Emisar D4 (Nichia 219c) Flashlight Review


I tend to get suckered in to the newest things….  And when those newest things involve Nichia, I end up with new lights.  This is one of those new things, the Emisar D4.

Official Specs and Features

• CNC machined from aircraft-grade aluminium
• Efficient UK made Carclo Quad LED optics
• Anti-reflective coated glass lens
• Unihead construction
• High lumen output and low moon output
• Ramping interface
• Electronic soft touch switch (ALPS)
• Beryllium-Copper springs with 45% IACS superior to stainless steel alloys used for springs
with only 2% IACS.
• Temperature step-down
• Waterproof and dustproof to IP67 standard (up to 1 meter)
• Default 18650 body with optional 18500 or 18350 battery tube
• Dimensions: 94mm(length) * 28mm(head) * 24mm(body), 80mm(lenght 18500), 63.5mm(lenght 1835)

OTF lumen output at start-up
XP-G2 S4 : 3300lm
Nichia 219C : 3800lm
XP-L HI : 4300lm


There are quite a few options on this light.  First of all there are three body colors: Black, Gray (seen here), and Green.  Then there’s the ‘shorty tube’ which allows the use of a single 18350.  These shorty tubes are available separately, in the same colors as the bodies.  And there’s even an 18500 tube option too, also available in all 3 colors.  There are also a bunch of emitter options!

Cool White – XP-G2 S4 2B, 5700K
Neutral White – XP-G2 S4 3D, 4885K
Neutral White – XP-G2 S4 5D, 4000K
Neutral White – Nichia 219CT 83CRI, 5000K (seen here)
Cool White – XP-L HI V3 1A, 6500K ( +$18.00 )
Neutral White – XP-L HI V2 3A, 5000K ( +$18.00 )


Around $40, and another $5 for the shorty tube.  There really aren’t any discounts on these yet, and only two places to get them.

Short Review

This is a great light.  Even better with the new UI and probably better still with the UI that u/ToyKeeper has been playing around with.  The output of this light is truly astounding, but boy does it get hot.  (Like, hot hot. You’ve been warned.)

Long Review

What’s Included

  • Emisar D4
  • Spare o-rings (3)


Note: The shorty body is a separate purchase.
Note: That pocket clip is one I had from another light, and is not included with (or really intended for) the D4.

Package and Manual

The Emisar D4 package is a simple corrugated box, with the model specifics hand written.  Even the model is not printed, because there’s another Emisar model now!! (The D1, which is a thrower version of this light, sort of).  The handwriting shows the emitter option, too.


There is no manual.  All of that info can be found on the website.   UI is included there too.

Build Quality and Disassembly

This is an inexpensive light, but it’s not really cheap.  It’s similar to Convoy brand, but probably a step up in quality.  I have found the anodizing to be a bit thin, and using a friction clip from the Convoy lights has scratched the anodizing a fair amount.  However this is true of other, more expensive lights, too.

Parts-wise, the D4 is an excellent buy.  Even just for the 4 emitters, this is a great buy.

Here you can see the 18650 configuration.  It’s really a small light – maybe thick for what it is, but that’s a good thing for how much heat the light has to deal with.

And this is the 18350 configuration.  This little hotrod won’t shine for long on high with an 18350, but it’ll be small the whole time it’s doing it.

Here are the parts disassembled.  I didn’t take the head apart (side switch heads like this intimidate me in that way).  But be aware that removing the driver isn’t all that easy, as it’s held in place by thermal epoxy (or maybe just potted, I’m not sure.)  Notice that the threads are quite beefy, and also square cut (my favorite).  They’re also anodized, which I also prefer.  The cell tube is thick and not tapered.  Also note that the cell tubes are directional – the thread area is twice as long on one end as the other.

The bezel unscrews from the head easily, and the optic can be removed too.  The feet of the optic rest in holes on the mcpcb, as seen in the last photo of this group.


The shorty is short indeed.  The longer of the two is still quite small for what it is!

The 18650 variant is actually smaller than the Zebralight SC600.  Not that these two are comparable lights (the SC600 I have is more of a pocket thrower).  But still it’s a good size reference.


As provided, this is a pocket light.  There’s no pouch, magnet, or clip.  The body is ready for a clip – the 18650 has a slot on the head and tail both for a friction clip.  But one isn’t provided, linked, or mentioned.  I found that a clip I have for the Convoy S2+ works respectably well, and that’s what I’ve been using.  The light has come off that clip a couple of times, though.

Otherwise, the light just has to be thrown in a bag or pocket or something.  I’m ok with this.  It’s nearly small enough.


Power is provided from a single 18650 (or a single 18350, or a single 18500) cell.  It’s not recommended to run the light with 18350×2 in the 18650 tube (if they’ll even fit), as I’m pretty sure you’d break something.  I’m just not sure what you’d break first.  There’s no voltage rating on the driver, either, so 2-up cells would likely be over voltage.  (Prepublication edit:  I can’t find this anywhere official except ToyKeeper’s review, but I consider her official: Operating voltage: 2.8V to 4.35V.)

