Warning: pic heavy, as usual.
Zebralight updated their popular SC600 model to a new Mark III edition. Featuring higher output and a new emitter, let's see how it compares to the older Zebralight models (especially the SC600-II and SC62), and other recent lights in the 1x18650 class.
Manufacturer Reported Specifications:
(note: as always, these are simply what the manufacturer provides – scroll down to see my actual testing results).
- LED: Cree XHP35 Cool White (Nominal CCT 5700K). Also available with Cree XHP35 Neutral White (Nominal CCT 4500K) and Neutral White High Intensity (Nominal CCT 4500K)
- User Selectable Levels: 3 main levels (High, Medium and Low). Each main level can be programmed to one of its two sub-levels. The second sub-level of the each main levels can be further programmed to different brightness levels.
- Light Output (runtimes) for Cool White
- High: H1 1300 Lm (PID, approx 2.2 hrs) or H2 670 Lm (PID, 2.8 hrs)/360 Lm (4.3 hrs)/160 Lm (12 hrs)
- Medium: M1 70 Lm (33 hrs) or M2 32 Lm (73 hrs)/12 Lm (8 days)
- Low: L1 3.8 Lm (18 days) or L2 0.43 Lm (2.8 months)/0.06 Lm (5.1 months)/0.01 Lm (7.1 months)
- Beacon Strobe Mode: 0.2Hz Beacon at Low / 0.2Hz Beacon at H1 / 4Hz Strobe at H1 / 19Hz Strobe at H1
- Operating Voltage Range: 2.7V - 6.0V
- Battery: One 18650 size (i.e. unprotected, 65.0-65.2 mm long) 3.6-4.35V li-ion rechargeable. Batteries are not included in the package.
- Parasitic Drain: Negligible (much less than the self discharging of a battery)
- Beam Type: 80 degree spill, 10 degree hot spot
- PID thermal regulated outputs (two highest output levels) using 384 internal brightness levels and a calibrated 0.1C resolution temperature sensor
- Programmable PID thermal regulation temperature target value (existed in all lights with the PID thermal regulation feature since late 2012)
- Builtin battery protections with continuously monitored temperature, current, and voltage, plus a (2.7V) low voltage cutoff
- Battery capacity indicator (LED flashes 1-4 times, 4 short clicks to start)
- Automatic stepping down from High to Medium, and from Medium to Low when battery capacity is low
- Durable electronic soft-touch switch
- Smart user interface provides fast and easy access to all brightness levels and beacon-strobes.
- Precision machined unibody casing from premium grade aluminum bar stocks
- Proprietary heat sinking design bonds the LED board directly to the unibody aluminum casing
- Durable natural hard anodized finish (Type III Class I)
- Sealed and potted LED driver circuitry
- Tempered optical grade glass
- Orange peel textured reflector
- Battery reverse polarity protection
- Pocket clip
- Lanyard ring
- Waterproof to IPX7 (2 meters, 30 minutes)
- Dimensions: Head Diameter: 1.2 inch (30 mm), Body Diameter: 0.98 inch (25 mm), Length: 3.8 inch (96 mm)
- Weight: 2.35 oz (66 gram) without battery,
- MSRP: ~$95
Inside the standard eco-friendly Zebralight cardboard box, you fill find the light with pocket clip, spare o-rings, and manual.
From left to right: Samsung INR 20R unprotected 2000mAh; Zebralight SC600-III, SC600-II L2, SC62; Nitecore MH20; Olight S30; Thrunite Neutron 2C 2014.
