[Review] Noctigon KR1 SST-40 with detail on strobe modes.

19 posts / 0 new
Last post
stephenk
stephenk's picture
Offline
Last seen: 21 hours 16 min ago
Joined: 01/30/2016 - 05:09
Posts: 2409
Location: Australia
[Review] Noctigon KR1 SST-40 with detail on strobe modes.

I’ve recently published my review of the Noctigion KR1 SST-40.
This is written primarily for light painting photographers, so the review takes a good look at the Noctigon KR1 and Anduril’s strobe modes including photos of fastest and slowest frequencies.
Note the huge “real world” brightness difference between tactical mode and strobe mode.
Review here >> https://www.stephenknightphotography.com/post/flashlight-review-noctigon-kr1

Lumen9000
Lumen9000's picture
Offline
Last seen: 2 months 1 week ago
Joined: 09/02/2021 - 09:14
Posts: 291
Location: Sweden

Cool! But isn’t it the S+F+T-40?

stephenk
stephenk's picture
Offline
Last seen: 21 hours 16 min ago
Joined: 01/30/2016 - 05:09
Posts: 2409
Location: Australia

Lumen9000 wrote:
Cool! But isn’t it the S+F+T-40?

No, this review is of the SST-40. I don’t think the SFT-40 is available in the KR1 (maybe via special order).
Lumen9000
Lumen9000's picture
Offline
Last seen: 2 months 1 week ago
Joined: 09/02/2021 - 09:14
Posts: 291
Location: Sweden

stephenk wrote:
Lumen9000 wrote:
Cool! But isn’t it the S+F+T-40?

No, this review is of the SST-40. I don’t think the SFT-40 is available in the KR1 (maybe via special order).

So, you are saying I read that wrong multiple times yesterday?! Yes I did! Thank you for pointing that out good sir!

The choice is much easier then! But still lacks USB-charging so I hold on till they get that sorted out.

stephenk
stephenk's picture
Offline
Last seen: 21 hours 16 min ago
Joined: 01/30/2016 - 05:09
Posts: 2409
Location: Australia

Lumen9000 wrote:
stephenk wrote:
Lumen9000 wrote:
Cool! But isn’t it the S+F+T-40?

No, this review is of the SST-40. I don’t think the SFT-40 is available in the KR1 (maybe via special order).

So, you are saying I read that wrong multiple times yesterday?! Yes I did! Thank you for pointing that out good sir!

The choice is much easier then! But still lacks USB-charging so I hold on till they get that sorted out.


I don’t personally see USB charging as a deal breaker on enthusiast grade lights. I much prefer to keep an eye on voltage, capacity, and IR by using a dedicated analysing charger such as the Vapcell S4 Plus.
For consumer orientated flashlights, I would mark down a product in a review if it lacked USB charging as the average person buying one is unlikely to be knowledgeable Li-ion batteries.
Lumen9000
Lumen9000's picture
Offline
Last seen: 2 months 1 week ago
Joined: 09/02/2021 - 09:14
Posts: 291
Location: Sweden

stephenk wrote:
Lumen9000 wrote:
stephenk wrote:
Lumen9000 wrote:
Cool! But isn’t it the S+F+T-40?

No, this review is of the SST-40. I don’t think the SFT-40 is available in the KR1 (maybe via special order).

So, you are saying I read that wrong multiple times yesterday?! Yes I did! Thank you for pointing that out good sir!

The choice is much easier then! But still lacks USB-charging so I hold on till they get that sorted out.


I don’t personally see USB charging as a deal breaker on enthusiast grade lights. I much prefer to keep an eye on voltage, capacity, and IR by using a dedicated analysing charger such as the Vapcell S4 Plus.
For consumer orientated flashlights, I would mark down a product in a review if it lacked USB charging as the average person buying one is unlikely to be knowledgeable Li-ion batteries.

I would call myself an enthusiast, but, I mean, even my slim phone has USB-C charging. It’s an EDC/ Ease of use thing. if I know i just can plug it in to the charger, hassle free in the afternoon, that would mean the world. Apparently not for all so it seems.

