr. Popeye Forearms“ or “America‘s Got Big Thumbs“ contests anytime soon. But what of the Z59 you say? Well you could install it but then you’d lose the high mode. From what I’ve read, the LOTCs in these 2-staged lights have a resistor in one of the stages to help trigger the low or high mode. However, I’m not certain why it then defaults to low mode when used with a Z41 (or a clicky from my U2A). I would’ve expected it to default to high mode. I’m sure one of you knows the answer to this and can reply in the thread after which I will reference the answer here.

Here you can see the telltale signs of a PCB board within the LOTC, again, I have no idea what the circutry does nor why the light defaults to low vs. high:

Anybody care to hazard a guess?


5M INDOOR BEAMSHOTS
All shots taken on stock Canon S3 IS @ f/2.7 using Sunlight WB as this was the most neutral I could get across all lights. Control shot taken @ 1/5" and all others @ 1/6".

CONTROL SHOT


Surefire M3LT (H | L)


Jetbeam M1X (OP) (H)


Surefire E2DL (200L) (H | L)


Surefire Z2 (OP) w/Dereelight XR-E WH R2 (H | L)


Lumapower VX Ultra w/TF Kit (SM) (H | L)


Jetbeam RRT-1 (SM) (H | L)


Dereelight DBS V3 (SM) w/nailbender's 3S SST-50(C) @ 2.5A (H | L)


Solarforce SS L2M (OP) w/supasizefries 3S SST-50(W) @ 2.5A (H | L)


Surefire KL4 Head (OP) w/SSC P4 on VitalGear FB1 (H) | Surefire U2A (OP) w/SSC P4 (H)


Against a smooth wall on H (M3LT | M1X) - 1/40", f/3.5



1M INDOOR BEAMSHOTS COMPARO BETWEEN M3LT & M1X
All shots taken on stock Canon S3 IS @ f/2.7 using Sunlight WB. Control shot taken @ 1/4" and all others @ 1/50".

CONTROL SHOT


M1X | M3LT


M1X | M3LT



OUTDOOR BEAMSHOTS
EDIT: 7/5
[DRAMA] Ladies and gents, while most of you were out partying or watching the fireworks or simply gathering w/family and friends over a BBQ, Monocrom and yours truly braved the 94 degree heat and dealt with sweltering as well as all sorts of stinging insects at Columbus Park in order to bring you these beamshots!
[/DRAMA]

OK, in all seriousness, here are the long awaited outdoor beamshots. Given time constraints, these were the best we could come up with for now and we only took High modes (since that's what these lights were intended for no?).

I think the pics speak for themselves so I'm not even going to put any narratives beyond the fact that the camera was in fact level and the ground not being level is some strange optical illusion. Don't believe me?, look at the bulding to the left and note that the windows are near perpendicular to the edge of the photo.

Lights used* (all batteries either freshly charged or brand new):

*RRT-1 used in second outdoor comparo shots in 7/12 Edit further below.

All shots on Canon Powershot S3 IS and locked in M mode (f/2.7, 3.2 sec) & Sunlight WB. Distance to trees approx. 30 yards. First three sets of beamshots are of the M3LT vs. a direct interest as voiced on this thread. The rest are paired w/similar lights.

M3LT | M6


M3LT (L) - M6 (R) | M6 (L) - M3LT (R)


M3LT | M1X


M4 | 6P


Z2 | E2DL


DBS V2 | VX Ultra


E2D


EDIT 7/12: Additonal Outdoor Beamshots w/some Comparo's
All shots on Canon Powershot S3 IS and locked in M mode (f/2.7, 1.6 sec [1/20 sec for Control shot]) & Sunlight WB. Distance to trees approx. 10 yards.

I couldn't find a good spot where I could do a side-by-side comparo so I did Top/Bottom instead and replicated by reversing position of lights. This is to give you a perspective of each so as not to give the bottom light an advantage due to it being just a bit closer as a result of the lower angle.

The patio umbrella and the side of the house should give you a better idea of the spill for each light's individual beamshots.

Control Shot:


M3LT Hi | M3LT Lo


M1X Hi | RRT-1 Hi


E2DL Hi | Z2 (NEOFAB D1000)


M3LT Top / M1X Bot | M3LT Bot / M1X Top


M3LT Top / RRT-1 Bot | M3LT Bot / RRT-1 Top


M3LT Top / E2DL Bot | M3LT Bot / E2DL Top


M1X Top / RRT-1 Bot | M1X Bot / RRT-1 Top


RUNTIME (High)
I'm not a big fan of primaries so I started off this test with a fresh set of 2 x AW protected 17500's which fits the same profile of 3 x 123A batteries. In spite of having roughly 71% of the capacity of a primary, it was only able to produce 42% of the stated runtime. However, the caveat is that these batteries have not even gone through one cycle yet so I will run additional tests in the weeks to come and will post updated runtimes as well as conducting tests on primaries.