All dimensions directly measured, and given with no batteries installed:
Zebralight SC600 III: Weight 64.8g, Length: 96.3mm, Width (bezel) 30.1mm
Zebralight SC600 II: Weight 79.3g, Length: 101.8mm, Width (bezel) 29.7mm
Zebralight SC600: Weight 87.2g, Length: 107.8mm, Width (bezel) 29.7mm
Zebralight SC62: Weight: 42.3g, Length: 96.5mm, Width (max, bezel): 26.1mm
Nitecore EC20: Weight: 77.1g, Length: 129.2mm, Width (bezel): 25.4mm
Nitecore P10: Weight 82.0g, Length: 135.1mm, Width (bezel): 25.5mm
Eagletac TX25C2: Weight 93.6g, Length: 120.4mm, Width (bezel): 31.6mm
Fenix PD35: Weight: 82.7g, Length: 138.1mm, Width (bezel): 25.4mm
Nitecore MH20: Weight: 85.4g, Length: 105.5mm, Width (bezel): 31.8mm
Nitecore P12: Weight: 89.7g, Length: 139.4mm, Width (bezel): 25.4mm
Olight S30R-II: Weight: 81.1g (131.1g with Olight 18650 3600mAh), Length: 117.6mm, Width (bezel): 25.0mm
Olight S30: Weight: 73.2g, Length: 116.6mm, Width (bezel): 25.0mm
Olight S20 (2013, XM-L2): Weight: 52.4g, Length: 106.5mm, Width (bezel): 23.1mm
Skilhunt DS20: Weight: 53.8g, Length: 110.0mm, Width (bezel): 24.0mm
Thrunite TN12-2014: Weight: 80.0g, Length: 140.5mm, Width (bezel): 25.4mm
The new SC600-III is even smaller than the last edition - overall length is now in keeping with the SC62.
The build of the SC600 III remains similar overall to the previous model – the main difference is the shorter battery tube now. This means that standard protected 18650 batteries CANNOT be used in the light. If you try to use anything longer than ~66mm, you are likely to dent and damage the cell.
Note as well that both the tailcap and head contact surfaces now use a series of small raised buttons, each with a spring underneath. These "pogo-pins" help ensure reliable contact (and further help save some length).
The natural-finish anodizing is similar to the last generation Zebralight (type III hard anodized). The finish seemed excellent on my sample, with none of the slight crackling I noticed on the original Mark I model. As always, labels are very minimal and small, though clearly legible against the background.
Knurling is of reasonable aggressive on the body. There are also finger wells and other body elements to help with grip, as before. Rolling is reduced due to the addition of the split-ring attachment point now, near the tail. Screw threads are anodized for tailcap lock-out.
As always with all Zebralights, the control switch is electronic and located on the head. Switch feel is similar to before, with the button slightly recessed in the opening to limit the risk of accidental activation. There are fins around the outside of head now, similar to the design of the SC5. Overall feel is similar to the previous SC600 Mark II.
Light can tailstand as before, thanks to the flat base. Pocket clip is similar to the last generation model. Note the clip remains reversible (i.e. can attach near the head or the tail, pointing in opposite directions).
The main reflector appears largely unchanged from the previous model. It is textured, to a medium-to-high orange peel finish. XHP35 cool white emitter was well centered on my sample.
The SC600-III uses a very similar interface as the last SC600 model. As always, while it may sound a little complex when first described, it is actually quite easy to use.
In general terms, on/off and mode switching is controlled by the electronic clicky switch. The main level choices are Lo – Med – Hi. There are two possible memorized outputs at each level, commonly referred to as 1 or 2 (e.g. Lo1/Lo2, Med1/Med2, Hi1/Hi2). And for each of the second levels, you can choose between 2 or 3 options. This gives you a total of 11 constant outputs to choose from. There are also 4 blinking modes.
I know that may sound confusing, but the interface is actually well laid out for simple operation. Let me walk you through everything:
By default, the light is set to come on in Hi1, Med1 or Low1. You could therefore easily use the light as a simple, straight-forward three-mode light, if you want.
To get Hi initially, do a quick single click from Off. A double-click from Off will activate in Med (after a quick flash of Hi). Press and hold (>0.5 sec) from Off to activate in Low.
As with everything on a Zebralight, it takes a bit of use to get the timings right. After about a second or so of being On, a quick click will simply turn the light off.
To advance from one mode to the next while the light is On, press and hold the switch to cycle through Lo > Med > Hi, repeatedly (you can do this directly from Off too). Release the switch to select the level. As before, a quick click turns off the light.
The sequence is actually surprising versatile - you can choose your preferred way of accessing the three main levels.
Secondary modes for each level
When On, a quick double-click at any time switches to/from the secondary mode for that level (i.e. 1 or 2). The light will memorize your choice and return to it next time you cycle or turn on at this level. The memory even lasts through battery changes.
As before, you also have a few choices as to what the secondary mode can be for each level. To enter the programming feature for any level, double-click the light 6 times rapidly. Now, every additional double-click will advance you through the three programmable options (e.g., 670 Lm, 3320 Lm, 160 Lm for Hi2). To select the mode you want as the second level, simply turn off the light once you have made your choice. When you next turn it on, that last level will have been memorized, and returned to automatically. There are now two possible Med2 levels, and three possible Lo2 and Hi2 levels to choose from.
