Which solder wire?
Generic chinese one from a long time ago…
It says “xinfa gao ji han xi zhi pin” :partying_face:
Ok… I’ll try to believe you 
It can be done with a lot more heat than with solder paste and with low melting point solder wire. My personal opinion that solder paste will be less stressful for emitter.
Anyone tried Sekisui 5760 under a non-isolated thermal pad MCPCB? It's pretty thin and it is said to work well.
Cheers ^:)
Djozz has had an underperforming blackie. After lengthy analysis he concluded that the reason for low performance was that led4power’s non-dtp mcpcb was the thermal limit.
This is a different setting, the area under MCPCB is way larger than the thermal PAD. So maybe the tape will work well. But I think there’s a large chance that it won’t.
Anyone ever used Black Flat in a C8?
I tried one today, mounted on dtp board and i find that it is almost impossible to perfectly focus the led in this host. The reflector lip just rests on the flashlight head so the reflector does not protrude down enough. I only got 124kcd with tail draw of about 4.7A.
Before you all ask, i went driver-less in order to be able to use dtp board for the led.
I haven’t done any black flat mods, but I’m happy to see more of them recently.
A copper shim under the MCPCB to lift up the LED is probably the easiest way to get your setup to work.
Focussing these small-die leds is almost an art!
Speaking of which, a few weeks ago I swapped the XM-L2 emitter in the following torch:
GearBest: https://www.gearbest.com/led-flashlights/pp_604347.html
Uses a smooth reflector into which the ∅16mm MCPCB is underside countersunk, using a beefy centering ring which sort of covers the emitter :!!!: dome. It is two plastic rings stacked, the above one of slightly lesser diameter. After swapping the emitter with an LH351C I had to deal with the centering ring, which I sanded down a bit from above where lesser diameter (this to let more light out) and from below to allow the emitter to sit more inside the reflector (had to glue the centering ring, of course).
It was all done quick with my friends at home and we having a :BEER: refreshing drink, and the result was a bit weird: the die of the led could be seen more or less squarely defined and enclosed by four flat isosceles triangles up, down, left and right at a very tiny distance leaving light gaps. My friend was a bit uneasy at first, though I said him a bit of a refocusing would fix the stuff. The beam is unusually consistent in hotspot to corona colour temperature, something very pleasing imho.
What could be the fixup in this case? Sanding down the centering ring even more from below to let the emitter seat even deeper inside the reflector maybe?
Thanks.
Cheers ^:)
This is a good idea, i might try it. I also i found out that even with the reflector all the way down the beam looks horrible, at this point the focus is decent but far from perfect, this led likes to seat very deep into the reflector.
I agree, especially when there is not much room to play with, like in the C8.
Did some tweaking on the C8, it is not perfect but still better than the 160kcd i had with the dedomed xp-g2 plus much better tint than the greenish one from the xp-g2.
So i was able to hit 196.000cd with what i think is fairly good looking beam, the hotspot is actually perfect circle but the corona around it’s a bit weird, probably the led is not centered perfectly.
Worst part about this was the fact that i had to sand down the head of the light in order to fit the reflector deeper into the head, after i did this sanding was required on the bezel also because the reflector sat a bit further and the bezel was not pushing enough to make a good seal with the o-ring.
So is this the best result? Probably not, but as i said it is better than what i had so i call this success given the fact that this is my first time playing with this led.
Sounds like a thorough Job, Bob! :+1:
I wonder…has anyone actually tried SSL80 in aspheric flashlight?
Yes, they are fun. The light extraction is higher than a wide-angle led of course (but not the throw), but most fun is that if the lens focal point is a bit above the led (in the cilindrical part of the dome), the flashlight has a very nice round fairly evenly illuminated hotspot.
The efficiency of SSL-80 leds is not great because it uses a very small die, I think it is 1mm2.
Thanks djozz. 
Did they throw? I don’t mean throw as well as white flat. Rather - at whatever output, is throw as expected for a flat 1 mm² LED? For a domed 1 mm² LED? Worse?
I’m surprised that the focal point is above the die. I used to think it’s a simple built-in precollimator lens. If that was the case, the focal point would be below the die.
Maybe it has some TIR at the edge of that cyllinder?
Got new Convoy 5A driver yesterday so I installed with Osram White Flat
3 convoy C8+ in the battle and all on turbo mode.
White Flat is the middle and it double the lux compare to Flat Black also hotspot is noticeable smaller.
XPL Hi is no match with Osram LED.
As a fan of HCRI LEDs, I really appreciate these tests! I would love to hear your thoughts on how these new Oslon 96CRI compare tint wise to the Nichias. IIRC, in one of your previous tests you mentioned that the
Oslons were less rosy than the the Nichia. The narrow emission angle of these newer Oslons remind me of the older Cree XRE so I’m guessing they will be relatively throwy.
These might work well with some narrow optics for good throw with minimal side spill. I’m of the opinion that for distance ‘throw’ lighting less side spill is better. The side can cause proximity, which can affect safety lights and anything that illuminates them. Here is the example Enrgtech.
Lighting with less side spill is less distracting and allows you to focus on brightness from a distance. Thanks Djoz!
If you are to stay here please remember to check out thread/post dates, bobfadi. This thread was created on January 18th, 2016.
Hi bobfadi, welcome to BLF.
Indeed these tests were done six years ago and numerous new types of leds have emerged since. But in general the same observation applies: the high CRI Osram Oslon leds are relatively greenish compared to high CRI Nichia’s. We have efficient High CRI Samsung leds now too, they are in between: not rosy but not as green as the Osram leds. Of course I (we at BLF) have not tested every led of every manufacturer but I still think there is a trend here (which must be a manufacturer policy).
For light with limited sidespill there is a choice nowadays of flashlights with narrow TIR’s instead of a reflector. They are my favorite for camping because they have the exact hotspot/spill distribution that I like (check the Sofirn IF22A). In contrast, my bikelight is one with a shallow reflector because here the spill is important to be visible to other traffic.
Thanks for joining the party, bobfadi!