Test Data (conducted w/fan on):



X axis = Time (min) / Y axis = Relative light output

As you can see the runtime for primaries lives up to and actually surpasses Surefire's claim of 1.7hrs (102min) before output drops below 50 lumens (12.5%), in which case, using the relative output above and the initial stabilized brightness at about 150, 12.5% of that would put it at 18.75 which is around the 120 min. mark or so. So there you have it ladies and gents, not only are they conservative with their output ratings but now runtime as well!

EDIT 6/26: RUNTIME w/actual Lux readings @ 1M (High)
Given the major disappointments around the non-regulation shown by this light, I decided to amend my testing procedures to standardize the readings of actual Lux values on my Extech HD450. Previously I had the light right against the reader w/a tissue over it to act as a filter to prevent OL (overload) readings. However, given the extreme proximity of the light, any slight change was a bit exaggerated whereas the readings out at 1M were more subtle in that regard.

Test Data (conducted w/fan on):

X = Time in min / Y = Actual Lux (k) readings @ 1m

I decided that the v difference between three fresh SF123A's @ 3.26v each for a total of 9.78 vs. that of the three LiFePO4's @ 3.37v each for a total of 10.11v was negligible so decided to proceed with the test. Again, these batteries are so new that they are each below 5 cycles so I expect these numbers to improve slightly in the future. I had purchased the AW LiFeP04's in anticipation of using it in this light, however after this test and seeing that it offers absolutely no benefits over the 2 x AW17500's despite the increased v, they'll be finding duty in my other lights.

To put the Lux readings into perspective, I took a reading of my 200 Lumens E2DL w/2 x LiFePO4's @ 3.37v @ 1M as well and it was 10K Lux, contrast that with the 29K Lux reading of the M3LT at the start and one can likely deduce that the M3LT is really putting out more than the stated 400 lumens (of course it can be argued that the E2DL might also be putting out more than 200L which would make the M3LT's output all the more impressive).

I conducted another runtime w/primaries, this time using 3 Energizer Photo Lithium's @ 3.26V each. The results are pretty similar with the Surefire's.

EDIT 6/27:
Per Bill's suggestion re: 10 min regualtion in reply #101, (as well as the inference from others starting from page 3 on of this review), I ran the light in 4 intervals of roughly 10 min or so with a break of usually no longer than 5 minutes in between (I intentionally input a 0 so you can see the straight drop to designate breaks).

Based on this, one can expect roughly 34 min of regulated runtime and 42 min total until complete shut off:

X = Time in sec / Y = Actual Lux (k) readings @ 1m

As you can see, when compared with the original straight run (black), the gains are subtle at best and I'm not certain if your eyes would pick up the added benefit anyway.

While I too would have loved to have the max lumens regulated for the full runtime stated for H, I'm of the same mind as Rocketman in that we are not the intended primary demographic that Surefire caters to (per his reply in #105).

If my life depended on a piece of illumination equipment, I'd definitely prefer to have it gradually dim over time to give me ample heads up that I need to change the batteries rather than have it die on me of all suddenly leaving me in potential pitch dark or even worse, imminent danger.


EDIT 6/28:

I conducted an abbreviated run on Low and stopped the test after 109 min as I didn't have time to go full 8.5 hrs. I may revisit this test in the future but for now, it's pretty near table-flat regulation. The graph looks very jaggedy due to the revised scale (only 5.4K - 5.8K) since looking at a flatline is rather uninteresting. I initially had the fan on but since it really didn't get all that warm I shut it off:


EDIT 7/12: M3LT vs. M1X comparo runtime (with and without fan)

I've never been fond of conducting runtime tests with the fan on. Why? When manufacturers produced these lights, especially ones of this size, I can't imagine they assumed that it'll always be used in cool climates or w/the owner holding their hands around the head/fins in order to act as a heat sink, otherwise, there should be disclaimers advocating use in this manner.

