Surefire UB3T Invictus (XM-L, 3xCR123A) Review: BEAMSHOTS, RUNTIMES, ANALYSIS + more!

Originally posted: September 10, 2011
Last revised: September 12, 2011

Warning: a LOT more pic heavy than usual.

Out of the night that covers me,
Black as the pit from pole to pole,
I thank whatever gods may be
For my unconquerable soul.

Invictus, by W.E. Henley.

Although I’ve included runtime data from some of my personal Surefire lights in other reviews, this is the first sponsored full review that I have done of a Surefire light. And this is certainly a whopper to begin with - the UB3T "Invictus".

Manufacturer's Specifications:

The light is securely packaged, and comes with a removable lanyard ring (attached), good quality wrist lanyard and clip, manual, three Surefire-branded CR123As (inside the light) and various product inserts. As typical on Surefire lights, there is no holster (although various after-market solutions are available).

Here are some close-ups of the box.

From left to right: Surefire CR123A, UB3T Invictus, JetBeam M1X V2 (with extender), Olight M31 (no extender), Thrunite Catapult V3, JetBeam BC40.

All dimensions are given with no batteries installed:

Surefire UB3T: Weight: 311.1g, Length 229mm, Width (bezel): 63.1 mm
Skilhunt X3 (no extender): Weight: 251.8g, Length: 193mm, Width (bezel): 44.1mm
Olight M31 (no extender): Weight: 258.1g, Length 209mm, Width (bezel): 62.3mm
Lumintop TD-15X (no extender): Weight 150.3g, Length 147.3mm, Width (bezel) 37.8mm
JetBeam BC40: Weight: 226.3g, Length: 224mm, Width (bezel): 48.5mm
Thrunite Catapult V3: Weight: 434.8g, Length: 254mm, Width (bezel) 58.0mm, Width (tailcap) 35.1mm.

The UB3T is definitely longer and heavier than other 3xCR123A lights (e.g. the X3, M31 and TD-15X listed above). It is closer to a compact 4xCR123A light (e.g. BC40).

The overall body design of the UB3T Invictus is similar to the classic Surefire M4 Devastator, although modernized for the new control ring and LED and optic.

The body is a matte black finish with bright white labels, similar to Surefire E1B Backup, but with a more stylized font. Although the body is smooth, I find the anodizing gives it a somewhat "grippy" feel. I noticed something similar on the Armytek Predator (i.e. anodizing almost feels like it is slightly rubberized). The net effect is fairly good grip, especially with the grip ring and other design elements.

Screw threads are square-cut, and the light can be locked out at the tailcap. I believe Surefire now uses a clear "chemfilm" for tailcap lockout, as opposed to traditional anodizing.

Tailswitch is not a clicky switch – rather, it a two-stage screw/press-style tactical switch. Something similar is used on the Surefire L2-series lights, but this switch is a lot deeper and has a lot more screw threads. The main difference here is that the "Lo" state (i.e., partially connected) actually allows you to use all the output modes on the control ring. As with the L2-series lights, fully tighten for Max.

There is a substantial spring in the head.

The control ring has a solid feel, and is labeled (clockwise, holding the light in your hand pointed away from you): OFF > SOS > MIN > (bar stage 3) > (bar stage 4) > (bar stage 5) > (bar stage 6) > (bar stage 7) > (bar stage 8) > (bar stage 9) > MAX > STROBE.

There are definite detents at all levels, and the control ring feels firm and reasonably stiff. I believe the ring uses the Hall effect with magnetic sensors to switch modes, but have not directly tested this. Note the additional OFF mode on the ring - no light is produced here, no matter what state the tailcap is in.

There is a battery indicator LED over the SOS label. More on this later.

Of course, one of the most distinctive aspects of the light is the head – instead of a standard reflector, the UB3T uses a distinctive large TIR (total internal reflector) optic:

The UB3T is presumed to use a Cree XM-L emitter (obviously hard to see under that optic to confirm ). The optic is most interesting – it has at least two clearly demarcated concentric ring areas. As with all optics, I would expect excellent throw with little-to-no side-spill (i.e. this is not like a reflector). Scroll down to my beamshots section later in this review for a comparison.