The D4 is fairly cell indifferent, but it does not like long protected cells.  And really it’s the length that’s the problem, not the protection.  That said, it doesn’t love protection either, because most protected cells will trip protection on the extremely high drain requirements of turbo with this light.

Even just using one high drain cell (and boy does this light like high drain cells), you can still break things.  Below is the only runtime test I did with this light, in part because the D4 killed the cell I was using, and Efest Purple 3500mAh “10A continuous/20A pulse” button top cell.  This was the highest drain cell I could find in my house.

As you can see in the runtime, around 3.5minutes in, the light just dies.  Turns out it’s the cell dying (and it is dead, for certain.  Not “I don’t want to go on the cart” dead.)  I’m not exactly sure what killed it.  The light was certainly hot (at about 70°C on the very exterior of the body).  And it was certainly pulling some current.  It was an unprotected cell, so the protection didn’t trip.  Turns out “almost all” cells have a certain level of protection built in.  You can read more here if you’re so inclined.  I suspect what happened is that the temperature caused the cell to expand, and the pressure caused the CID to trip.  But that’s just best guess.  The cell didn’t have a black box.

All of that said, this cell was likely not the best choice for this light.  Efest cells don’t have a reputation for honest labels.  While they may operate fine, the specs are probably specious.  Something like a Sony VTC6 would be better (15A continuous).


I’m not going to do another runtime on the light, because I don’t really relish killing cells.  I’ll add that you should note how absurdly fast the temperature skyrockets.  Less than 3 minutes to hit over 70°C on the exterior of the light.  It’s too hot to hold WELL before that point.  Also in my opinion, the light doesn’t deal with heat all that well – even after I turn the fan on the temperature doesn’t drop, it just levels out.

It’s very much worth noting that this is VERSION ONE of the firmware.  What ships now is version 2 (at the very least) and has some fixes that include fixing the thermal stepdown (per ToyKeeper).

User Interface and Operation

There’s a single side clicky e-switch on the D4.  It’s nicely clicky, and big enough to be found easily, and it has a texture that helps with grip.  Since all versions shipping now are the new UI, there’s no point in me putting out the info about this version (since I have v1 UI).  I’ll summarize by saying that this is a ridiculously versatile UI, with ramping and battery check, among other things.  At the price of this light, it’s worthwhile just to buy for the Nichia 219c’s, and the awesome UI.


LED and Beam

My version of the D4 has four Nichia 219CT 83CRI in 5000K.  The beam is fairly rounded, but if you rotate the light you can probably pick up a square-ish profile due to the quad putting the emitters in a square.  The beam is fairly concentrated.  Not throwy, but also not quite all flood as one might expect with this quad.

The tint is really a very clean white.  The 219c does not have the famous rosy aspect of the 219b, but the tint is really just pure white.  If I’d never had a 219b, then I’d say 219c is an apex of emitter tint.


Tint vs BLF-348

It’s deceiving….  The left is the D4, and it’s not really green at all.  My BLF-348s are just really rosy.


Beamshots, Runtime, and Lux Measurements

Emisar D4
Emitter Nichia 219c
Emitter Notes 5000K 80+ CRI – Neutral White
Cell 18650
Glamour Shots Beamshots [0.3″, f/8, ISO 100, 5000k]
Runtime 18650
LVP? Yes
Claimed Lumens (lm) 3800
Lux (Measured) 444
At (m) 5.759
Candela (Calculated) in cd 14725.7
Throw (Calculated) (m) 242.7
Throw (Claimed) (m)

Random Comparisons and Competitive Options….

I won’t play like there’s anything non-custom that compares, based on output alone. If you’re looking for other quads, however, look at the Astrolux S41.  If the UI ever gets updated on the S42, consider it too.  The S41 has Nichia as well, is a bit of a hot rod, and seems less likely to kill your cells.


What I like

  • Inexpensive way to get a true hotrod
  • Inexpensive way to get 4x Nichia 219c
  • Great beam profile and tint
  • Output is O_O
  • Various cell tube sizes add versatility

What I don’t like

  • Thermal management needs work (and got it with V2).
  • Anodizing is very thin
  • Lack of proper pocket clip (skip the friction clip and add a collar clip? that’d be fun.)
  • Low isn’t low enough (fixed in V2!)

Up Next

Some knives, and the Armytek Elf C2.  I also have 4 lights by Favour that should be up soon.


  • This light was provided by me for use. I did not pay myself to write this review.  Though in the future that’s something I’m going to look into.
  • This content originally appeared at zeroair.wordpress.com.  Please visit there for the best experience!
  • Whether or not I have a coupon for this light, I do have a bunch of coupons!!  Have a look at my spreadsheet for those coupons.
  • Provided to you for your enjoyment, with no proofing whatsoever.

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