Eagletac M3C4 SST50 - New SMO and Deep Reflector - Review: BEAMSHOTS, RUNTIMES, etc.

Originally posted: December 10, 2010

Warning: even more pic heavy than usual :sweat:

Eagletac has recently revised its M3C4 - SST-50 model (reviewed here) to a new version with a smooth and deep reflector for more throw. This review will compare to this version (labelled as SMO-Deep throughout) to the original M3C4-SST-50 (OP).

To make them easier to compare, my new SST-50 (SMO-Deep) is in the black body, while my original SST-50 (OP) is in the dark gray natural finish. :)

M3C4 SST-50 (SMO-Deep):

M3C4 SST-50 (OP)

Specs haven't changed - aside from the head/reflector. Common specs for the M3C4 SST-50:

Packaging hasn't changed from my earlier review. Included with the light are extra o-rings, wrist lanyard, warranty card and manual, primary battery holders, clicky-switch battery carrier, diffuser (swappable with the removable bezel ring) and a good quality nylon case that fits the light well.

M3C4 SST-50 (SMO-Deep):

M3C4 SST-50 (OP):

From left to right: AW Protected 18650, M3C4 SST-50 (OP), M3C4 SST-50 (SMO-Deep), M3C4 3xR5 XP-G with optional clicky switch installed.

As you can see, the height has increased. Basically, the new head is 7.2mm taller, and 19.5g heavier. Total dimensions are thus:

M3C4 SST-50 SMO-Deep: Length: 165mm, Width: 61mm (bezel), Weight: 354.2g
M3C4 SST-50 OP: Length: 158mm, Width: 61mm (bezel), Weight: 334.7g

Bezel diameter has not changed - the bundled diffuser and optional colored filters still fit as before.

The internals are the same, so the rest of these body photos are taken directly from my original M3C4 review. Please see that review for a more detailed discussion of the build.

Like other members of the M3C4 family, the light features anodized screw threads, allowing for head lock-out.

The lights come in the two types of type III anodizing, as shown above – dark gray or black. Regardless, the plastic control ring and tailcap cover are made of black plastic. Anodizing quality is top-notch on my samples. There is plenty of ridge detail to help with grip, plus some decent knurling on the head. Lettering is sharp and clear, bright-white against the dark background.

As before, the top of the battery handle still has four Phillips-head screws holding it to the battery tube portion. I would prefer that this were a single piece of aluminum – I recommend you periodically check these screws to make sure they don’t loosen up and compromise water-resistance of the battery handle.

No changes to the battery carrier. Note that flat-top high-capacity cells may not work in the carrier, as the plastic contact ring around the positive terminal is slightly raised. You can use CR123A cells with or without the included plastic holder.

The M3C4 series lights use small hex screws at the tail end of the battery tube. The included Allen key may be a bit small for some of the screws (i.e. you may need to find another similarly sized tool). Be very careful not to strip any of these screws when changing the tailcap - it can happen easily. If you encounter any resistance at all, back off and try again, or try a different screw (there are extras included).

For more on this potential issue, see my original M3C4 review and the discussion threads that followed.

Original M3C4 SST-50 OP on the left, M3C4 SST-50 SMO-Deep on the right

As you can see, the new SST-50 SMO-Deep is exactly that - with a deeper reflector and smooth surface. Here are some close-ups.

For examples of what the optional YRGB colored filter kit (yellow, red, green, blue) and bundled diffuser look like in action, see my original M3C4 review.


Here are some up-close shots comparing to the original M3C4s to my new SST-50 SMO-Deep. All lights are on 2xAW protected 18650, 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 new SMO-Deep version is listed as "Rev" in the beamshots below.

The original M3C4 SST-50 has a similar beam pattern to other lights with an OP reflector. The new SST-50 SMO-Deep has a more defined and tighter hotspot. Throw is now similar to the Catapult V2, but with a wider spillbeam.

I've recently updated my 100-Yard Outdoor Beamshot Round-up, including the latest M3C4 lights. Check out that round-up thread for more details on the testing method, plus higher quality JPEG images of all lights. For now, here is an animated GIF of relevant SST-50 comparisons:

Note: The new SMO-Deep version is listed as "*new*" in the 100-yard beamshots.

User Interface

UI is unchanged. To turn the light on, turn the control ring clockwise (with the light pointed away from you). The light will proceed out of Standby and through Moonlight, Lo, Med, Hi and Turbo in sequence.

To access strobe, rapidly switch from Turbo to Standby and back to Turbo again. This will replace Turbo with Strobe. Do this switch again to advance to Beacon, and again for SOS (note the manual has Beacon/SOS order reversed). Do it once more to return to standard output modes with Turbo.

