Emisar D4S review

Thanks, I just ordered it. Your reinforcement sounds like a good idea. It also sounds like you might have a nice workshop there.

Right there with ya girl! When mine gets here… I have a stack of XP-L Hi in 5A3 that are going in! I love the 5A3 tint, I do wish the 5A4 could be had… but have never seen them.

Just FYI, I got in touch with Mountain Electronics and sent them a video of my problem with the light. They said it looks like the 7135 may have died and offered to repair it. Thanks ToyKeeper for your responses. Given the choice between mechanical failure and user error, I generally lean towards user error (as in I did something dumb). LOL.

I see your list, and the bin codes seem loosely related to the Kelvin temp, but then I see FW1A at 4000K and FW3A also at 4000K as well as 3500K. Then there are combinations: FW3A & 1D, FW3A & FD2, etc. I find all this confusing; not sure how to interpret it. I’ve seen some graphs/charts but my poor vision finds them a bit confusing and hard to read. Does a particular bin represent a Kelvin range? You talk about 5A3, 5A4 which clearly means something specific to you, but, unfortunately not to me.

FW1A, LH351D 4000k (second favorite)
FW3A, LH351D 3500k
FW3A, SST20 FD2 4000k
FW3A, Nichia 4000k sw40 r9080 (favorite light!)
FW3A, Cree XP-L Hi 5A3
Emisar D4V2, SST20 4000k
S2+, XM-L2 T6 4C

Any help, so that I can see the basic principles perhaps like a basic “primer”, will be much appreciated, especially if you make it relatively simple. If that is too much, then any information at all. I googled the subject, but didn’t get a clear understanding of it.

It’s difficult to explain without a chart of the bins and what each one is. This chart shows the bins used by Cree, and I made it clickable so hopefully you can zoom in to see detail if necessary:

The SST-20 and LH351D emitters use different names for the bins, but they are still pretty much the same aside from the name. Also, both of these have a conspicuous hole between 4000K and 5000K, which is unfortunate. Basically, they are missing the entire series of “4” bins Cree makes in the 4500K range.

Nichia emitters seem to use a different binning system, so they’re harder to translate.

Thanks ToyKeeper. That’s a great image that I can see very well. I appreciate the time and effort you took to answer my questions. I can remember back to the days of the “Luxeon Lottery”, when today’s LEDs were not even imaginable.

This bin chart is about tint and its relationship to Kelvin temp. Is there a separate chart for intensity?

Not really. The candelas-per-lumen value depends on both the LED and the optic or reflector it’s used in. The total candelas also depend on the particular model of torch and the battery. So it’s complicated.

Generally though, just check the flashlight’s specs and do a little math. Many have published values for lumens and for candelas, and that’s often enough. But if you want a better idea of how throwy the beam is, divide the candelas by lumens and it’ll approximately quantify the beam shape. A bigger number is a narrower but brighter hotspot, while a lower number is wider and less intense.

Thanks, that’s informative, but I should have said lumens instead of intensity. Are there bin ratings for lumens, and are they combined with tint bins? Sorry for all these question; I usually Google the subject before I ask but often find the answers unclear or over my head mathematically.

Bin ratings are what gives you brightness rated by the manufacturer at a certain current.

Tint bins are different: they give the tint of the LED light output.

Thanks. These types of ratings are helpful, although only the last three include Kelvin ratings. Ideally ratings should include Kelvin, lumens, candela, brightness/tint bins, and CRI. Personally, I’d be fine with just lumens, candela, and Kelvin.

_*Model: EMISAR D4S
OTF lumen output and candela at start-up
XP-G2 S4 : 3300lm / 40,000cd
Nichia 219C : 3000lm / 20,000cd
XP-L HI : 4300lm / 45,000cd
XP-L HD : 5100lm / 27,000cd
SST-20 6500K: 4200lm / 58,000cd
SST-20 5000K: 4000lm / 55,000cd
SST-20 4000K/3000K 95CRI: 3000lm / 41,000cd**_**

Go into the field for which you can choose your LED and tint.

You’ll see way more info.

Higher CRI = usually lower brightness bin, and lower lumens.
Higher CCT = usually higher brightness bin, and higher lumens.
Smaller optical LED die= more throw(SST-20 is the smallest, so best throw)
No dome = XP-L HI (second best throw behind the SST-20)


I just received the Trustfire 4”–6” holster. It is much too narrow to fit the D4S. I tried other 26650 lights; none could enter the holster, even when applying force. However, it was a perfect fit for my 18650 lights. Is it possible you were referring to the D4 rather than the D4S?

Nope. Fits the D4S just fine


It’s the 5-7” one that works:


OK, that is what it said when I placed the order, but when I click on it, it says 4-6”
In an event, it is the one I showed in the pics

2 of TrustFire Nylon Flashlight Holster Belt Durable Holder Case for 5”–7” Flashlight Adjustable Tactical Torch Cover for 18650 Flashlight Models T3 T4 E3R A8 Z9 Fenix UC30 UC35 E35 Surefire G2 6P E2L

OK, no prob.

Here’s a shot of the holster I posted about earlier with a D4S in it: