Fireflies ROT66, Born for fans of flashlight

Just got up, cold UK morning the ROT66 returns 4280 lumens at 4.07v, just warming the old girl up to 4600!

Weird.

Vf of most LEDs has negative temperature coefficient, this means LED current will be higher as temperature increases when DD driver is used. More current means more lumens.

It seems to peak at around 4.10v, I let it cool and fired it up at 4.10v and it was still 5000 lumens, it was 4500 lumens at 4.20v cold

My D4S records 4400 at 4.20v and 4600 at 4.17v from cold, Is this normal?

I was hoping the high CRI would reveal the Predator earlier

I just received my Fireflies that I ordered on the last day of the GB. I still haven’t received the one I ordered before the GB.

Here are the results measured with the TA Lumen Sphere calibrated with Maukka lights.

Champagne host 219B 4500k 9080
4650 lumens at 0s
1482 lumens at 30s
Dims at about 17s

Black host 219B 4500k 9080
4500 lumens at 0s
3991 lumens at 30s

Edit: The champagne host was tested with fresh off the charger VTC5D and the same cells were then used on the black host so that might have accounted for some of the lumen differences at 0s.

I tested the Champagne host twice and it steps down at about 17s. It doesn’t do that on the Black host. Anyone have any idea why that is?

The tint is super nice. It’s the best looking tint I have seen to date. I was afraid it might look too magenta as some people have commented on the 4500k 9080 but I’m so glad it is not magenta at all, just some pink/rosy. Even on turbo, it’s not as rosy looking as what you see in the pics. It’s very white at the center of the beam. On the lower modes, it is just neutral white and perfect.

I compared it with all of my other lights that looked neutral tinted before and now they look ugly yellow/green.

That’s how it starts. After seeing a truly good tint, nothing else will ever look quite the same again. And now you’ve got a lifelong affliction, because unfortunately this condition is terminal.

My sympathies.

Despite I don’t agree with your perspective on lumen measurements, I enjoyed your video. The comparisons were excellent. :+1:

We won’t stop until we use purely pink lights, because any hint of green is disgusting!

Here are some tint pics I took the other day, with the ROT66 Nichia included. White balance was set at sunlight, so the 5700k Jaxman E2 will look the whitest to the camera, though it’s pretty close to what I saw with my eyes subjectively.






It’s too bad there’s no substitute for this discontinued gorgeous 9080 tint. I’m thinking if we can get the SST-20-W FA1 bin, it should look about the same as the 219b 4500k 9080 but more powerful. Also the Samsung LH351D T1 bin should be similar too but no 80+ R9.

None of you are making it any easier for me to resist this light.

I’m guessing it’s the normal variation in the uncalibrated temperature readings between different ATTiny chips. Perhaps the one light of yours reads low, and the other reads high.

For comparison, I just checked my D4, which has been sitting on my desk, turned off, in a 22° room for plenty of time to be at the ambient temperature. It reported 34°.

If the light thinks it’s warmer than it really is, it will step down faster.

Have you seen Maukka’s numbers with the 4000k variant of the LH351D using a minus 1/4th filter? They’re pretty nice.

I’ve seen lots of good things from Nichia’s E21A R9080 emitters as well.

Problem is the minus green filter takes reduces lumen output by 17-20% if I remember correctly and it makes the light look weird with the pink sheet.

E21A format is hard to use

Fireflies want me to send my broken XP-L version to Vinh or solder a new LED in. Neither options are viable.

Keep testing them, mine read anywhere from 4400 to 5700 depending on heat and voltage.
There might be turbo reset issues.

Maybe temperature calibrations are different? What are temperature reading? (double click from battery check)?

Like was said earlier, the thermal protection may be kicking in way too soon on the champagne model. Try manually setting the thermal limit. I’ve got a video on it if you don’t know how.

Rumor is Fireflies might be making an SST40 version (replacement for XPL-HI?) I don’t know much about the SST40. My order for an XPL-HI is on hold until they figure out the problem. A possible offer/solution is an SST40 version. (nothing concrete or confirmed at this point) Thoughts?

SST20?

The SST-40 is a 5050 led where the current one is 3535. So they’d have to make a new mcpcb. That seems unlikely. If true though, it’s a nice little led. Warmest color is 6500K and it has really high output.

Yeah, SST-20 is 3535. It’s die size is closer to XPG3 than xpl at 2mm^2 so output might be closer to the Nichia version.