Noctigon K9.3 Review – SO MUCH GREEN

Contents

The Boring Stuff

Reddit user calmlikea3omb lent me this light for review. Here is the official product page. Below are the official specs.

What comes in the box?

This light was lent to me without a box. I can say it doesn’t include a battery or a pocket clip. Most Emisar/Noctigon lights come with a lanyard and some spare o-rings, but no manual.

Design & Construction

Build quality is excellent, as I’ve come to expect from Hank. The Anodizing is smooth and even. It’s fairly rich in color as well, much more in real life than I was able to capture on camera. All the threads you use regularly are square cut, anodized, lubed, and smooth. There aren’t any sharp edges, and it just feels high quality.

Size & Measurements

From left to right:
Emisar D4V2
Fireflies E07x Pro
Noctigon K1
Noctigon K9.3
Noctigon KR1

MeasurementMeasured (mm)
Bezel Diameter52.1
Length125.2
Switch Diameter13.2
Switch Proudness2.3
Lens Diameter49.5
Lens Thickness2.6
Body Tube Diameter (internal) 21.8
Body Tube Diameter (maximum)31
Body Tube Length84.8
Pocket Cip Slot Width3.3
Pocket Clip Slot Diameter24.5
Tailcap Diameter28.5
Tailcap Length18.0
Driver Diameter~30

Weight without battery: 204g / oz
Weight with (model) battery: 271g / oz

User Interface

K9.3 comes loaded with Anduril 2, the best flashlight user interface available at the time of writing. Itā€™s easy to use for basic operation, but allows a myriad of customization options and extra features. Itā€™s continually being improved too, and Iā€™m thrilled that itā€™s included here. Itā€™s far too complex to do a whole UI breakdown, but here are some of my favorite features:

  • Simple basic operation (1 click on/off and hold to change brightness)
  • Shortcut to moonlight
  • Momentary turbo
  • Customizable mode memory
  • Customizable minimum & maximum brightness
  • Customizable smooth or stepped brightness adjustment
  • Battery voltage readout
  • Sunset timer (dims the light over a customizable period of time)

Ultimately, my absolute favorite feature is that Anduril 2 defaults to a limited “simple UI” which is no more complicated to use than any other typical e-switch UI you’ll find on lights from Olight, Thrunite, etc. This eliminates the old argument against Anduril 1, that “it’s too complicated”, and means you can buy an Anduril 2 light for the average consumer and they won’t get stuck in some weird mode.

Modes, Brightness & Throw

Disclaimer: Lumen measurements were taken on a Texas Ace 3.5″ Lumen Tube. A candela measurement was taken with a Opple Light Master III on the highest brightness at 4.3M. Other candela figures were calculated relative to that. Runtime tests were performed with the Ceilingbounce app on my smartphone. All of these tests were performed with a fully charged Molicel P42A battery unless otherwise specified. I cannot measure moonlight directly, so moonlight readings are calculated based on the brightness relative to the next-lowest mode.

Green Lumens (@ Turn-On)Candela (@ Turn-On)Throw (meters)
Turbo (150)4,80030,500349
High (113)2,18913,912236
Medium (75)8675,511148
Low (37)1791,13767
Moonlight (1)0.10.641.59
2700K Lumens (@ Turn-On)Candela (@ Turn-On)Throw (meters)
Turbo (150)8553,400117
High (113)4661,85286
Medium (75)20581757
Low (37)5220729
Moonlight (1)0.010.040.4

Mode Spacing: Is not great. The jump from moonlight to low is huge, then the jumps between all the other modes are relatively small. I even updated to the latest firmware available at the time of writing and it’s still bad. This affects ramp speed too, so this has the same problem all of Hank’s linear drivers used to have.

Ramp speed is super fast at low levels, so fast its hard to stop at the right brightness. Ramp speed is super slow at high levels, so slow it’s hard to tell it’s even changing sometimes. Toykeeper released an update for Hank’s smaller lights recently that fixed this (and added some other minor features), but it seems those changes haven’t made it to K9.3 yet. I would expect it soon though, along with the ability to switch between instant-channel-switching and smooth-channel-ramping. That update should also allow you to run both channels together at their max brightness (if you have an emitter configuration where that makes sense).