Forsythe P. Jones
Offline
Last seen: 1 year 3 months ago
Joined: 08/15/2021 - 00:40
Posts: 413
Location: California

Interesting review. I hadn’t heard of light painting before, at least in connection with fancy flashlights. Of course if you don’t like the strobe pulse length in party mode, you can always reprogram it using the reflash adapter. That might be worth mentioning in the review, in case readers might want to reprogram the light themselves. If you’re not up for messing with the software, there are probably people here who can do it for you, as it should be a pretty simple change. You’d then have to download a new hex file and load it into the light, of course.

stephenk
stephenk's picture
Offline
Last seen: 21 hours 16 min ago
Joined: 01/30/2016 - 05:09
Posts: 2409
Location: Australia

Forsythe P. Jones wrote:
Interesting review. I hadn’t heard of light painting before, at least in connection with fancy flashlights. Of course if you don’t like the strobe pulse length in party mode, you can always reprogram it using the reflash adapter. That might be worth mentioning in the review, in case readers might want to reprogram the light themselves. If you’re not up for messing with the software, there are probably people here who can do it for you, as it should be a pretty simple change. You’d then have to download a new hex file and load it into the light, of course.

Realistically, >99% of the light painters reading the review will not be re-programming it, especially when there are other options on the market with a 5ms on-time strobe with less of an impact on brightness. So it’s really a case of reviewing what is available out of the box.
Forsythe P. Jones
Offline
Last seen: 1 year 3 months ago
Joined: 08/15/2021 - 00:40
Posts: 413
Location: California

If you think 5ms strobe pulse is a good addition to the light in general, it’s reasonable to suggest it to Hank and/or ToyKeeper. If you want it for just your light, it looks like you can just change PARTY_STROBE_ONTIME to 5 (milliseconds) in the appropriate header file for your light model, rebuild Anduril, and reflash. I can make you a new hex file if you want, though you’ll have to reflash the light yourself. Reflashing requires buying the reflash gadget from Hank ($14.50 USD, don’t know about AU), unless you know someone who already has one. I expect there are users in AU who have them.

ToyKeeper
ToyKeeper's picture
Offline
Last seen: 6 days 20 hours ago
Joined: 01/12/2013 - 14:40
Posts: 10896
Location: (469219) 2016 HO3 // I get way more privmsgs than I can respond to, so please ask in a public thread if possible, for a faster answer.

Great review! You always make such pretty pictures…

I’m not sure if it’s of any interest, but most lights should be shipping with Anduril 2 now, which has a bunch of improvements. In particular, it helps address the issues with being too complex for many users, and makes it harder to get the wrong mode by accident. There aren’t many changes which are relevant to light painting though… just a couple little things:

  • Momentary mode is available directly from strobes and regular ramp modes, without having to turn the light off.
  • Strobe pulses are more consistent in duration/brightness, since it resets the waveform phase before each pulse.

It still doesn’t have a runtime option to use stepped ramping for strobe speed though, or the ability to adjust duty cycle or brightness for party and tactical strobes.

One minor correction… The KR1 doesn’t typically use PWM. The driver is a constant-current linear model, so output should be pretty steady with very little ripple and no actual pulses. It’s possible that some models use a DD FET for the highest modes too, but I’m not sure if Hank ships any that way or if they’re all purely linear. In either case though, it shouldn’t have any visible pulses, just a bit of fast ripple between ~1900 and ~2300 lm.

I’d definitely recommend getting the flashing kit along with the light, since updates are still happening somewhat often, and it allows for deeper customization. Like, as FPJ pointed out, the party strobe duty cycle can be configured by changing a single value.

For fairy dust effects, does it work to put some DC-Fix on the lens? It should make aiming easier, but I’m not sure if it impedes the starburst flare.

stephenk
stephenk's picture
Offline
Last seen: 21 hours 16 min ago
Joined: 01/30/2016 - 05:09
Posts: 2409
Location: Australia

ToyKeeper wrote:
Great review! You always make such pretty pictures…

I’m not sure if it’s of any interest, but most lights should be shipping with Anduril 2 now, which has a bunch of improvements. In particular, it helps address the issues with being too complex for many users, and makes it harder to get the wrong mode by accident. There aren’t many changes which are relevant to light painting though… just a couple little things:

  • Momentary mode is available directly from strobes and regular ramp modes, without having to turn the light off.
  • Strobe pulses are more consistent in duration/brightness, since it resets the waveform phase before each pulse.