Blinking modes are hidden away under a rapid triple-click of the switch from off. You can switch between four blinking options by double-clicking the switch once On in this state (a single click reverts you to the constant output modes). Mode sequence for the double-click is: Slow Strobe > Fast Strobe > Lo Beacon > Hi Beacon, in repeating sequence.
Quadrupule-click the switch from off, and the main emitter flashes out a relative battery strength (flashes 1-4 times, with 4 being nearly fully charged).
A new feature on the Mark III is a somewhat programmable PID setting (for how the light responds to heat on the two highest levels).
To change the PID setting, turn off the light from High1 and then turn back on to High1. Press and hold to cycle from Low to High 6 times. On the 7th (or more) cycle, release the switch to choose one of the three options:
1. release on High to add 1 degree C (up to 5 max)
2. release on Med to revert back to the factory default
3. release on Low to subtract 1 degree C (up to 5 max)
See my runtimes results later in this review for more info.
And that’s it – it is really very simple in practice, once you get used to the timings.
For more information on the overall build and user interface of my sample, please see my video overview:
As with all my videos, I recommend you have annotations turned on.
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As with my other Zebralight lights, I don't see any signs of pulse width modulation (PWM) on any the lower output modes. The light appears to be fully current controlled at all levels.
The fast strobe mode is a disorienting 18Hz tactical strobe. Pulse width is not an even 50:50 split however – the light is actually on for a shorter period each pulse than it is off (i.e., a negative deflection below signifies the on-pulse).
Slow strobe is a ~4 Hz strobe.
The beacon modes have a common frequency of one quick flash every ~5 secs. The intensity is different between the two modes (i.e., one at max, one at a lower level)
Note that these blinking mode parameters are unchanged from the previous edition Mark II.
Due to the electronic switch, all Zebralights have a constant parasitic stand-by current drain when the tailcap is connected.
I measured the original SC600 at 69.6uA, and the SC600-II L2 at a negligible 4.3uA. The new SC600-III is slightly higher at 10.5uA – which is still negligible. Even for a 2000mAh unprotected IMR/INR 18650, that would translate into over 21 years to drain a fully charged cell. This is below the self-discharge rate of Li-ions, and not a concern.
As before, you can fully break this current - and physically lock-out the light - by twisting the tailcap a quarter turn.
For white-wall beamshots below, all lights are on Max output on an 3.7V Li-ion (18650) battery. Lights are 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 SC600 Mark III has a brighter hotspot, and is brighter overall (although that is hard to see in the beamshots above). Scroll down for detailed beam output and throw measures.
All my output numbers are relative for my home-made light box setup, as described on my flashlightreviews.ca website. 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 devised a method for converting my lightbox relative output values (ROV) to estimated Lumens. See my How to convert Selfbuilt's Lightbox values to Lumens thread for more info.
Throw/Output Summary Chart:
My summary tables are reported in a manner consistent with the ANSI FL-1 standard for flashlight testing. Please see http://www.flashlightreviews.ca/FL1.htm for a discussion, and a description of all the terms used in these tables. Effective July 2012, I have updated all my Peak Intensity/Beam Distance measures with a NIST-certified Extech EA31 lightmeter (orange highlights).
As you could tell from the beamshots, max overall output has increased from the original SC600-II (which was a class leader when it came out). Peak intensity throw/beam distance is as you would expect for this light (i.e., it is still not particularly throwy).
Let's see how all the SC600 models do on my estimated lumen scale:
Overall, my lumen estimates are pretty close to Zebralights specs (as usual). The lowest output modes seem lower than the specs would suggest, but that could be the calibration of my lightbox.
As always, note my lumen estimation method is just that – an estimation based on the calibration of my lightbox. As such, don't get caught up on the absolute difference between lights or levels, as I can't guarantee absolute accuracy. Focus instead on the relative differences, as that is internally consistent across all my reviews.
Normally, my runtimes are done on standard protected 18650 cells. None of these will fit in the light – and Zebralight recommends only using unprotected cells.