Runtime & Currents

Green | 2700K
Green | 2700K

LVP: I did not run my tests long enough to see if the light turned off. Anduril lasts ages after low voltage stepdowns so I didn’t bother testing. However, I did observe that activation of Turbo when the cell is extremely low does shut the light off. That tells me LVP is present.

Current: Iā€™m not equipped to do extreme duration runtime tests or extremely high current measurements. I only measure the currents on low modes and I calculate the estimated runtime of those modes based on the capacity of the battery or batteries Iā€™m using for testing.

LevelCurrent @ Tailcap (milliamps)Estimated Runtime
Moonlight (Green)2.8561 days
Moonlight (2700K)1.045167 days
Standby (aux high)1.061165 days
Standby (aux low)0.0905.3 years
Standby (aux off)0.0519.4 years

Note: Aux LED’s were set to green for current testing.

Driver & Regulation

K9.3 uses a two-channel driver. Channel 1 is connected to the main set of 9 LED’s (W1 greens in this case). It’s 9A+FET construction, so from 0 to 9 amps it’s driven linearly, and above that it’s driven by the FET with PWM to regulate brightness. Channel 2 is connected to the secondary set of 3 LED’s (SST20 2700K’s in this case). It’s a 5A linear construction, so it’s fully regulated but can’t get nearly as bright as the main channel. Use the slider below to compare the regulation and brightness of both channels!

Green | 2700K

Regulation is typical of Hank’s linear drivers, and that’s good. Turbo drops with cell voltage, as is expected from FET drive. All other modes can reach their peak brightness until the battery is nearly empty.

Note: All regulation measurements are taken at turn-on so they do not reflect any thermal or low voltage stepdowns that may occur.

Thermal regulation: Anduril has the best thermal regulation I’ve seen and it works great here. Cooling the light by holding it or blowing cool air over it will result in higher output. You can also adjust the thermal limit as you see fit to keep it nice and cool, or let it run as bright as it can.

Emitter & Beam

K9.3 is available with a huge variety of emitter options. This particular sample has a pretty unique set. Channel 1 is Osram W1 greens, and channel 2 is SST20 2700K’s. Even more unique is that this sample has elliptical optics installed over the W1’s so the beam is a wide ellipse instead of a circle. It’s very weird and very cool. The 2700K channel is round, floody, and very warm.

Green | 2700K

Just for fun, here’s how it looks with the elliptical optics all facing a different direction.

When bouncing the light around in my white photo booth, I got the following measurements from my Opple Light Master III. W1 greens measured in with a RA (CRI) of 70 which surprised me, because I expected it to be much lower. You can see it when using them too. Green is the dominant color but all the other colors are there too, really. Warm White measured in at 2700K and 98 CRI. Impressive!

Green | 2700K
Green | 2700K

Outdoors, the green spreads out wide without wasting too much light up into the sky or down right at your feet. This elliptical beam would be perfect for a bike light. I can’t think of any other practical use cases for it though.

Aux LED’s

There are so many. The aux LED’s on K9.3 are just gorgeous.

Moonlight & Tint Comparison from left to right:
Emisar D4SV2 2-Channel | Samsung LH351D 5000K
Noctigon KR4 2-channel | Nichia 219B SW27/SW45K mix
Noctigon K9.3
Emisar D4V2 | SST20 4000K
Fireflies E07x Pro | SST20 4000K

Green | 2700K

Yes it is on in the second photo. I calculate the green channel moonlight at 0.1 lumen, and the warm white channel moonlight at 0.01 lumen. Yeah, it’s that dim. It’s basically useless, and it’s incredible.

It does take ages to turn on though: about 2 seconds from when I depress the switch to when the emitters are fully powered on. Toykeeper has fixed this problem in Hank’s smaller lights with a firmware update, by adding a customizable jump start. At the time of writing, that improvement has not made it to the latest K9.3 firmware.

Switch

K9.3 uses a white, backlit, electronic, side switch. The backlighting isn’t RGB, but you can choose the color when you order. The owner of this light chose green, of course. It’s a fine switch and I love that it’s backlit.

Carry & Ergonomics

In-hand K9.3 is pretty nice. The button is right where my thumb naturally wants to rest. I can click the button comfortably with the tip or knuckle of my thumb, but using the pad requires too much force. There are no hotspots when holding it, and it feels dense and high quality. The flats in the cooling fins are super nice. The ergonomics are excellent.