It still doesn’t have a runtime option to use stepped ramping for strobe speed though, or the ability to adjust duty cycle or brightness for party and tactical strobes.

One minor correction… The KR1 doesn’t typically use PWM. The driver is a constant-current linear model, so output should be pretty steady with very little ripple and no actual pulses. It’s possible that some models use a DD FET for the highest modes too, but I’m not sure if Hank ships any that way or if they’re all purely linear. In either case though, it shouldn’t have any visible pulses, just a bit of fast ripple between ~1900 and ~2300 lm.

I’d definitely recommend getting the flashing kit along with the light, since updates are still happening somewhat often, and it allows for deeper customization. Like, as FPJ pointed out, the party strobe duty cycle can be configured by changing a single value.

For fairy dust effects, does it work to put some DC-Fix on the lens? It should make aiming easier, but I’m not sure if it impedes the starburst flare.


Thanks for the feedback, and your ongoing hard work on Anduril.
I was expecting this KR1 to ship with Anduril 2 (which I’ve reviewed on the Emisar DT8), but sadly it came with Anduril 1.
I’ve changed the PWM bit in the review.
Personally I think the party strobe pulse is too short – the 5ms pulse on the LightPainter torch is more useable for light painting as it has less of a brightness impact, though 4ms should be sufficient.
The starburst effect comes from the LED, so diffusing the beam creates a not so good starburst. A small shallow reflector (or even mule), with small LED would probably be optimal – single CSLNM1 mule anyone?
I’ll note that I write my reviews more towards the consumer orientated light painting/night photographer market – I think barely any non-enthusiast readers of my reviewers would be prepared to flash firmware, half of em can’t even work out how to access strobe mode in Anduril!
Forsythe P. Jones
Offline
Last seen: 1 year 3 months ago
Joined: 08/15/2021 - 00:40
Posts: 413
Location: California

Stephenk, do you think a lot of light painters care about this? Maybe we could give Hank a special software build customized for light painters (5ms strobe pulse etc.) and people who wanted that software could just order the light with it installed. It would still be the same light, so the software could always be changed afterwards using the flash gizmo, by those inclined to do that sort of thing.

stephenk
stephenk's picture
Offline
Last seen: 21 hours 16 min ago
Joined: 01/30/2016 - 05:09
Posts: 2409
Location: Australia
Forsythe P. Jones wrote:
Stephenk, do you think a lot of light painters care about this? Maybe we could give Hank a special software build customized for light painters (5ms strobe pulse etc.) and people who wanted that software could just order the light with it installed. It would still be the same light, so the software could always be changed afterwards using the flash gizmo, by those inclined to do that sort of thing.

Good idea, but I don’t think there would be enough orders to make it worthwhile. Now if the special build could run the strobe at the last ramped/stepped brightness setting, then it could rival what is currently the best flashlight for light painters (Light Painting Paradise LightPainter, which is a modded SP31 V2.0 built in small production runs), though as I’m an ambassador for that company it’s not worth me creating a rival product Wink There is one person in the light painting scene with a massive online following who could develop something like this and sell a lot, but I don’t think he understands anduril enough.

Forsythe P. Jones
Offline
Last seen: 1 year 3 months ago
Joined: 08/15/2021 - 00:40
Posts: 413
Location: California

Quote:
if the special build could run the strobe at the last ramped/stepped brightness setting
This sounds doable, though I’ll look at the code to make sure. There are already a lot of different strobe modes (party, tactical, lightning storm, candle, bike flasher, maybe more) so adding another (light painter) doesn’t sound excessive, especially since it’s just a slight variation on party strobe.
thefreeman
thefreeman's picture
Online
Last seen: 6 min 6 sec ago
Joined: 01/06/2020 - 09:56
Posts: 1816
Location: France
stephenk wrote:
Unfortunately the “motion freezing” party strobe is not very bright, being 3 photographic stops dimmer.
ToyKeeper wrote:
One minor correction… The KR1 doesn’t typically use PWM. The driver is a constant-current linear model, so output should be pretty steady with very little ripple and no actual pulses. It’s possible that some models use a DD FET for the highest modes too, but I’m not sure if Hank ships any that way or if they’re all purely linear.

