Very well said sir.
Exactly, with 50,000 lumen torches floating around people don’t really how useful 0.05 lumens is.
Firefly is get dressed without waking the girlfriend setting and it’s my most used on my Manker E01 on my keys. Plenty of light to walk around in the dark with.
This light is actually brighter than I would like for domestic use!
I don’t care what year it is, 5.5 lumens is still pretty useful and the last thing I would want is to boost output and sacrifice runtime and longevity. If you want the world’s smallest, brightest (you know for 10 seconds before stepdown) flashlight, look elsewhere.
Sofirn is making exactly what was requested, a high CRI Fenix E01 like light and from what we have seen so far, they’re doing a damn good job at that.
Nice to see Sofirn’s tests, thanks to Sofirn for making them and to djozz for posting!
Yes… +1
I’m an engineer, we’re conservative 
I like knowing my designs will meet spec, even if the component properties vary substantially from one batch to the next.
Map reading comes to mind - a distinct possibility in an emergency.
High CRI light can be extremely helpful for distinguishing the many colours used on a high end map. I have the UK’s Ordnance Survey maps in mind here - pretty much the de-facto standard for outdoor activities in this part of the world.
First aid might be another possibility, but I’m less sure of that one. Map reading is the application I have actual experience of.
I’m happy with those results, I’d put it straight into production on that basis
Those lumen figures look about right, bearing in mind that datasheet lumens are captured using a 360° integrating sphere, including light that goes in less useful directions. You never get all of the lumens when you actually build it into something, because of unavoidable effects like reflector losses.
I actually argued for 20mA, not 25mA, but those results suggest that 25mA was in fact the better choice, so well done there 
I can live with 25mA from a component stressing perspective, because it still leaves a 15% margin from the 30mA rated maximum.
No harm in trying, of course, but I think they’ve got everything they’re likely to get. The light’s looking good already :+1:
My personal reaction? No way, no how. If they make it more than 25mA, I’m not buying it, simple as that.
This is intended to be a last-resort light that works no matter what. I know the normal BLF perspective is to… ahem… “seek out the limits” of the LED but if you want an electronic part to last, you need to run it well short of the maximum rating.
As I noted above, the datasheet maximum is 30mA, with test results provided at 20mA. In the datasheet world, that’s a fairly heavy hint that designers should work to 20mA, but you can push it harder if you must, subject to things like potential reductions in reliability.
35mA would probably kill the LED in fairly short order, and I wouldn’t want to think about the likely effect on the high-CRI phosphors, either.
Sofirn used the 60° beam angle variant of the LED, because the 30° version wasn’t available from Yuji at the time (see quote from Djozz, below). Using the 30° LED would probably boost apparent brightness a lot more than pushing extra current through the LED, and it would have better long term reliability.
I plan to buy 4 of these lights, and I’m happy to buy them with the 60° LED, but I’d definitely buy another 4 if Sofirn offered a version with the 30° LED later on. Once I’ve tried them out, I expect to buy more of these lights to store in various places, and a 30° version would most likely become my favourite.
this post discusses the fact that the $150 McGizmo sapphire also uses the 60 degree Yuji.
so the Sofirn not only beats the Fenix E01, and the SkyLumen E01, it even beats the McGizmo Sapphire, on price at least
What other light besides the Sofirn Yuji, have we seen videos of being thrown out a 3 story building, working in a block of ice, working after being hammered out of the ice block, and run over by a truck, plus working under water?
well… there IS this Wet Sapphire shot that the Sofirn has not done yet, but this light is not even Turned On!:
Im pretty sure the Sofirn w Yuji could get Turned On as a necklite too 
Who cares??? 
I don’t think Yuji has ever offered their 5mm LED in the 30° version through their web store. I’m pretty sure it is a version only available upon special request, presumably requiring the buyer to purchase an entire production batch, which is likely a lot more than 1000 emitters.
Not to argue for increasing the current, but just to provide confidence in what we already have: djozz and I have both independently verified the LED can survive at least 90mA for short periods. djozz also did a 24 hour lumen maintenance test at 50mA.
He saw an 8% drop in output over the first 30 minutes as the LED’s under test warmed up, and then basically flat output for the rest of the test, which is a really good initial result.
In my test, I ultimately pushed the LED to 160mA, which definitely did damage the LED. Another user in that thread also took some awesome spectral measurements up to 50mA, verifying the CRI and tint are pretty consistent up to that level.
Overall, it looks like Yuji has rated these LED’s fairly conservatively.
Must……resist….inappropriate………jokes!
Ummmm….is this a family friendly forum? :smiling_imp:
That’s also AAA sized?
Thanks
is the final design of the light decided yet?
By definition of what a prototype is: no
As B cells are not available, I am guessing a small c cells
Same here.
I have created quick survey about 30° version . Hope you would like to help Sofirn to determine the interest in it.
Here are results so far
We don’t know that. Let’s ask Barry about it.
You can hold a survey for anything, but fact is that this light has a 60 degrees led, and those will not by magic turn into 30 degrees leds. Sofirn has bought 2000 of them and sofar the interest list is 673. I doubt that there will be a new batch of these lights soon, and if that moment comes it is to be awaited if they can get their hands on 30 degrees Yuji leds that time around. But more likely even I see it happen that they will make a batch with common cool white 5mm leds that have a bit more output which will appeal to the general crowd and not just flashaholics.
My thoughts, precisely!! :+1: At least for this light, that survey is not needed!…
The things that remain to be seen, as far as I remember, are the host colours and the poll has been made as well!
The extras - such as a diffuser - were talked about, not sure if it will advance or not, but at this phase it is not essential.
I didn’t want to change a bit in this light. I’m happy with it as it is.
I created the survey just for information purpose only. It will be Sofirn decision if and what they gonna do anything with this information.
You started a poll in this thread which is about this group buy light without mentioning that you apparently are targeting the results for a future batch, you can not blame me for thinking that the aim was the current batch so I responded like I did.
Of course I do not blame you and I would react probably the same
I should mention about the survey that this is for Sofirn information only, not to change this light.
Hopefully they will consider results for future batch.
Sorry for confusion I made. 