Emisar D4s Flashlight Review

The Emisar D4s is a flashlight featuring the Andúril user interface, an e-switch, and running on a single 26650 cell. And it’s a nice green!

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Official Specs and Features

Here’s a link to the Emisar D4s Flashlight product page.

Versions

There are a bunch of options on this light.  First, the emitters:

Neutral White – Nichia 219CT 90CRI, 5000K
Cool White – SST20 6500K
Neutral White – SST20 5000K
Neutral White – SST20 4000K 95CRI
Warm White – SST20 3000K 95CRI
Cool White – XP-L HI V3 1A, 6500K ( +$15.00 )
Neutral White – XP-L HI V2 3A, 5000K ( +$15.00 )
Neutral White – XP-L HI V2 5D, 4000K ( +$15.00 )
Cool White – XP-L HD V6 1A, 6500K ( +$15.00 )
Neutral White – XP-L HD V6 3D, 5000K ( +$15.00 )

Then there are secondary emitters, and there are some options there too!  Cyan (default), Amber, Red, and Green are all choices.

There are body color options, as well!  Black, Grey, and Green are the choices.

I have a green body, Nichia 219c emitter light, with Amber secondaries.

Price

The D4S starts at $48 and goes up from there based on the options you pick.

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Short Review

This is a very fun light and in my opinion probably a little better quality than most of the other Emisar lights I’ve had. The secondary emitters are great and the build quality is fine. And the UI is fantastic, too!

Long Review

The Big Table

Emisar D4s
Emitter:	Nichia 219CT (90CRI, 5000K)
Price in USD at publication time:	$48.00
Cell:	26650
Turbo Runtime	High Runtime
LVP?	No
Switch Type:	E-Switch
Quiescent Current (A):	?
On-Board Charging?	No
Claimed Lumens (lm)	3000
Measured Lumens (at 30s)	1956 (65.2% of claim)^
Claimed Throw (m)	283
Candela (Calculated) in cd (at 30s)	727lux @ 5.143m = 19229cd
Throw (Calculated) (m)	277.3 (98% of claim)^
All my Emisar reviews!

^ Measurement disclaimer:  Testing flashlights is my hobby. I use hobbyist-level equipment for testing, including some I made myself. Try not to get buried in the details of manufacturer specifications versus measurements recorded here; A certain amount of difference (say, 10 or 15%) is perfectly reasonable.

What’s Included

• Emisar D4S flashlight
• Spare o-rings (2)
• Lanyard

Package and Manual

This light ships in a cardboard box with a generic sticker. The light specifics are then handwritten on the sticker. It’s a good solution.

My light did not come with a manual. For the most part, information for using the light will come from the product page itself.  (Here is that page.)

Build Quality and Disassembly

As I said above, this light is at least as well built as the other Emisar lights I’ve had.  In particular the anodizing has improved, though “improved” might be a personal preference.  I was not (and am not) a fan of the chalkboard finish on many Emisars (and Armytek, for that matter).  But this green anodized D4S is a nice glossy finish and feels like a nice quality finish.

In this tailcap is one of the strongest magnets I can remember on a light.  Every time I take the cap off, it pulls the cell out of the tube!

I really didn’t disassemble further than this.  The D4S is one of the few lights with programming pins accessible without even removing the driver (!!!).  That’s a huge thing!!  Both the driver and tailcap bits look to be press-fit, but I’m honestly not sure about that.

The threads on the head and tail both are anodized, square-cut, and properly lubed.  It’s possible (and recommended) to manually lock the light out by unscrewing either the head or tail a bit.  Though a pocket clip is not included, there’s a spot fit for one, but only on one end of the cell tube.  But since the cell tube is reversible, the clip can go in either orientation.

Size and Comps

Officially the light is

• Dimensions: 105mm (length) * 39mm (head) * 32mm (body)

It’s not a thin light, but then it is a 26650 light.  So it’s not really thicker than you’d expect.  It is short overall I’d say, coming in quite a bit shorter than the S2+.  Here’s the test light with the venerable Convoy S2+.  Mine’s a custom “baked” edition Nichia 219b triple.  A very nice 18650 light.

And in hand, it’s a very nice using-size.

Retention and Carry

Really the only proper means to carry the light is the lanyard.  There’s a lanyard included, and the only place to connect it is in the tailcap.

There’s also a magnet in the tailcap, which is very strong.  There’s no problem sticking it horizontally; the light stays stuck just fine.  It’s so strong that if you take the head off the light, the cell is very reluctant to drop out.  In fact, you’ll have to shake it out with some force!

Power and Runtime

The D4S is powered by a 26650 Li-ion cell.  I opted to purchase the one from the Emisar store.  It’s a Liitokala 5000mAh cell.  Flat top, and unprotected.  There’s no current claim on the cell.  (I do have other 26650 cells like the one I reviewed yesterday, which do have current claims.  I tested the light only with the cell available from Emisar, so you will have a better idea of what you’re getting if you buy that cell.)

There are no adapters included, but there’s no reason the light won’t work with 18650 cells, too.

