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Now I’ve reached the last of this series of four Streamlight reviews. Having started with the Sidewinder, I’m going to wrap the series up with its progeny, the Sidewinder Compact II.

Following feedback on the original Sidewinder, a compact version was produced, this was then improved on resulting in the Compact II

The Sidewinder Compact II has two different versions, the Military and Aviation. On test is the Military version.





Initial Impressions:

The Sidewinder Compact II shares the same head as the Sidewinder, but is much smaller; really living up to its name.

Like the Sidewinder, the Sidewinder Compact II uses four different emitters to give the user 20 different colour/brightness output options in one light.

Being small and made of nylon, the Compact II feels very light and handles well even though it is a strange shape.

One of its special features is its flexibility on choice of battery used to power it. Officially specified as CR123 and AA alkaline or lithium, it turned out to be even more flexible than this.



What is in the box:

The Sidewinder Compact II comes in a plain cardboard box.





It is supplied with an instruction manual Streamlight CR123 and helmet mount.




Also supplied for review is the Headlight strap mount





Taking a closer look and looking inside:

Taking a look all around the Compact II

The front view showing the polycarbonate lens and the four emitters



Looking closer at the emitters with the 5mm LEDs being red, IR and blue from left to right.



And even closer at the Streamlight C4 emitter



The clip is sturdy, and made of coated steel. It allows for belt, MOLLE, head-strap, and with the ACH mount, helmet mounting options. The clip rotates around the battery tube allowing its position to be adjusted when helmet, or head-strap mounted.



Looking down onto the switch which has the different LEDs marked on the rubber dome. The one that is facing forward is the colour it outputs, so here it is shown with the White LED active.



The Compact II’s tail-cap is plastic to match the rest of the light and is hinged by a black plastic retainer.



The Military model has an IR safe indication on the side. If you position the raised part of the selection ring to point at the IR safe position, the Blue LED is selected which will not output any IR.



Unscrewing the cap allows you to see the spring fitted in the cap, and the metal contact ring around the end of the battery tube



Looking inside the tube and the secret of the Compact II’s versatility is revealed. The battery tube has a special positive contact which consists of a long spring with a sliding plastic plate on top. The plate has a hole in the centre to locate the positive terminal of the battery and will move down inside the tube when the longer AA cell is used (rather than a CR123).



The rear of the helmet mount has a metal clip secured with two screws that firmly fix this to a modern military helmet.





Modes and User Interface:

Just like the Sidewinder, the Compact II is “20 flashlights in one” referring to the set of five modes which are repeated for each of the four emitters.

Each emitter has Max, High, Medium, Low and Flashing modes available. For the Military model on review, the Compact II turns on in Low and has red, IR and blue coloured LEDs.

Here the multiple LEDs are all shown on at once using a triple exposure for the photo, changing mode between exposures. In the left hand photo, the IR LED (between the red and blue LEDs) just registers with the camera.



To turn on, click the rubber dome soft click switch, and to change mode the rubber dome switch is held down to cycle through the modes and follows the sequence Low -> Medium -> High -> Max -> High -> Medium -> …… so unlike many lights it ramps up and down and does not jump straight from Max to low.

A quick double click enters the flashing mode which is set at Max output.

Surrounding the switch is a selector ring for the emitter. This must be pulled up, rotated and dropped back down to lock in the selection. The emitter can be changed while the light is in any mode without changing the mode. Two hands are needed to change the emitter and the selector ring has a raised section to allow for tactile LED changes.



Batteries and output:

Streamlight specifically designed the Compact II to take CR123 and AA following feedback from users of the original Compact. What they have achieved is even more flexibility than was intended.

Only CR123, alkaline or lithium AAs are specified. However after testing I found that the Compact II works with CR123, RCR123 (as long as Max output is not used) the three types of AA cell, Ni-Mh, Alkaline and Lithium and the same three types of AAA!

Thanks to the clever battery tube design, the Compact II accommodates CR123, AA and AAA size cells and has worked (with some limitations) with all types of all these sizes. That is three different sizes and a total of 8 different batteries that can be used.

Not only do you get all this choice in battery size and type, but you also get a ‘battery vampire’ due to the Compact II’s red LED and the fact it turns on in low. An AA battery that will no longer light the white led will give a couple of hours light with the red LED.

Apart from the RCR123, which gave a potentially damaging turbo boost to the max output, the output figures across all types of cell were very consistent.

Personally I would only use the RCR123 as a last resort, and if using it avoid the Max output (which is easy as it turns on in low), but it is usable.

To measure actual output, I built an integrating sphere. The sensor is a photo-diode restricted to visible light only (so Infra-Red and Ultra-Violet will not register). This was chosen as our eyes can only use the visible wavelengths of light so this is generally the only useful output. The integrating sphere was calibrated using 12 different reference sources and taking an average of the factor used to convert the measured voltage output to Lumens. Output figures are quoted as ANSI lumens where the measurement is made 30s after turning on the specified output level. Initial figures when first switching on are always higher, but all quoted measurements are ANSI.



