TK's Emisar D4 review

Hard to tell what’s optimal, but that is definitely an option.
What it DOES NEED is active cooling of some sort, so it can maintain an output of at least 2000+ lumens indefinitely.
Make it as small as possible and don’t forget high CRI.

I really like your idea. I always though that 3x18650 fit much more comfortably in the hand. The number of emitter I leave it to the experts, but 3x3 is 9. Sort of like an in-out burger (for those who don’t know their best seller is a “double-double”) so maybe a triple triple is what is needed for the Goldy Lux light. (pun intended)

I have always thought that 4x 18650 light were just a bit large to actually want to carry (sure it can be done) but out of our flashlight actual carry minutes what percentage is from 4x18650 lights? My hunch is it is out in the long tail of the bell curve.

Not my idea Mr. Ronin. This light will see daylight soon. How soon, that we don’t know yet. This light is the D7, and will be presented after the D1S IIRC. 3x18650 with 7 emitters it is, yay. :partying_face:

Yes But,

Better quality, (DQG) seems to have issues from what Ive read.
Why so small, just a bit longer and maybe real cooling fins and the light does not need to be throttled back.
more emitter choices, it just kills me to buy a new light and then spend a bunch of money and effort to go and change the emitters. better to pay for that up front but only once.

So yes A DQG but with Zebralight/Hank Build quality. Super well thought out (and responsive revisions) TK software not trying to be smallest (why do that?) I say shoot for most usable aka the light we grab whose use falls under the big part of the bell curve. And while I’m at it, in a real sand/earth tone (not gold or almost gold) color.

Rant end

Whew…

Dear Mr. Noob, (LOL)

I see you know how to say the right things to the boys :beer: but how do I know your not just a tease?
Like they say, photos or it did not happen. But If Hank said that a D7 was in the works, now that would be interesting. and is the rumor of 3x18650 settled or is a more moderate/carryable 26650 light possible (Or is that a D6) Part of my reasoning for the 26650 is greater size/weight flexibility. With a sleeve or different tube (yaaa custom tubes like the D4) we can have a light that could run 1x 26650, 18650, 18350, 18500, 14500, 16430.

So the light gets designed with just “enough” mass/fins (seems like the D4 might be a nearly perfect light but short on mass/fins to really use the HP under the hood) and then choose your power/weight configuration of the day.

It depends on the timing and whether the driver was in sleep mode when power was disconnected. This is entirely an analog circuitry issue. If the MCU’s charge drains far enough, it will reboot (which counts as a battery change). If it doesn’t drain far enough, it won’t notice the tailcap was loosened. The firmware can’t do anything about that.

After using Crescendo for a while, I kinda want different actions to ramp in different directions. Like… hold to ramp up, click-then-hold to ramp down. But that wasn’t something I changed in the D4. It’s something which will have to wait until I have a completely different code foundation written to make multi-click events easier to process.

Also not something I changed. It was spec’d that way. My preference would be that momentary mode is permanent so the only way to exit it is to disconnect power. I’d also prefer that it use the memorized level instead of always doing turbo. Maybe in some later UI.

On a FET+N+1, I’d probably want a reference blink at both channel boundaries. Also, some other input mappings. Like, I prefer battcheck on four clicks.

I suppose I really need to get that new code written. It’s relevant for several projects now, and I’ve been … distracted by other shiny things.

Yes, though it’s a mess. Look in the crescendo directory. I was originally doing this for crescendo before the D4 thing happened.

Nice. I wonder if RMM might be able to stock something like this. Ideally I’d want something more like the Olight Baton clip, deeper-carry than the B205, but the B205 seems to be the best fit for the D4 out of the ones listed on that page.

Nope, its arms are too wide to fit in the clip groove.

That would be a very helpful type of measurement to have during development. I mostly just had to go by feel. :slight_smile:

Take another look at Zebralight’s pages for the recent SC600 models. For example:
http://www.zebralight.com/SC600w-Mk-III-18650-XHP35-Flashlight-Neutral-White_p_173.html

It’s a slightly bigger light, and its highest mode without thermal regulation is 312 lm. So, I’d say the D4’s ~600 lm steady state (at a moderate thermal ceiling) is pretty fair. If you want it brighter though, you can still set the ceiling higher or give it a better heat sink. It’s funny to watch what happens when touching a block of ice to the D4. Even just getting it wet makes a huge difference in the level it stabilizes to.

Some are trivial, others are not. I’m working on some new code to make all these things trivial, and to make new UIs easy to create, but it’s not ready yet.

Maybe I’ll call it “Mostly Harmless”.

Hmmm…not if i put a grinder to it…

After getting the different current readings on my 20700 fitted D4, I changed it up some. The tube threads at the head are pretty short, so I moved the copper spacer to the tail end and made the necessary adjustments for it to all work. Now, with a better ground that is consistently repeatable, I’m seeing 17.6A out of the freshly charged Sanyo NCR20700B cell. This allows for 3915.75 lumens out the front, at start. The 219C is a greedy emitter, it’ll take whatever you give it, up to a point.

I charged up and tested one of TomE’s Sanyo NCR20700A cells, wow! 21.14A at the tail for 4391.85 lumens from the Emisar D4 with Nichia 219C emitters. Yowza! Do it get hot? Is it noisy at Mardi Gras? :smiley:

That’s basically how the thermal calibration mode works now.

The sensor is not at the emitters though. The sensor is behind the MCPCB, the shelf, and an air gap. Its measurements are rather lagged, which is the main reason it’s difficult to steer. Putting the sensor directly on the MCPCB would make things much easier.

Yes.

That was nice. :slight_smile:

Would potting the driver/ cavity with silicone help thermal calibration?

Infrared thermometers are cheap and good for various things, like cooking. For longer range measurements, look for a bigger distance to spot ratio. Otherwise 1:1 ones can be had for a few bucks shipped.

https://www.aliexpress.com/w/wholesale-infrared-thermometer.html?site=glo&g=y&SortType=default&SearchText=infrared+thermometer&CatId=153709&initiative_id=AS_20170813211613&needQuery=n

Thanks for the reply on the SC600. Mine is the Mk II cool white, so H2 is still around 670. No matter though, thanks for the confirmation. Still this D4evil is impressive.

yay my own D4 finally came, waiting over the weekend was bad at least the wait is worth it. :wink:
This things heats up nearly instantly just crazy, the light output is kind of underwhelming first and it is daylight here so i cant test it outside then i ran ceiling bounce test it was at least twice as bright as my Astrolux S41 wow!, i guess the eyes perception doesn’t work in linear manner.
This flashlight is really small i cant imagine it is being that small until you have one in you hand. I like the plain tube, with all the flashlights available in the market this look different and feels smooth, and the green is also beautiful i didn’t regret it. Cant wait for the sun to sets.

I meant that they had little impact on overall user experience, not that they were easy to implement.

My initial daytime impression was similar. It just looks better when it’s dark. Maybe because it is so floody?

I am sure it will, what shocked me the most is the heat generated. wow!

Can’t overlay the output on the video, but here it is on the graph.

Interesting how fast the VTC6 cools down because of the immediate stepdown and the Aspire just keeps getting hotter because of less thermal mass with the 18350 tube. I’ll probably measure the temp for a longer time to see where they stabilize.

Now, I can’t be sure which one of my seven Aspires I used on the thermal image, so it might not be the same one. Here’s two of the best samples compared and even they differ greatly because of different internal resistance.