Before I move on, I also picked up the standard Surefire FM24 2.5-inch diffuser cap. This allows you rapidly switch between a diffused state and max throw:

UPDATE SEPT 12, 2011: I have been advised that the FM24 diffuser has been discontinued by Surefire. So you may have trouble finding one (a few Canadian dealers may still have inventory, at the the time of this writing). A pity, as it does a great job of diffusing the UB3T's beam, as you will see later in this review.

Beamshots will also include the effect of the diffuser.

Video Overview

NEW: Normally at this point in the review, I like to show the beamshots. But I’m trying something new - video reviews showing both the basic build and user interface. Beamshots will follow after the user interface and circuit discussion.

Because there is a lot to say about this light, I have broken the video into two components, as described below.

Part I - Build, Beam and Circuit Performance

Part II - Control Ring and Battery Indicator

Videos were recorded in 720p HD, but YouTube defaults to 360p. Once the video is running, you can click on the 360p icon in the lower right-hand corner, and select the higher 480p or 720p options, or even run full-screen.

User Interface

Output Control

Simply put, you partially tighten the tailcap to access all the output modes of the control ring, fully tighten to activate Max output.

When the tailcap is partially screwed on (i.e. in your desired output mode as set by the ring), you can press the tailcap button to jump to momentary Max. When you release the button, the light returns to your set level.

If you unscrew the tailcap just enough to completely turn off the light, a soft-press will give you your set level, and a harder press will give you Max output.

Unscrew the tailcap further, and a press will only give you the set level mode.

Unscrew even further, and a press will not activate the light (i.e. the light is locked out). Don’t worry – there are a LOT of screw threads left, even when the light is locked out.

If that is not clear, I recommend you refer back to the videos above for a more thorough discussion of the interface.

Standby Current

The OFF state of the control ring prevents any light from coming out (even when the tailcap is fully tightened). Given the design of the light, this clearly requires some sort of stand-by/parasitic current (i.e., in this mode only, and only when the tailswitch is tightened past the lock out).

Measuring tailcap current draw is a little tricky, since without the tailcap in place, connecting the batteries to the body tube gives you Max output (which I measured at 1.6A on 3xCR123A). I can’t measure any of the other output modes, since you need to have the tailcap partially connected for that.

But I can measure the standby current in the Off mode. My DMM oscillated between 66uA, 76uA, and 86uA in a regular pattern (i.e. about ~1 sec at each current, repeating). If I take the average 76uA, that means for three CR123A batteries in series (1500mAh capacity), you would get 2.25 years before depleting the cells.

This is not a worry, but as always, you can easily break this low current by loosening the tailcap to lock-out the light.


Ok, this is going to take some explaining.

Let’s start with Strobe:

The UB3T uses a 8.8 Hz tactical strobe mode. But wait – what are those extra trains of spikes every ~350 msecs? That’s where things get interesting. Let us start at the lowest constant output level and work our way up.

Min output, 2 lumens (stage 3 on the ring):

The UB3T clearly shows a PWM signal, at just over 2 kHz. This is considered to be a not-visually-detectable PWM frequency, although you can just barely see it if you shine the light at rapidly moving fan blades. In practical terms, you won’t notice it.

8 lumens (stage 4 on the ring):

Still showing 2 kHz PWM. Perfectly acceptable.

15 lumens (stage 5 on the ring):

There is a very weak signal showing up at 126 Hz now. This would be plainly visible if it were actual PWM, but I can see no evidence of PWM by eye. Similarly, shinning the light on a moving fan shows no evidence of PWM.

But it gets more interesting, as there are other repeating circuit blips at different timescales now:

As you can see above, there are triplet signals (31 Hz apart), that show up every 150 msecs or so (i.e. 6.6 Hz). Whatever these circuit blips are, they are absolutely not visible by eye, or by shinning on a fan.

30 lumens (stage 6 on the ring):

Ok, this signal is VERY visible now. At this level, there is a very definite PWM-like effect going on, which I would say visually matches up with the 126 Hz signal shown above.

