TK's Emisar D4 review

Its sure fun for 15s though :smiley: Seriously though, it makes for a great compact 18650 EDC light, nice useful beam but with a bonus of having a multi cell light output……….that fits in your pocket.

I thought in ways like that with the m43vn, 11k lumens short lived(30 seconds or so), but how many 11k lights that can be slipped into a coat pocket with ease. Still use 3000lm for long duration’s, but that 11k on tap if/when needed never grow old for me.

You wont regret it, it will become a fav in seconds………literally. In fact the problem will be on how many more to get :slight_smile:
Love these 2 lights, masterpieces imho

It’s a bit like getting a Zebralight SC600Fd Mk III Plus… only a lot brighter, with a more intuitive UI, available in more colors / tints, more mod-friendly, and on sale for 60% off. Just without quite as much runtime or a clip.

I wonder if anyone has tried a SC600 clip on the D4. It looks like it should be just about right…

Here’s some scope shots of the output. Measured optically OTF. Most of them links not to clutter the thread too much. Used a slightly discharged 18650GA and there probably was some throttling going on.

First on the 7135:
Moon

A bit above moon
A bit more
Almost there

71350 100%

Changing ranges:
Flashlight off

7135 100% for reference

Just a bit above
Just as specified, the higher range cycles between 7135 100% level and up.

Getting brighter

A bit more

Reaching some sort of a peak

Duty cycle increasing
Just a bit below turbo
Turbo

My D4 219c arrived today. Smaller than expected, 18350 may be small enough for EDC for me.
Can’t judge the output, the day is too bright. Still, after accidentally shining at my eyes I got 4 dots of afterimage for a quarter. With a half-empty battery.

You hid the most interesting scope pics… interesting shape at the beginning of each 7135 pulse, and rounder FET pulses than I would normally expect. Maybe this isn’t one of the FET models which slams closed hard at the end of each pulse, or maybe something is rounding out the curve a bit to prevent the ringing issues from older drivers.

Got my green D4 (219C) last night. The user interface is as nice as everone else says, and so is the heating up :open_mouth: Wanted to hotrod it further with XP-L2’s but changed my mind, I like it better with 219C SW353 R9050 leds.

And now I want another one for the XP-L2 mod :person_facepalming:

Played a bit with thermal regulation.
It’s less smooth than I expected, the output stays visually stable, makes a jump, stays stable for another while, jumps again etc.
Also, I noticed that if I heat it up a bit, turn it off and start at full output, the peak temperature will be much higher than originally. Also, I think it may be exceeding the level that I configured….or maybe my burnt fingers got more sensitive :wink:

If you set the temperature by switching the light off when you feel the max temperature has reached, then the actual temperature at the sensor (inside flashlight) is higher, as there is a temperature difference, or “delay” with the surface. So from a cold light when you engage turbo, then the max temperature you feel should be similar, but when you go to turbo from a warm light, then the max temperature you feel should be higher. This holds true for steady state max output/temperature at about 600-ish lumens as well; this temperature will be higher than what you think you have set.
At least this is my take on it.

Edit:

The higher the temperature increase rate (dT/dt), the bigger the difference between desired maximum temperature (what you felt), and actual max temperature value (Tmax set by D4).

General note: I find blinking very bright. Even during the day it can hurt the eyes.

I guess you’re right. Idea for future improvement: Do the calibration twice to make sure it starts with a warm light. Or do it with far less than 100% output, so the effective delay is lower.

What’s the recommended way of adding GITD to this light?
Has anyone found a matching GITD o-ring? How about a glow paint?

A word of warning. Just noticed there was a 6.3mm metal shaving peeling off the positive end of my 18350 tube. Gladly noticed it before sticking in a battery. It was sticking inwards a bit so could have possibly shorted the plus and minus, since it was longer than the distance between contacts on the driver end (3mm).

My 18350 tube had that too, maukka, the shaving forms where the threading ends. I did not think much of it, just pulled it off, but you are right, there is a possibility of things going wrong if you are not observative and unlucky.

This killed Lexel’s Klarus G35 driver for the review or not? [Review] Klarus G35 supplied by Banggood, partially review as I killed the driver

Ok, it wasn’t a piece of metal from the Emisar D4, but from the G35 I presume, hehe. :smiley:

Buy a sheet of gitd foil. Then you can cut two stripes around 3mm wide and stick them around the inside of the light. There are two flat walls where you can stick them to.

TK yes he is screwed.
He needs also a soda can light.
Fuzzylogic have checked out the Q8 thread?

Just a pic to compare it to the S42. The D4 is superior in all aspects but one: USB charging.

But that is quite a big one for me though, a future version of the D4 with USB charging (and regulated maximum modes that temper those modern low Vf emitters a bit) certainly would be an improvement for me, even if that adds a few mm of length.

@djozz
it seems the S42 could be as short as the D4. There is a long tripod thread in the tail of the S42

I know, and the driver with USB socket and components probably eats extra mm’s too.

Got a link for the gitd foil?