[Available again! - BLF special edition light] new Sofirn AAA twisty high CRI 5mm LED

Excellent! I’ll be interested to see the results.

This sort of light is something I’ve been keenly interested in for a while, so I’m glad to be able to help. I also very much appreciate you and slowtechstef moving this project forward, as well as anyone else who steps forward as tasks come up. Offhand, Jon_slider took initiative in getting information from Fenix, and TheShadowGuy has offered to help with polls.

I’ve got my master copy of the list in Excel, so I can check for duplicates fairly easily, and if changes to how the list is formatted are desired, I should be able to do that, too.

Moving it to the first page should be no problem if shared access if figured out. Otherwise, slowtechstef can either link the first post to the list on page 10, or manually re-copy and paste the list as it is updated.

I need some information from Barry for this story to be correct and it is night over there atm.

There was some talk about getting “extra” LEDs several posts back. Is that even remotely a possibility? I’m thinking of doing a DIY photographic ring light, with tint mixing. I would like to buy maybe 100 of each tint, or even more, but I can’t afford 1000 at their price! Not saying it isn’t worth the price. I’m 100% certain it is worth every penny. I just don’t have that much money. :cry:

Results of the Yuji high CRI 5mm led tests.

While doing the output/current tests of the 3200K and 5600K version it became very clear that these are different leds, not just a different phosfor. Then I took a closer look and the build appeared slightly different too. At first that made no sense to me, the difference should only be the phosfor. But then I remembered that the 3200K and 5600K batch were purchased with 2 years in between, 3200K in January 2015, 5600K in May 2017, so in between Yuji had changed the design (for the better, as seen in the test) So most likely the 3200K leds in the new Sofirn behave like the 5600K led in this test, apart from the tint.

For the test I thought it would be fair not to cool the leds as well as possible but simply solder them on a common FR4 board, so the heatsinking would not be too different from how the led is mounted inside the flashlight.

Here are the output/current tests:

Directly after the test the leds and led wires felt luke-warm to my lips, nowhere near hot.

This chart already shows that the chosen 25mA is a very conservative current, at 50% or less of the maximum possible output and 30% of maximum current, while most of my flashlight builds are 80% of max output or more.

But to get a hint at longterm stability I soldered the two leds in series and did a 24-hour runtime test at 50mA (so double what the leds will get in the flashlight). Here are some voltage and output numbers of the combined leds in series:

0 hrs 6.43V 29.9lm
5 min 6.37V 28.2lm
30min 6.35V 27.6lm
2 hrs 6.37V 28.0lm
3.5hr 6.38V 28.0lm
10hrs 6.39V 28.3lm
16hrs 6.35V 27.5lm
24hrs 6.38V 27.7lm

So, nothing exciting is happening here, the leds are fine and show no signs of fading. So unless led death is a sudden event without performance warning, also 50mA is a fine current for these leds.

AFAIC, the suggested 25mA drive current for the flashlight is a nice careful current.

Thanks all for all the input about things I do not know much about, like jon_slider and Noir for info about potting and Noir for driver info. Especially the driver info I will communicate literally to Barry because it is stuff I do not understand myself and hopefully the Sofirn engineers do understand it.

Djozz, thanks for sharing your test. Useful data like this is great to see, especially seeing the improvement both in output and Vf.

I’m also glad to see your test has a good match to a similar test I did with a 3200K purchased in the last 6 months. I can’t measure lumens, but I did see intensity peak at 90mA, with Vf around 3.2V. Here’s my results (along with another user’s CRI data further down the thread):

Even better, you have lumen maintenance results that I have not attempted. It looks like there was a small drop in output over the first 30 minutes as they warm up, and then fairly stable for 24 hours.

That supports a separate plan I have for a little personal project driving 9 of them in parallel at 350mA - as long as I don’t get too much current hogging due to variation in Vf or voltage drop in the wiring.

I hardly ever visit CPF so I had not seen your nice test before, very nice that my result matches yours, and I see that the assumption is correct that Yuji changed to a new make of led between 2015 and 2017.

djozz your test is nice, but it doesn’t show how hot the emitter gets on the inside and how its life expectancy is reduced. I would not overdrive them.

No, it does not show that, that is why I called the 50mA test just a hint at longterm stability. Sofirn is going to use 25mA for the AAA twisty which is within the specifications for this led (30mA maximum continuous current).

So, at 3x rated max current, it still gave ~63lm/w efficiency. :open_mouth:

Now I KNOW I need a source for a couple hundred of each tint!

Interested in:

1 3200K
1 5600K

Interested in a neutral white one

Interested in:

1 3200K
1 5600K

I don’t know much about flashlight LEDs, but it seems like you have a HUGE variation in the performance of the two 5600K LEDs. I know the planned drive current is around 25mA, and the variation there percentage wise is not as large as 90mA. But just seeing a 50% variation if Vf at the same current, and a 4x variation in lumens at the same current, makes me think the LEDs are terribly inconsistent, or you have some sort of a test setup issue causing the variation.

Not saying this to be critical, but my observations. Thanks for running the tests, I know it takes a decent amount of time and resources to do something like this.

Sbslider, that’s not actually two separate 5600K emitters. djozz plotted the lumen output as a function of the current of a single emitter as the dark blue line, and the forward voltage as a function of current for the same emitter as the light blue line.

So it’s not a test of consistency between emitters, although the result is consistent with a test I did separately.

Hope that makes sense.

:person_facepalming: Guess I should have read the legend . . .

thanks for the clarification.

Interested in:
1 3200K
1 5600K

Sign me up for 2x 3200K please.

EDIT: can natural HA III colour be an option?

I’m pretty sure that Sofirn does not do HA III coating, let go on a 6 dollar light. I guess that their silver flashlights are anodised but not to HA III.

Convoy’s have a nice clear coating but I know that Simon is keen on good coatings. But still I doubt it is HA III

interested in 3 of each tint probably