Emisar D4S review

I think my Samsungs are U6 binning, lot of room on top but they’re considerably brighter than the current 90CRI offering which is why I went with the 80’s… splitting differences as it were.


Love the idea of making the AUX LED’s breathe!

In terms of max lumens on XP-sized emitters, the scale is generally (from most to least):

  • XP-L2 HD
  • LH351D
  • XP-L HD
  • XP-L HI
  • XP-G3
  • 219c
  • XP-G2
  • 219b
  • XP-E2

If I recall correctly, at least. Assuming other things are equal, like color temperature and CRI. Warmer tints and lower CRI generally produce fewer lumens per watt.

So it’s not at all surprising that a LH351D would beat XP-G2 on lumens. It’s enough steps above that it can still put out more light even with somewhat higher CRI.

The Meteor isn’t a very good way to gauge emitter capabilities. It doesn’t run the emitters as hard as they can go, and it is limited by Amps instead of Watts so it will generally deliver more power to older higher-voltage emitters, like the XP-G2.

Not really. The breathing effect costs a lot of power. Instead of just powering the LEDs (0.03 to 0.90 mA), it requires keeping the MCU awake to pulse the emitters on and off fast enough that it looks like it’s dimming. The MCU by itself requires several times as much power as the LEDs (2 to 6 mA). So “breathing” mode would be less bright and have only a fraction as much runtime.

You could make it “breathe” by changing the firmware, but I don’t think it would be worthwhile.

A point to ponder…

The availability of the Samsungs to date shows us only about mid range output levels. The binning goes up to “W” and then in increments of 1 all the way to 9… I used U6 bin so as you can see, there is a lot more to be discovered from Samsung while Cree is being left behind. The XP-L2’s are not very pretty for flashlights.

Given a disregard for CRI clarity, there are some significantly more powerful Samsung’s available that easily match the Cree XP-L2 in output, showing over 2000 lumens per emitter. I opted for the 80 CRI in 5000K tint to achieve some of the best of both worlds, but am seriously considering going for some of their top bins available just to see what gives. :wink: I mean, sure, 5920 lumens sounds really nice and all, but it’s only a measly 1480 lumens per emitter, now on the other hand if I’d left smaller wires in place and purposely limited high current draw then it would be easier on the light, give a more efficient output and in a very pleasing tint with high color rendering. So perhaps it’s time we look at quality a lot harder than quantity.

I know, right? :wink:

The tail magnet is so powerful in mine I was walking around with a c-cell battery attached to the outside of my cargo pocket, until my son asked me what kind of voodoo I was performing. I also wondered how long I had my fly open

I want to say thank you for putting this all together…. Along with Toymaker providing updated configs, it really helps people like me getting into the hobby of flashing flashlights.

Ah, but is this one a good candidate to flash? Will Anduril run the auxillary lights?

Yes, currently it’s the best one since you can flash it without a full disassembly.

And yes, aux LEDs work but they have different shortcuts to change the modes

TK must’ve upgraded Anduril since my last download.

I had the D4S fully disassembled in short order, flashing the MCU wouldn’t be a problem and I’ve thought about upgrading the FET as well but haven’t yet. I’m already set up to flash MMU boards so plugging in to the D4S driver shouldn’t be difficult either, just want to find out if the auxillary led’s are fully supported before I change anything. I keep messing up and going into Tactical momentary lockout as I’m used to 4 clicks doing lockout on Anduril . Ugh.

Edit: Now running Anduril-D4S. Wondering where to find a diagram on how to tune the auxillary LED’s, can’t seem to locate that… Thank you once again TK, awesome work and very much appreciated!

When I flashed Anduril it seemed simplest to remove the driver to do so. In the process I went ahead and tried to tone it down a bit and swapped the 18ga leads put in yesterday for smaller 20ga Teflon coated leads. This ended up with a whole 276 lumen drop, so not enough to even notice. Oh well. An attempt was made… lol

Yes, I got Anduril working first, then created RampingIOS V3 by removing and rearranging things until it matched Hank’s spec.

Same as the Q8: (Q8 and GT builds of Anduril, or anything with a lighted button)

  1. Go to lockout mode.
  2. To change aux LED behavior…
    • Click 3 times to change lockout mode aux LED settings.
    • Click 3 times and hold the last press to change “off” mode aux LED settings. Release when it gets to the setting you want.

The modes are: off, low, high, or blinking.

Compared to a Q8, the main firmware difference is that the aux LEDs won’t turn on unless the main LEDs are off.

Is it a MMU-style chip now? I haven’t taken the driver out of mine yet to look…

This isn’t as good as Lexel’s flashing adapter, but I found the D4S was pretty easy to reflash with a usbasp, a ribbon cable, and some solid-core wire:

what gauge wire are you putting in the flash holes?


I merely meant that I have wires set up for the board that flashes the MMU for a 10mm driver. So I have tinned wires set up on the USB ASP. They’re set up in a 4x2 arrangement though, not the 3x3 of the Emisar D4S, so it would still require some finagling for me to be able to flash it in the light, hence why I pulled the driver to flash it. Meant to also change the FET but did not, having some issues today not flashlight related…

Thank you for pointing me at that UI. I had already figured out the triple clicks to change levels in lockout but forgot about the “hold” for on-time use. prc8 it.

With Anduril. NarsilM doesn’t have those settings.

I’m not sure what gauge the wires are. I found it in a drawer long ago, and there is no label anywhere. I’m guessing 26 gauge. Maybe 24.

I should probably add it to the diagram somewhere, but there isn’t a good place to put it… and it’s only relevant to some of the supported hosts. So it remains sort of hidden.

Those guesses are good enough to keep my scavenging to a minimum…

assuming bare male jumper pins are too big?


Have you verified that these DuPont pins will fit in the programming holes of the D4S? Because all of my DuPont connector pins are too fat for the holes drilled in the D4S board, and I had to build a programming harness with some solderless bread board jumpers that did fit.

I was originally going to use some jumper pins, but I couldn’t find any in my parts bins. So I used some random wire I found instead.

Hopefully Lexel’s flashing connector will become pretty standard soon, but for now things are a bit more ad-hoc. I refer to the pinouts in flashlightwiki whenever I flash the D4S. This is fine for one-time or occasional flashing, but inconvenient during development. So I still do most of my development on a decapitated Emisar D4 with its brains hanging out. It works fine as long as I don’t need to do thermal testing or hardware-specific stuff.