Before maukka started offering his lights, this spring I had an exchange of a couple of lights with him to check his calibration against my djozz-lumen (the djozz-lumen I found two years ago already 9% high when at TLF-meet-up re-measuring a couple of lights that were measured before in the Led Lenser sphere in Germany).
The calibration difference between maukka and me was different for a neutral 5000K 70CRI Nitecore P12 (djozz-lumen 7% higher than maukka) and for a BLF348 with 4000K 90CRI 219B V1 (djozz-lumen 11% higher than maukka). I have not found yet where the spectrum difference comes from (could be a few causes).
For the ROT66 numbers I substracted 10% from the djozz-lumen to correct for a high CRI Nichia that is a bit higher Kelvin than the BLF348 that read 11% high.
Driving me mad now, it’s reading 4600 tonight with fully charged Sony VTC5A x 3 and VTC6 x 3, down 1100 lumens on a few days back, but if I click off then go back to turbo I keep gaining 50+ lumens or so each time, the hotter it gets the brighter it gets at turn-on.
4600 at 4.20v 25c
5200 at 4.10v 40c
It doesn’t increase Lumens as it’s running though, only at turn on. My other lights aren’t doing it. My XP-L has a busted LED and the 219b seems to have output issues.
I wonder if the springs are expanding with increased heat giving reduced resistance or something. Ever so slightly loosening the tailcap reduces lumen output too.
Oh yeah it sets shop alarms off from 50m away too!
(I filmed it)
I’m filming it against the Noctigon M43 219C 80CRI and the ROT66 makes the Noctigon look unbelievably green. The D4 219C 80CRI stands up ok though, whitish subjects look super accurate.
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.
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.
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.