Fireflies E07 preview

Very interested, but I want to see output and throw. It’d be complementary to the rot66 (which I just ordered) because I can EDC it.

Needs a very high current battery as well :slight_smile:

I’m not so happy with the led choice, no XPL-HI 5D and no 219B. I wonder what would be a better mod, mixing three 3000K and four 4000K Samsung LH351D’s or seven Luxeon V’s.

USB charging is a gimmick which rises the cost and is prone to failing, don’t do it.

It should be possible to turn off the aux boards through the ui.

Copy the switch design od the D4/D4s couse it’s pretty well done, on the ROT66 it’s difficult to find the switch. But on the render I see something is done about this.

It would be extremely nice if a wider (widest) frosted optic would be available to buy separately.

A big big :+1: for using Anduril and the 21700 format. Hope Emisar will catch up because this light i way more interesting then the D4S imho.

I agree 5D/5A is one of my favorite tints and looks just as nice as 219B 9080 except for color rendering. Mixing cct would be a great option because the resulting tint looks amazing from what I’ve seen.

USB charging is not a gimmick. Some of my friends who are interested in these high power flashlights, but are not flashlight hobbyist like us, are only interested in buying flashlights that have built in usb charging. I help them buy lights like the TC20 and DN70, which they only use USB to charge. I also like to have usb charging for just-in-case eventhough I never really use it.

One of my most favorite lights is my 2014 DQG EDC Triple 26650 Flashlight with the XP-G2 R5 4A. This new E07 is nearly identical in dimensions and won’t have the really irritating 2 second hold to turn off the light :person_facepalming:

Hey, FireFlies, please include a strong magnet in the tail and the ability to set the intensity of the aux leds. I want the aux leds bright enough to use as a night lite, just like the ones in my Emisar D4S.

I have yet to purchase a SST20 4000K light. I think this will be my first one. Looks good!

I received 2x 21700 40T’s
Just waiting for suppository duty in my ordered PL47, and this one when available. :smiling_imp:

This light will be pocket king.

I just realize the weight is specified at only 138g, which is even less than the Emisar D4S that weighs 142.0g. Very disappointing considering this has 7 LEDs and D4S has 4 LEDs. This light will be another hand burner like the original D4 which cannot maintain any useful lumens due to poor heat sinking. I hope Fireflies add at least another 40g to the head otherwise it would be a waste of a potentially great pocket flashlight that could also serve for practical use.

Yea, fill in the USB charging you love so much with a thicker shelf and scrap that. Done. :slight_smile:

40g will add just mere seconds of turbo time and won’t do anything to sustained output.
Myself I prefer lighter. And with charging.

The D4S vs D4 is night and day difference. The Sofirn C8F also kicks ass in sustaining output compared to the D4S. Even if the extra mass doesn’t add a whole lot of turbo time, it can at least sustain the lower outputs far better.

D4S also more surface area than D4. Extra mass will only add like 20 seconds to turbo runtime, what you’re really after for heat dissipation is surface area. The 7x emitters will have a very high turbo output yes, but what the sweet spot here is more efficient lower outputs. It won’t be able to maintain 1000 high cri lumens with perfect regulation like the ROT66, but probably more along the lines of 400.

With a 1.5” head, I think it will be too big for pocket carry anyways outside of cargo pants and/or jackets, so a slightly chunkier body probably wouldn’t hurt, but I wouldn’t want to make it too bulky and/or sacrifice usb charging.

Please describe the heating difference in detail Sofirn C8F(18650 or 21700?) and D4S.

I like the adding mass idea. And i agree that surface area is also important. I built a heat exchanger gadget to cool my laser and to create more surface area all i had to do was add more cuts in the aluminum. I was working with 1/2” Al, stock and what occurred to me as i was fabricating, was that each cut i made added surface area —more access to air to remove heat. If i just kept the 1/2” x 2” x 4” block i would have roughly 22” of surface area, but if i made a cut perpendicular to the 4” side i add roughly 1 7/8” of surface area per kerf/ slice.