If I had to critique something, I’d say body tube feels a little narrow and short for my large hands. I would love to see a 26800 body tube for this and Noctigon K1 released in the future. There’s plenty of space in the threads since the 21700 tube flares out so much.

My sample was lent to me without a box or accessories, but I don’t think any carry methods are included besides a basic lanyard. The head is too wide to fit into a pants pocket, but I think a basic clip would have been nice to have, especially for the high asking price. If you want to use it in a belt holster, I found it fits great in a Convoy C8 Holster.

Batteries & Charging

K9.3’s body tube is identical to the one from K1, so this section is mostly just copied from my K1 review.

K9.3 uses an unprotected, flat top, 21700 battery. You canā€™t buy one with the light from the manufacturer, so youā€™ll have to buy a battery separately. For the Nichia emitter options on channel 1, a 5000mah cell with a 10A discharge rating will be fine. But for all other options you’ll want to use a higher discharge cell if you want maximum output. Iā€™m using a Molicel P42A for my testing. 18650ā€™s will work in a pinch, even unprotected flat tops.

K9.3 includes one of the best integrated charging solutions Iā€™ve seen. The charging port is built into the threads of the body tube, so itā€™s sealed against water and dirt by the o-ring. This is a lot more reliable at keeping particulates out than the cheap rubber flap port covers used on most lights with integrated charging. It also has no problem with over-sized USB-C plugs because itā€™s not set down into some rubber flap cavity.

C-to-C charging and A-to-C charging both work fine. Charging a P42A takes about two and a half hours. During charging, the end of the body tube will glow red. When charging is complete, it will glow green. Itā€™s worth noting that the contacts on the end of the battery tube connect directly to the cell as far as I can tell, so donā€™t just toss the battery tube in a pocket with your keys, as that will likely cause a short and lead to some dangerous problems.

In the future, I do think it would be cool for Hank to offer a 26800 body tube for K9.3 (and K1, by extension). There’s plenty of width in the threads to fit the larger tube.

My Complaints

I’ve had two problems with this light since its release: the beam and the price.

The Beam: K9.3 has two floody channels, one brighter than the other. That’s fine, but what I really want is one flood channel and one throw channel. I think this light would have been much better if one channel was for bright flood, and one was for long throw. Two different channels in the same light with the same beam profile just isn’t very useful to me except for tint ramping. Even then, K9.3’s channels are highly mismatched in brightness so tint ramping won’t look right.

This bugs me so much that I went and designed a Noctigon K12.1 concept and sent it to Hank. He’s not going to produce it, but he told me he is working on something similar (flood & throw channels, 3×18650 batteries).

Price: This light starts at about $120, and can go up from there based on emitter selection. It may be advertised as “two flashlights in one” but it’s not. It’s one body, battery, switch, etc. The only thing that’s doubled is the number of channels, so the price shouldn’t be double Hank’s other lights.

Fortunately, the light’s been out for quite awhile and Hank as recently released new versions of most of his other lights with the same two channel feature as K9.3, and they start at around $60.

Update: Hank recently released Noctigon DM1.12 which is exactly the light I wanted K9.3 to be. It’s just like my design with 12 flood LED’s around a center throw optic, with a side switch and an (optional) 26800 tube and tailcap. Buy this instead!

Competition

Here are some lights in the same class and how they compare. There really aren’t many lights that do this whole two-channel thing to the same level that K9.3 does, especially with all those emitter options.

Emisar D4SV2 2-Channel: Smaller, bigger battery (especially with the 26800 tube), no integrated charging, not as bright, way more throw, narrower beam, magnetic tailcap, half the price

Wurkkos WK30: Smaller, bigger battery, micro-usb charging, not as bright, only one emitter configuration but three different channels (white, red, UV), inferior UI, one third the price

This section is not comprehensive. If I didn’t include a particular light here, it doesn’t mean it’s bad or doesn’t deserve to be here. I simply cannot list every possible competitor.

Update: Hank recently released Noctigon DM1.12 which is exactly the light I wanted K9.3 to be. It’s just like my design with 12 flood LED’s around a center throw optic, with a side switch and an (optional) 26800 tube and tailcap. Buy this instead!

Conclusion

K9.3 is an excellent light, but the price has been under-cut by newer lights. Unless you must have USB-C charging, twelve LED’s, elliptical optics, or a 21700 battery, you should buy one of Hank’s other 2 channel lights instead.

Thanks to calmlikea3omb for lending me this light for review!

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