The XP-L HI KR1 that I bought only uses the constant current (CC) channel, I’m guessing that if the SST-40 uses the 7.5A configuration that is also the case.

The CC channel has a rise time that looks like this :

As you can see it takes 7.5ms to reach 90% of its set output.
I think the party strobe is slowed down to min 2ms pulse (?), so it reaches only 45% of the set output (in theory), does that corresponds to 3 photographic stops vs 100% ?

The driver could be modified to have have a faster rise time by decreasing the capacitor value of the PWM low pass filter, this increases ripple so to compensate use fast PWM instead of phase correct PWM, this doubles the PWM frequency, so we can halve the rise time without increasing the ripple. We can halve again the C value ( 1/4 ) to again halve the rise time :

Doubling the ripple (here at 10% output, ripple % close to max, 100% output = no ripple, 0.1% output = max ripple %) but IMO still largely acceptable, it could even be halved again ( 1/8 ) to get an even faster rise time and still have an OK ripple.

Not saying you should modify your light, but this is something that Hank could maybe offer, it’s one component change and one code change.

(Edit : with dynamic PWM the frequency is higher now right ? so by default the capacitor value could be reduced anyway)

ToyKeeper
ToyKeeper's picture
Offline
Last seen: 6 days 20 hours ago
Joined: 01/12/2013 - 14:40
Posts: 10896
Location: (469219) 2016 HO3 // I get way more privmsgs than I can respond to, so please ask in a public thread if possible, for a faster answer.

thefreeman wrote:
… one component change and one code change.

with dynamic PWM the frequency is higher now right ?

Or… if the KR1 driver actually has a DD FET (I’m not sure if it does), the light could just use that for party strobe. It’d have a dramatically faster rise and fall time, so it could make a shorter, brighter pulse. However, this would only be safe on some of the emitter types. It might damage a W1 or 219B, and would almost certainly kill an E21A. However, it’d almost certainly be fine for XP-L and SST-40 and SST-20.

stephenk could find out by flashing the KR4 linear+FET firmware and checking if strobes still work. It should either have a snappier party strobe, or none at all, depending on whether the FET is physically there.

As for your question… With dynamic PWM, the frequency is modulated and it goes both faster and slower. Instead of always running at 4 kHz, it goes anywhere from 60 Hz to 16 kHz. It’s slower on low modes and faster on high modes.

At some point, I might try to implement delta-sigma modulation instead of pulse frequency modulation, so it could keep faster pulses even on low modes… but that’s a project for later. It wouldn’t directly help with rise/fall speeds, but it could potentially make a weaker lowpass filter feasible.

ToyKeeper
ToyKeeper's picture
Offline
Last seen: 6 days 20 hours ago
Joined: 01/12/2013 - 14:40
Posts: 10896
Location: (469219) 2016 HO3 // I get way more privmsgs than I can respond to, so please ask in a public thread if possible, for a faster answer.
stephenk wrote:
if the special build could run the strobe at the last ramped/stepped brightness setting, then it could rival what is currently the best flashlight for light painters …

I’ve been wondering how the interface should work for more detailed strobe controls. There are three main parameters…

  • Pulse frequency
  • Pulse length
  • Pulse intensity

It currently sets the intensity to full power, with an adjustable frequency and two different lengths to choose from. Button mappings are 1H to increase frequency or 2H to decrease frequency.

Intensity could be copied from the main ramp’s memorized level, but then it’d be locked in while actually in strobe mode. It seems like it’d be nicer to be able to adjust the brightness during use instead.

Would also be nice to adjust the length during use, which isn’t currently supported at all.

With all of those though, it’d need to use like… 1H for frequency, 2H for brightness, and 3H for length? 1H+2H for freq, 3H for brightness, 4H for length? Other? Not sure what would work best.

Regardless, none of it would be adjustable from within momentary mode, because it already reserves all button presses for on/off.

Assuming all the UI details got worked out and it was implemented, there’s still one more question. How many strobe modes should it actually have, in total?