Note that the 126 Hz signal pattern looks rather unusual at this level (i.e., not a clear single spike). This may be contributing the visible PWM-like effect.

Also, there are still additional circuit signals present at lower frequencies. Let me skip ahead to 160 lumens (stage 8 on the ring) to show you some clear examples:

As you can see, you still get the main 126 Hz signal (although again, it doesn’t look like any PWM trace that I’ve seen before). There are also other repeating signals at 6.2 Hz and 0.54 Hz. These sorts of multiple signals are present all the way up to and including the Max mode.

But oddly enough, the PWM-like effect diminishes as you increase in output beyond the 30 lumen mode (where it is the most visible). So even though this 126 Hz signal persists, it becomes less and less noticeable with higher outputs.

Here is a summary of what I actually see by eye:
I honestly don’t know what to make of all that, but my best guess is the extra signals are involved in helping filter the PWM effect, making it less visually noticeable. The take home message is that only the 30 lumen mode is annoying, for those of us who are sensitive to PWM.

I have tried to capture all of the above info in a visual way in Part I of my video review. Check it out to hear additional commentary, and see exactly what the effect looks like on fan blades.

Battery Indicator

Many battery indicators simply provide a static indicator of relative battery capacity. That doesn’t tell you much about what runtime to expect at different outputs modes (and may not even be very inaccurate to start with ).

In this case, I am happy to report the UB3T’s battery indicator is contextual – that is, it tells you how much relative battery life you should expect at your current output level.

So if the light is green, you can rest assured you have a lot of runtime left at the current level. Orange indicates you should switch down to a lower level to maintain decent runtime (i.e. the light goes green again, as you switch down in output). Red means you are at imminent risk of the batteries dying on you, and need to switch down immediately.

Note that at the higher output levels, output will have begun decreasing by the time you are in the orange warning level. At such, red warning is almost superfluous at higher outputs (i.e., you can tell from the greatly reduced output before it even turns red).


And now the part you’ve all been waiting for.

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.

As expected, the UB3T’s TIR optic gives you a very focused beam, with something of a square-shaped hotspot. As with all optics, there is very little side spill. Throw is quite good - certainly in the same class as my Thrunite Catapult V3 (although the hotspot/corona looks quite different). Scroll down to my outdoor 100-yard beamshots for a greater comparison.

But first, here’s how things look with the FM24 diffuser:

I have now done 100-yard outdoor beamshots, in the style of my earlier 100-yard round-up reviews:

As you can tell, the UB3T has the perfect beam if you plan to impersonate a UFO landing spotlight.

Seriously, it is clearly designed for maximum throw with little spill. The main application would be for when you wanted as little blowback as possible from surrounding near field illumination.

In real life, it seemed to me that the UB3T threw further than the Catapult. But it is hard to tell, since the UB3T has a broad (yet even) central hotspot, whereas the Catapult has a traditional bright center hotspot with much dimmer corona. Still, these beamshots match my visual experience more than what my throw @ 1m numbers indicate in the table below (actually measured at @ 5 meter, and converted back to 1 meter – see below for a discussion).

The FM24 diffuser does a nice job of turning this narrow spotlight into a wide-range illuminator.

Testing Method:

All my output numbers are relative for my home-made light box setup, a la Quickbeam's 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 for a description of the terms used in these tables.

The UB3T clearly outclasses 2xCR123A-type lights, both for throw and overall output.

A better comparison is thus to the high-output class of 2x18650 lights:

A word about the throw values. Consistent with FL-1, all my throw values are based on actual measurements at 5 meters, and converted back to 1 meter. Normally, 5 meters is far enough to allow a reflectored beam to fully converge. But with the TIR optic on the UB3T, I was getting a lot of variability in light meter readings in the hotspot at this distance - from 1300 to 1600 lux (i.e. 32,500 to 40,000 lux @ 1m equivalent). So, I have given the max as ~40,000 lux @1m in the table above.

See my outdoor 100-yard beamshots earlier in this review for a picture comparison, which I think gives a better feel for what the beams really look like.