Please note, all quoted lumen figures are from a DIY integrating sphere, and although every effort is made to give as accurate a result as possible, they should be taken as an estimate only. The results can be used to compare outputs in this review and others I have published.

The main set of figures are for the CR123, and only where the output differs from this baseline are the extra output figures included.

Sidewinder – Compact II MilitaryI.S. measured ANSI output LumensPWM frequency (Hz)CR123 White - Low5N/ACR123 White - Med15N/ACR123 White - High23N/ACR123 White - Max60N/AAA White - Max53N/ARCR White - Max166N/ARCR White - High31N/A

Output is regulated and as the batteries become depleted, the output drops a level. Once the lowest level is reached, eventually the Compact II will switch itself off. After a period of recovery, you will typically be able to squeeze a little more light out.

As the coloured LEDs run at much lower outputs, once the Compact II can no longer output white light, you can switch to a coloured LED and run for several hours longer.

Being a soft click button, there is parasitic drain to be considered as the internal circuit is kept powered. The Compact II is unfortunately not as good as the Sidewinder in this regard and each type of cell had a different parasitic drain.

Cell typeMeasured DrainTime to drain cellCR12348.3uA3.91 YearsAA Ni-Mh0.12mA1.9 YearsAA Lithium0.07mA4.74 YearsAA Alkaline0.1mA3.08 Years



In The Lab

In an attempt to quantify the actual beam profile I developed the following test. There are probably many flaws in my method, but it is simple and easy to carry out and seems to provide a good enough comparison.

The method used was to support the light 1m off the floor and 1m from a wall, with a tape measure on the wall. The zero of the scale is placed in the centre of the hotspot and a lux meter is then positioned at points along the scale, with the measurements recorded. Beam shots are often taken with the light shining on a flat white wall, so this method is simply measuring the actual intensity across the beam on a flat surface, not the spherical light emission.

The results are then plotted on a graph.

For the best throw you want to see a sharp peak with less of the distracting spill. For the best flood light the trace should be pretty flat.

The Compact II’s beam profile is shown here compared to the other Streamlight lights I have on review. The Compact II has a brighter wider hotspot than its predecessor the Sidewinder.



Taking this a little further, I calculated an approximate factor to apply to the lux measurements, as each measurement gets further from the centre of the beam, it corresponds to a larger area onto which the light is falling. It seems to me that this should also be taken into consideration, so I applied these area corrections and came up with this odd looking graph.

The key quantity here is the area under the graph line. This should correspond to the total light output.

However, it has slightly less light in the spill area than the Sidewinder.





The beam

As shown by the previous beam profile graphs, the Compact II has a brighter wider hotspot than the Sidewinder but with a slightly dimer spill.

The beamshot is exposed to give an impression of the beam’s brightness to the naked eye.



You can see some shaping of the spill due to the square front of the Compact II’s casing.

The Compact II’s beam is much smoother than the Sidewinder’s beam, probably due to the different choice of emitter.

Output from the 5mm LEDs is typical as far as beam quality goes.



What it is really like to use…



Just as with the Sidewinder, the Compact II’s recessed soft-click switch is deep enough not to activate accidentally, but not so deep as to make it difficult to operate.

Ergonomics are slightly odd but you can hold the Compact II in a variety of ways so that you can operate the switch with a finger or thumb.

The maximum output is not that high, at a measured 60 lumens, but this is perfectly sufficient for dark environments up to many meters away. It may not be enough in high contrast situations such as peering into an engine bay on a sunny day, but when not fighting another source of light, is a perfectly reasonable output level.

The Compact II is small enough to make it good to use regularly as a head light. The metal clip, locks into the plastic mount of the head strap, with the clip’s angle adjustment allowing you the point the light where you want it.



The single strap is secure enough as the Compact II is lightweight and makes this a true all rounder.




Being small and light, I’ve found the Compact II accompanies me virtually unnoticed, and the unusual shape lends itself to standing in several different ways, or clipping onto a pocket, belt or the head-strap

The Military model on test comes on with the low output level. For many this is the preferred choice as you can always turn it up as required.

Having a choice of colours, for lower level specialist lighting needs is very useful. Around animals, or if going hunting, the non-white outputs can be less startling and better with dark adapted eyes.

I don’t have any IR related cameras or night vision devices, so can’t comment on the usefulness of the IR output as I have no need of it. I would have preferred this to be a green LED instead of the IR one.

Again, like the Sidewinder it is possible to operate the light using the tactile features, and it is good to know that if necessary, I could change the battery, and select one of the lower output coloured LEDs and IR safe mode all by feel alone.



The Compact II is a uniquely flexible light, with 20 different output modes and being able to run on three different sizes and 8 different types of battery! With this light you should be able to scrounge a replacement battery from somewhere when you really need to.

It may not have the highest output, or use the latest LEDs, but I’ve found the Sidewinder Compact II to be so useful and versatile I’m not sure if it should go in my bug-out-bag (thanks to being a great choice if having to scrounge a replacement battery) or in the tool box, in the car, by the bed or somewhere else close at hand.




Test sample provided for review by Streamlight.

I’ll update post 2 of this thread once I have some more comments to add....