TK's Emisar D4 review

Great review of a great light TK :THUMBS-UP: .

Hank, we want:

From off:

• 1 click : turn on in last used mode.

TK, doesn't press and hold already start at the lowest mode setting?

These look awesome!!! :+1: :sunglasses: :+1:

When will they be available for purchase?

If those are prototypes and the design is still open to changes only things I’d suggest would be knurling on the 18650 battery tube and maybe some kind of raise ring around the button to reduce chance of accidental pocket activation.

For a ramping UI, something like DrJones lumodrv worked fairly well. Lumodrv had the following UI:

  • long click from off - minimum power, then starts ramping up.
  • Short click from off - last used mode
  • Click and hold from on - ramp up. Repeat to switch the direction of the ramp.
  • Double-click form off or on - turbo
  • Triple-click from off - 20%
  • Hidden strobe modes - ramp all the way to max, then continue holding for a couple seconds to access strobe modes.
  • Momentary mode - ramp down to min and continue holding. Light enters momentary mode (disconnect battery to exit).
  • Single click from on once light has been on 2 seconds - off

Lumodrv was almost perfect. But a few changes would be nice:

  • Ramping should set a memorized mode which could be accessed from a short click from off. This mode should not be overridden by using the moonlight or turbo shortcuts.
  • When clicking and holding to start in minimum power mode, it would be nice if the light paused for 1 second before starting to ramp up.
  • Turning off the light from on requires the light to have been on for 2 seconds. That is a bit long. Change to 1 second.

Yes, it does. That’s why I want a single click to go to a memorized mode instead — it doesn’t need two shortcuts to moon.

The D4 already does both of these. I think the timing is slightly shorter in both cases though — about 2/3rds of a second.

Another small update:

Protected cells likely won’t fit. It looks like the maximum cell length is about 67 mm.

I wanted to try an old protected NCR18650A for lulz, but it’s too big. So, use unprotected cells or short protected cells (with a high amp limit, at least 15-20A).

Dang! I can’t wait to get back home from this trip to start using my new D4 that Richard has sent! Understanding that I’m at the beach for a week oughta tell you that I’m excited to get my hands on my nichia/green light.

Thanks for all the info and for your thoughts. I’m not so worried about not having memory. I use my lights at all sorts of levels from very high to very low and not exactly knowing if I’ve last used it for reading and not disturbing the wife at night or used to to check for skunks at night when taking my pooches out to do their business could lead to some confusion.

All in all, this appears to be a high-tech and well thought out light for a very nice price. $35 is quite a bargain for all this performance (and cool looks to boot!).

That’s right! :sunglasses:
And this is just the D4 with 4 emitters… Can’t wait for the D7… :smiling_imp:

A little flashlight 1 on 1:

Green tint = bad
Green light = good

I think I’m gonna call it the Little Hulk. :smiley:

I did some thermal tests. Details in comment #1.

Short version: It gets too hot, because it takes too long to reach a stable state. I’ll be fixing that.

Hi TK, made some comments to your reply on RMM thread which I probably should have brought here instead, re: TM being non existent as far as I can tell.
I leave those there and delete them I guess in a couple hours to keep R’s thread clean, I don’t think he would interested to hear of any issues right now, or none issues, not sure really,
I know when I should turn down a light due to heat … ha ha ha, ouch…

Sorry, but i had to:

I vote for the middle one.

I was wondering TK if a video of that huge drop from Turbo to moon in 5 seconds or so would be of any help.
Is that considered defective, should I say something to Richard about this, I’m certainly able to make the light do what I want it for but wondering what he will tell others if they start asking, or maybe you can tell him and it would be better explained I imagine.
Really just an opinion of course but the only light that would definitely benefit from T.M. and mostly for safeties sake and the inexperienced customers would be that XPL’s, that light gets very hot very fast,
I also agree that last mode mem would be another fantastic feature, have found myself now just double clicking to turbo and then ramping down to my comfort level.
Let me know if a vid helps any, I’d be happy to do that if that’s helpful in someway.

I’ve only heard of one light doing the turbo-to-moon thing. I’m not sure if it’s a design issue or a fluke.

Please, measure the driver space.

More updates:

This is what the shelf looks like under the MCPCB. It’s covered in thermal goo:

The driver comes out with a bit of force from the inside, and it still works afterward when held in place only by pressure. Here’s what it looks like:


To get the driver out:

  • Unscrew and remove the bezel.
  • Pop the optics out. Hopefully it isn’t glued to the MCPCB, but if it is, this step could be tricky.
  • Unsolder the red and black wires.
  • Pull the MCPCB out.
  • Carefully push on the driver with a plastic rod like a spudger.

To get the driver back in, you may need to file down the edges of the driver a tiny bit. I did, because the glue around the edge made it slightly too wide.

The driver is 22.3 mm in diameter.

The shelf under the MCPCB is 4.5mm thick. :+1:

I think it may be giving me the finger, to protest being separated from its home.

Good news about the anodizing. I accidentally scraped part of my light with a bastard file while filing the edge of the driver, and after wiping the driver dust off I can’t even see where I scraped it. So the anodizing seems pretty tough.

Also, Narsil works on the D4 without any code changes. I flashed NarsilM.hex from the repository, and it just works. Moon appears to be significantly lower, too — about the same as my ZL SC52, or 0.1 lm. I haven’t actually measured it yet, but it looks pretty close.

However, runtime on moon isn’t dramatically longer. The driver seems to use about 4.5mA even without the LEDs on, so the absolute longest it could possibly run is about 28 days on a 3000 mAh cell.

I did a very low-tech runtime test to see what the curve looks like and make sure LVP works. To speed things up, I used an 18350 cell and did not recharge it first. I measured the output at 285 lm in my light box, then moved the light over to my runtime test setup. Note, the battery was not full; I had been using it since the previous evening and I think it was at about 3.9V or 4.0V. It didn’t really matter for this purpose. I also bumped the table a bit during the test, which made some small bumps in the graph.

What this shows is:

  • LVP works. It goes directly to moon in one step though, instead of doing a more progressive step-down.
  • Output on this mode, which was about 350mA on the 7135 chip and 350mA on the FET, has a gradual decline as expected.
  • I was too impatient to wait for the light to turn off completely, so I ended the test when I noticed it had stepped down to the lowest level.

My “test setup” was pretty ad-hoc. It looked like this:

Could you measure d and h of
the cavity in which the driver is located, please?

Thanks, TK for the detailed review !!

Fully agree !!
Figure, you’re using it during the day, meaning you need a fairly amount of light, but want to turn it off and on several times, you would always need to pay attention to release the switch at the desired level. :frowning:

Although I really prefer non-memory most of the time, I appreciate being able to optionally activate memory.

Of course, flashaholics probably will have (at least) one light with and another without memory. :wink:

Great review TK.
I must have a green one with 18350, it’s so cute.

Nice green. Shame it’s all glued. Looks nice though…

Cell ground goes to the driver trough battery tube end?

Does anyone know if this one will be available elsewhere? Shippingcost is making this less interesting for me.