As an illumination tool, lights should be made and tested to survive reasonable use and with that in mind, I can envision a reasonable use where one simply lays the light on a flat surface in order to illuminate an area for an extended duration regardless of the temperature. I realize there are certain lights that instruct users to not run on H for prolonged periods of time but there is no such mention of this in the M3LT's or M1X's instructions. Besides, given SureFire's reputation for reliability and ruggedness, I don't think this is out of the realms of standard use for a Combat Light.

In this case, this brings out an interesting graph in terms of regulation:

*Runtime until output drops below 50% of initial captured lux. X = Time in min / Y = Actual Lux (k) readings @ 1m

As you can see, the M3LT declines for a bit starting around 9 minutes, however, it then sort of flattens out after some decline and towards the tail end, it actually looks like it's trying to boost before finally declining rapidly. I stopped the test when the output dropped to less than 50% of original output.

I overlaid this new runtime on the old one but couldn't get the exact position I used last so was not able to capture the same exact output but they are pretty close. What is not shown here due to me filtering out data by the minute (I capture in seconds) is that the light actually flickers a bit after it heats up. Overall, you lose on average 4K lux but gain roughly 7 minutes before output drops to less than 50%.

The M1X is fairly even keeled in this regard, averaging 1K and 1 min more. However, what is not shown here is that the M1X actually got hotter than 132F approx. 25 min in to the run and I had to use a fan and it skewed the output as it started increasing output as the light cooled off. On the second run (which is the data shown above), I used a fan momentarily as the light hit >130F towards the very end of the run.

The M3LT by contrast never got warmer than 127F, guess those copious amount of fins are more than just design details.

EDIT 4/15/11: CURRENT DRAW
I measured the draw on H @ 2.1A (w/the 2x17500's slightly depleted to around 3.95V). Interestingly, it looks like the resistance from the meter has triggered the light to go into H mode so I've confirmed the electronics that governs H/L is in the head and not in the LOTC. Will conduct additional testing using an actual resistor when I acquire one.


CONCLUSION
This is the first foray into both high output and multi-die LEDs (edit: it's not actually the first use of multi-die LED per this reply) for Surefire and I really liked the results. A search of the forums will yield many spirited debates on the cost to performance factor of any brand of lights so I will obviously not go into that here. Suffice to say that when I first joined CPF, I was an unenlightened newb and just couldn’t understand what all the hype around owning a Surefire light was about. I even made my wife cancel what was supposed to be a surprise gift in the form of a U2 citing that cost to lumens factor ratio. Now two and half years, five Surefire lights and an enlightended status later, I understand why many continue to choose to spend their hard earned dollars on these quality lights. They may not always be the brightest but that has never been the ultimate goal for Surefire.

While my career does not require that I entrust my life to the equipment I use, I take great comfort and satisfaction that should I ever need to do so, my Surefire light will not fail me and while I haven’t had to invoke Surefire’s warranty thus far, the many posts I have read citing their positive track record assures me that they stand solidly behind their products.

Kudos to Surefire on this release, now let’s see some more!

Cheers,
Tim

BONUS: EYE CANDY




























OWNERSHIP UPDATE 4/15/2011
(reposting info lost in the crash)

Given the sentimental value this light holds, it has lived most of its life as a shelf-queen. Upon showing the light during the holidays last December, I noticed that it had developed what looked to be an oil smudge under the lens. I contacted SF and they mentioned it was a result of the inner lens pressing up on the outer lens and that it was a perfectly normal condition but issued me a RMA so I could send it in for repairs. I also sent a L1 that had a particularly green tint along with it.

Upon receiving the lights back, the L1 (which was brand new) had a small scratch in the bezel and a ding in the tailcap along with excessive threadlocker exposed. However, the beam was now a very nice white color and they shipped out a replacement tailcap.

As for the M3LT, I noticed that all the engravings were worn (before/after shots):




Excessive threadlock around the bezel:



Scuffed up o-ring w/excessive threadlock behind lens:



Additional oil smudges and a dent where the former one was "repaired":


Without going into full details, I basically expressed my dissatisfaction w/the repairs and that I received the light back in a condition that was worse than when it went in. I was issued another RMA but have been sitting on the fence about sending it back again (given I have to pay for shipping/insurance) especially with no guarantees of the outcome. Will post updates should I finally do so.

While the service has left something to be desired, the M3LT hasn't. It is a great light and certainly one that will remain in my collection.

This is the older MC-E model but can still hold its own against the newer XM-L lights. It's still one of my favorite lights, just too bad what SureFire did to it.

Cheers,
Tim

You know Surefire threads get deleted here at BLF right…JK :stuck_out_tongue: Great review.