So, for my gadget, the aluminum absorbs heat from water thru copper tubing and a fan runs blowing air thru all the nooks and crannies removing heat. Note: i have no scientific evidence to support this hypothesis, just gut and instinct. I think i am right—but i dont know for sure.

Point is, i suspect the 4 or so fins they have milled in the prototype picture may be increased to effectively double and triple +, the surface area—more contact area with air, less heat. Also, i think i found information suggesting copper was a better conductor of heat. And depending on alloying of the Al, the copper seems stouter than the aluminum in my opinion.

I would add a picture to show what i built, but dont see a way to attach local files, from my phone.

Nice!! Interested!!

I just took some lumen measurements at 1s -> 30s -> 60s
D4 XP-L HI 5D (62.8g) : 3,310 -> 1,009 -> 250
D4S XP-L HI 5D (142.2g) : 3,577 -> 3,210 -> 2,670
C8F 18650 (195.2g): 3,170 -> 2,870 -> 2,820
Measured weights exclude battery

The feathery weight of the D4 obviously perform much worst than the other two, while the C8F is the most stable. At 60s, the C8F feels the coolest to the touch by FAR. Also although I agree surface area is important to allow heat to convect into the air, it is really only important for sustaining lower output. For sustaining turbo output, heat sheds way too slowly through convection compared to the heat gain, therefore we have to rely primarily on mass to absorb the heat to extend turbo run times. Also even if you increase surface area by adding fins, it will not really speed up heat loss through convection very much under still air. I remember seeing turbo runtime data of the D4 copper head vs aluminum head that shows the output is maintained much better with the heavier copper head.

C8F has the best design for handling heat from high output. The majority of the mass (74.2%) is in the head. The size and surface area of the head of C8F and D4S is similar. However, C8F head weighs 144.8g while the D4S head weighs only 75.0g. This is why the C8F head feels mildly warm after 60s whereas the D4S feels much warmer.

This is the reason why I am concerned about the light weight of the E07 because with 7 emitters pushed by high amp 30T cells, it can create much more heat than the D4S and C8F. Hopefully Fireflies can add more weight into the head, such as by thickening the shelf for the mcpcb. Will not add much to the cost but greatly improve performance.

Nicely done. Scienced the s#!t out of that.

D4: 16g/emitter
D4S: 35g/emitter
C8F: 65s/emitter
E07: 20g/emitter
E07+40g: 25g/emitter
A major weight increase that you propose won’t bring it anywhere near C8F in Turbo time. If stock D4 has 10s turbo, E07 has 12.5 and E07+40 has 15.5.

That’s not perfectly correct, head weights matter more than full lights. And E07 even with 30T will drive its emitters less hard than the others.

But anyway: unless the light has a lot of resistance this will be a D4-style hotrod and extra weight won’t change that. If you don’t like it, it’s probably not the light for you.
D4 was a very divisive light. For many it was the light of the year. But it received lots of criticism for what it was - the hottest hotrod out there. I believe E07 will receive a lot of sympathy from those who loved D4. And lots of hate from those who didn’t.

Fireflies could have made it with 4 LEDs, there are suitable lenses available at about the same diameter. The light would become like 2 mm longer and much cooler. But I guess being much cooler was not the point.

Why I asked you, my research C8F (18650) at an air temperature of 24C grieved me:

- in 990Lm mode. After 20 minutes, the head temperature reached 58 degrees.

  • in 650Lm mode. After 25 minutes, the head temperature reached 54 degrees.
    I think the design lacks cooling fins and more. In version 21700, added cooling fins, but I think need more.
    It was interesting to compare with other studies. And I wonder how the Fireflies E07 will show

TBH, I’d be just as happy with this using 3 emitters, 4, 5, 6, or 7. As long as it has decent performance at ~1000 lm and below, the brighter modes are mostly just a bonus. I’d rather have less weight instead of more turbo.

If it ships with Anduril, it’ll have a relatively sane ceiling by default, which should help a lot with not overheating. But turbo is still there for quick bursts.