  • Party strobe: pulse as short as possible to stop motion
  • Tactical strobe: intended to disorient people
  • Light painting strobe: fully adjustable for visual effects

Would the light painting mode replace both of the others, just one, or would it be an additional mode? Maybe it’d replace both, but have two sets of config values so it can basically store two adjustable presets?

I don’t know the answers. Mostly would like to hear what people think.

If the pulse length becomes adjustable, there’s one more complication: it’ll become important to implement thermal regulation in strobe modes. That’s not easy, but if I’m going to raise the maximum average power level, it kinda needs to make sure it doesn’t start fires.

thefreeman
thefreeman's picture
Online
Last seen: 6 min 6 sec ago
Joined: 01/06/2020 - 09:56
Posts: 1816
Location: France

ToyKeeper wrote:

Or… if the KR1 driver actually has a DD FET (I’m not sure if it does), the light could just use that for party strobe. It’d have a dramatically faster rise and fall time, so it could make a shorter, brighter pulse. However, this would only be safe on some of the emitter types. It might damage a W1 or 219B, and would almost certainly kill an E21A. However, it’d almost certainly be fine for XP-L and SST-40 and SST-20.

As for your question… With dynamic PWM, the frequency is modulated and it goes both faster and slower. Instead of always running at 4 kHz, it goes anywhere from 60 Hz to 16 kHz. It’s slower on low modes and faster on high modes.

At some point, I might try to implement delta-sigma modulation instead of pulse frequency modulation, so it could keep faster pulses even on low modes… but that’s a project for later. It wouldn’t directly help with rise/fall speeds, but it could potentially make a weaker lowpass filter feasible.

Yep that’s simpler.

Thanks for the precision about the frequency.

stephenk
stephenk's picture
Offline
Last seen: 21 hours 16 min ago
Joined: 01/30/2016 - 05:09
Posts: 2409
Location: Australia
ToyKeeper wrote:
stephenk wrote:
if the special build could run the strobe at the last ramped/stepped brightness setting, then it could rival what is currently the best flashlight for light painters …

I’ve been wondering how the interface should work for more detailed strobe controls. There are three main parameters…

  • Pulse frequency
  • Pulse length
  • Pulse intensity

It currently sets the intensity to full power, with an adjustable frequency and two different lengths to choose from. Button mappings are 1H to increase frequency or 2H to decrease frequency.

Intensity could be copied from the main ramp’s memorized level, but then it’d be locked in while actually in strobe mode. It seems like it’d be nicer to be able to adjust the brightness during use instead.

Would also be nice to adjust the length during use, which isn’t currently supported at all.

With all of those though, it’d need to use like… 1H for frequency, 2H for brightness, and 3H for length? 1H+2H for freq, 3H for brightness, 4H for length? Other? Not sure what would work best.

Regardless, none of it would be adjustable from within momentary mode, because it already reserves all button presses for on/off.

Assuming all the UI details got worked out and it was implemented, there’s still one more question. How many strobe modes should it actually have, in total?

  • Party strobe: pulse as short as possible to stop motion
  • Tactical strobe: intended to disorient people
  • Light painting strobe: fully adjustable for visual effects

Would the light painting mode replace both of the others, just one, or would it be an additional mode? Maybe it’d replace both, but have two sets of config values so it can basically store two adjustable presets?

I don’t know the answers. Mostly would like to hear what people think.

If the pulse length becomes adjustable, there’s one more complication: it’ll become important to implement thermal regulation in strobe modes. That’s not easy, but if I’m going to raise the maximum average power level, it kinda needs to make sure it doesn’t start fires.

I think setting brightness > strobe frequency > saving settings would work, that’s how the LightPainter works. I don’t think there is any need for a 3rd strobe mode, it just needs to be able to adjust brightness of the two existing strobes, maybe by using last ramped/stepped brightness. The Tactical Strobe would maybe be better with 50/50 on/off time instead of 33/67 on/off time, though it’s passable . The Party Strobe needs to be either slightly longer or have a faster rise and fall in the pulse as discussed in this thread. Another improvement would be the ability to exit momentary without having to unscrew the tail cap.