Output spec is believable at 800 FL-1 lumens.

Output/Runtime Comparison:

Max output is higher than any of my 2xCR123A lights, and runtime is considerably increased at all levels (thanks to the extra CR123A).

Note that Max = 800 lumen mode, S9 = 325 lumen mode, and S8 = 160 lumen mode, in all graphs.

Max output is comparable to my other heavily-driven high-output XM-L lights (in fact, a bit higher initially). Overall efficiency seems excellent at all levels tested. Regulation is perfectly flat at all levels below Max.

Potential Issues

The light has a visible PWM-like effect on the 30 lumen and higher output modes, although it is really only noticeable or distracting at the actual 30 lumen level.

Like most Surefire lights, the UB3T is not rated for Li-ion rechargeables. 2x 3.7V Li-ion should work safely in the light (e.g. 17500), but I have not tested this. Note the body tube is quite narrow, so I am not sure if protected 17500 would fit in the light (18500 certainly won’t). And note that 3x 3.7V RCR would likely blow the circuit.

SOS and Strobe are located at opposite ends of the ring, meaning you need to go through SOS to reach the ring’s OFF mode (and there is nothing between Max output and Strobe). You can avoid seeing these modes by controlling on/off at the tailcap, but it does seem a peculiar arrangement on the control ring to me.

The light lacks knurling as such, although the various build elements do help with grip. I found overall grip reasonable.

While the battery indicator is contextual for a given mode, I find there is relatively little battery life left at the higher output modes by the time the indicator turns orange (i.e., decreased output can be observed long before the indicator turns red in these modes).

There are a lot of screw threads on the tailcap, requiring you to turn more times than typical to lock-out the light.

Preliminary Observations

The UB3T in an impressive light, sporting a number of interesting innovations.

The dual-control tailcap is an update from the two-stage Surefire L2 tailcap, here allowing you to access the ring-controlled output level in the partially-tightened state. As always, fully tighten for Max output. This is my preferred "tactical" tailcap design, as it allows constant-output (twisty) or momentary (press) – including access to multiple levels directly from Off.

The control ring has a good number of outputs, clearly labeled on the body of the light. Feel of the ring is good, with definite detents (although note it can be hard to turn single-handed while holding the light). Personally, I would prefer to see flashing modes bundled together (preferably with a Standby/Off mode between them and the constant output modes). But thanks to the dual-control tailcap, you can easily skip seeing the flashing modes (i.e. just turn off-on by the tailcap).

The TIR optic is one of the largest I’ve seen, and one of the most visually distinctive. It works very well to throw an even (if somewhat square) center beam a good distance. As with all optics, there is relatively little side-spill with the light. This can be advantageous in crowded environments, if you want to minimize light reflections from the surrounding area. And of course, the optional 2.5-inch Surefire diffuser does a great job of turning the UB3T into a flood light.

The relative battery-life indicator is good, showing contextual information for each output mode. This is far more useful than typical indicators.

Max output and throw are top-of-class for a XM-L light. Runtime and circuit regulation patterns are excellent at all levels tested. My only disappointment with the circuit is the clearly visible PWM-like effect at the 30 lumens level (and to a lesser extent at the immediately higher outputs). Still, there are plenty of other output levels to choose from, and I can easily forgo this 30 lumen one.

Overall build quality is excellent. Hand feel is good, and the light isn’t as front heavy as I expected. Grip is acceptable, although you may want to consider carrying with the wrist lanyard in place.

Given the size and hefty price tag, this light clearly isn’t meant to be your every-day carry. Although the well-executed control ring and dual-function tailcap are probably the features that attract the most initial attention, at the end of the day I believe it is the beam pattern that really distinguishes this light. With its heavily-focused narrow beam (with minimal spill), the UB3T will likely appeal to those seeking a high-output light that can punch far into the distance.


Surefire UB3T provided by Battery Junction for review.

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

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Page last updated on September 7, 2011 - selfbuilt (at) sliderule (dot) ca (replace the "at" and "dot" labels with the appropriate symbol for e-mail)
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