Here are a couple of runtimes.  The thermal regulation seems to make the output jump around quite a bit.  I didn’t notice this during the test, but I can’t say if you’ll notice it during use.  The jumps aren’t insignificant, but they’re over a time frame where they might be quite subtle.

Also noteworthy is that the light tests quite a bit under the claimed output.  That’s entirely cell-dependent, and I suppose this Liitokala cell doesn’t provide the current needed for long enough to maintain the initial output (of 2500 lumens), or hit the max claimed output of 3000 lumens.  If I was you, I’d probably snag a different 26650 for this light, if your goal is max lumens for longest time.

The output on high (where “high” is the top of the regulated ramp) is much more stable.

I tested the light on bench power and did not see any evidence of LVP.  The light does step down dramatically, so when you’re seeing very low output, charge your cell.

Pulse Width Modulation

A new section!  I am new to measuring PWM, and my setup is very rudimentary (which can be said about almost all of my setups?  eek).  But this is something I’ve wanted to add for ages – I’m very PWM sensitive, and knowing whether a light has visible PWM is very useful to me.  While there does appear to be some PWM on the lower modes (of the stepped setup), I don’t find this to be visible.  And if I don’t, I expect you will not either.  By the fourth step (below), the light does not display any PWM at all.

This is the lowest mode with the ramping setup.  Again, trust me the PWM isn’t visible in normal use.  I am not yet able to calculate the Snob Index, but maybe one day I’ll get that capability too.

User Interface and Operation

There’s only one switch on the D4s.  It’s a side e-switch.  It’s very clicky but still fairly quiet.

While this UI looks almost exactly like Andúril by ToyKeeper, it’s only just that: almost exactly like Andúril.  It’s close enough that you’ll be familiar with this UI very easily if you have any Andúril lights.

Here’s a UI table!

State	Action	Result
Off	Hold	On (Low)
Off	Click	On (Mode Memory)
Off	Click 2x	Highest Hybrid Mode
Off	Click 3x	Battery Check
Off	Click 4x	Tactical Momentary (turn this off by breaking the cell contact)
Off	Click 5x	No action
Off	Click 6x	Lockout
Off	Click 7x	Next Aux mode (Off, Low, High)
Off	Click 8x	Beacon
Off	Click 10x	Thermal Configuration
Batt check	Click 2x	Temp Check
Lockout	Click 3x	Next Lockout Mode (This one is a bit unclear!)
Beacon	Click 4x	Beacon Config
On	Click 3x	Switch between Stepped and Smooth Ramp
On	Click 4x	Ramp Configuration
Lockout	Click 4x	Off
(Basically) On	Click	Off
On	Click 2x	FET Turbo
Ramp Configuration	[Wait for Single flash] Click N time for level N.	Selection of the “Low” you like best by clicking 1, 2, 3, etc. where 1, 2, 3, etc are different levels of low.
Ramp Configuration	[Wait for Second flash] Click N time for 1+Turbo-N.	Selection of the “Ceiling” you like best by clicking 1, 2, 3, etc. where 1, 2, 3, etc are different Ceiling levels.
Ramp Configuration	[Wait for Third flash] Click for how many steps you want in Stepped mode.	Sets Number of Steps.
Thermal Configuration	[Wait for First flash] Click for N times for N degrees C.	Displays Current Temperature.
Thermal Configuration	[Wait for Second flash] Click for N times for 30C + N.	Sets Temperature Limit.
Beacon Configuration	[Wait for First flash] Click for N times N seconds per flash	Sets Beacon Speed.

This is actually a simpler version of Andúril.  It loses things like Strobes and candle but adds (probably) easier access to most of the secondary things.

LED and Beam

There are some choices for emitters.  Here’s a list:

XP-G2 S4, Nichia 219C, XP-L HI, XP-L HD, SST-20 6500K, SST-20 5000K, SST-20 4000K/3000K 95CRI.

Those are some solid choices, but I went with the Nichia 219c option.  It’s 90CRI, 5000K.  If I’d known then what I know now, I might have gone with SST-20 in 5000K or warmer.  Still the Nichia is a good choice.

There are also secondary emitters.  I chose amber, obviously, but there are some other choices, too.  Here are all the choices: Cyan (the default), Amber, Green, and Red.

Here are beamshots for the stepped modes.

Tint vs BLF-348 (KillzoneFlashlights.com 219b version) (affiliate link)

I compare everything to the Killzone 219b BLF-348 because it’s inexpensive, has the best tint, and [probably] still available!

Random Comparisons and Competitive Options

There are a few newer lights that compare favorably to the D4S.  A couple by Fireflies – the PL47 (right angle) or the E07 are both good choices, and both 21700 lights.  21700 cells have approximately the same capacity as the 26650 cells and are probably as (or more) available as high current cells.

Conclusion

What I like

• Amber secondary!
• Build quality is great
• I like a larger light; 26650 is nice
• Ability to change level of secondary emitters through switch

What I don’t like

• No LVP
• Default thermal config seems to be a bit…. aggressive?  Not sure what else to call it.

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Notes

• I purchased this light with my own money at full price, for the purposes of enjoying a fun light. I was not paid to write this review, nor did I purchase it with intention to review.
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