Let's start with a comparison of the various modes on unprotected Samsung INR 20R (2000mAh), under my standard testing conditions (i.e., a cooling fan is used)
You can see the PID-induced step-down on the highest level – and the variable output over time. The point of a PID (Proportional-Integral-Differential) controller is that they produce a lot of very finely discriminated steps in output. This will not be apparent to you in practice (i.e., they are too subtle to see), but my lightbox can indeed detect the precise thermal regulation introduced by the PID.
At all other levels, the light is flat-stabilized, with defined step-downs only as the battery nears exhaustion.
Let's see how max output compares to the SC600-II and SC62, on both Samsung INR and Panasonic NCR18650PF (2900mAh)
As expected, the higher capacity Panasonic cells last longer. But the main difference is that the SC600-III is brighter initially than the SC600-II (which in turn was brighter than the SC62).
To explore the PID in more detail, here is a comparison of the Max, Default and Min PID settings – both with and without external cooling applied.
The first observation is that without cooling, the PID will cause a much greater drop in output after a few minutes runtime (as expected).
In terms of adjusting the PID set level, it doesn't make much of a difference overall. Certainly under cooling, there is no difference between the Default and Max PID (as you might expect). At the Min PID setting, output is slightly lower.
The main difference is under non-cooled runs (which are more representational of real life). Here, the PID setting controls how much the output drops (and thus, overall runtime). To put the traces above in perspective, the "steady-state" output of the non-cooled runs at 30 mins was about ~680 lumens for Max PID, ~620 lumens for the Default PID, and ~550 lumens for Min PID.
Like its predecessor model, the new SC600-III is 1x18650 only (i.e., it doesn't take 2xCR123A or 2xRCR). However, unlike previous models, only unprotected 18650 batteries will fit and operate in the light. Any 18650 longer than ~66mm could be dented and damaged in the light. See discussion below.
Switch timing takes a little getting used, if you aren’t already familiar with Zebralight.
As with all lights with an electronic switch, potential accidental activation is a concern, and is the standby drain. In this case, the switch is recessed to limit the risk of inadvertent activation - and the standby drain is so low as to be completely negligible. Also, you can easily lock out the light completely by a simple twist of the tailcap.
The SC600-III is a definite output upgrade to the earlier SC600-II, and tops out at over 1300 lumens from a single 18650.
However, a likely controversial change is the shortening of the battery tube, preventing standard length protected 18650s from being used. Zebralight has confirmed to me that only unprotected 18650s are supported in the SC600-III.
Apparently, a major design consideration was to accommodate future higher current-draw models in this build (e.g. the XHP50-based SC600Fd III Plus they recently added to their online google sheet). Multiple pogo pins are used to lower the resistance and the possibility of bad connections to the cells. And the Zebralight circuit can provide the same protections that integrated battery protection circuit do. They have thus decided to move to only supporting unprotected 18650s in this build (i.e., high-drain rated IMR and INR cells are expected to be used in the light).
While I can understand this reasoning, it is still problematic if you do not have the right length unprotected cells. My ~65mm Samsung INR 20R and Panasonic NCR18650PF fit and work fine. But my 67.2mm Efest 2500mAh IMR cells (with the raised positive contact button) are too long to fit inside the light – you will dent and damage the cells if you try. Frankly, anything >66.0mm is a risk in the new SC600-III.
The PID controller continues to work well in my testing – and it is interesting that they have provided a user-configurable option to adjust its baseline setting. In the case the of the SC600-III, the 5-degree up/down shift in set point resulted in +/- 10% change in steady-state non-cooled output (from the default setting). Most users probably won't bother adjusting, but it may be more relevant as higher output emitters start being used in this build (i.e. the XHP50).
Output/runtime efficiency remains top-of-class for the SC600-III. Basically, the XHP35 emitter gives greater output for the same runtime as the SC600-II L2 on max. At lower levels, output/runtime performance is largely unchanged. As before, I quite like the low battery step-down feature (on all levels), as it means you will never get stuck with no light without warning. Regulation patterns remain excellent, in my view.
A couple of Neutral White emitter options are available. My Cool White XHP35 sample actually has a somewhat warmer corona than most cool white emitters. Although the SC600-III has a slightly more focused hotspot, this is still more of a floody style of light.
At the end of the day, the new SC600-III is noticeable output update over the SC600-II. However, the move to only support unprotected 18650s is something you will need to take into account. It should be interesting to see what happens when higher output emitters are used (i.e., the upcoming XHP50 model).
SC600-III provided by Zebralight for review.