Alternatively, you can loosen the head (or click off the optional clicky switch) to break the connection to the battery carrier and fully shut off the light. This also restores the standard output modes upon re-activation.

Note that the light moves through the output levels in a gradual fade into each level over ~1sec or so as you turn the ring (i.e. you don’t see a sharp jump/drop in output).

With the forward clicky switch module installed, the light can be turned on in any mode by the switch (with the control ring controlling the output level as before). There is no standby current with the clicky switch in the off position.

Note that there is a ~1sec lag to activation when the clicky switch is soft-pressed or clicked on. There is also a Med output “pre-flash” if you activate the switch with the ring in the Moonlight or Lo mode state (i.e. the light comes in Med, and fades down to Lo/Moonlight).

My new SST-50 SMO-Deep seems to have an issue on its Moonlight mode - the output is extremely low (i.e. can stare into it comfortably), and flickers slightly. I can't get a reliable lightbox reading at this ultra-lo level. I suspect this is abnormal on this sample, and the Moonlight modes of the other two M3C4s are the norm.

Parasitic Standby Drain

The M3-series lights have a parasitic standby drain. I haven't re-measured it yet, but got 1170uA on my original SST-50 on standby mode. That would translate into 78 days before fully charged 2200mAh batteries would be completely drained. :caution: I therefore recommend you store the lights with the head locked-out, or use the optional clicky switch battery carrier. There is no standby current with the switched clicked in the off position.


All M2- and M3-series lights appear to be fully current-controlled at all levels (so no PWM). :twothumbs


Strobe is unchanged at 7.9Hz.

Beacon is a slow strobe, at 2Hz freq.

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.

As you can see, peak center-beam throw has increased considerably from the earlier model. The new M3C4 SST-50 SMO-Deep is now closer to the Thrunite Catapult V2 in overall output and throw.

Note that the lowest output level (Moonlight) is too low to measure on my new SST-50 SMO-Deep sample. :thinking: I suspect this is a defect, since the light seems to flicker at this ultra-low level. I expect the light should be more like the earlier M3C3 lights. :shrug:

Output/Runtime Comparison

Here’s how the new SST-50 SMO-Deep compares the original OP version:

As you can, output levels and runtimes are pretty consistent. The difference you are seeing above is likely just sample-to-sample variation within the output and Vf bins of the SST-50 emitter. The circuit seems unchanged.

As such, here are the original runtime comparisons from my earlier review.

Potential Issues

The same issues from my earlier M3C4 review apply. The tailcap hex screws seem somewhat variable is size, and may be stripped when trying to screw down. Use extreme caution when switching to or from the clicky tailswitch.

Standby parasitic drain is still very high for the whole M3C4 series – enough to fully drain a pair of 2200mAh 18650s in less than 3 months. I recommend you store the lights with the head locked out (or with optional clicky battery carrier in the clicked off position).

The is a Med-level pre-flash when using the clicky switch with the control ring set to Moonlight or Lo. There is also a ~1sec delay in activation when using the clicky switch to turn on.

Flat-top 18650 cells may not work in the battery carrier, due to the raised plastic ring around the positive contact plate.

My new SST-50 SMO-Deep sample seems to have a defective Moonlight mode (i.e. ultra-lo and flickers slightly).

Preliminary Observations

As mentioned in my original M3C4 review, the M3-series lights are a nice incremental upgrade to he older Eagletac M2-series.

The new version of the SST-50 model – with a deeper and smooth reflector for more throw – seems to be a response to user requests. Personally, I like a floodier beam in this class of light, but many seem to prefer the option for more throw. With the bundled diffuser, I suppose everyone gets their wish! ;)

The SST-50 emitter is actually well suited for throw applications in one sense – there is no center beam void (as in the case of M-CE based lights). Of course, it is still hard to focus such a large die (i.e. you need a deep reflector). Although not quite at the same level of throw as the Thrunite Catapult V2, this new SMO-Deep version is close enough that you would only notice the difference if you had both lights directly side-by-side, shining off into the far distance. That makes this new M3C4 SST-50 one of the best throwers I've seen for this emitter. :thumbsup:

For more thoughts on this class of M3C4 lights in general, please see my earlier review.


All M3C4 lights were provided for review by Eagletac.

To follow the online discussions for this review, please see the full review thread at CPF.

Return to the master review list (at flashlightreviews.ca).

For a list of all my CPF flashlight reviews in chronological order by battery type (direct link to CPF), please see here:
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