Sorry, maybe this posted allready.
How hot they get after 10-20 min continous work
Hmm, hot?
They run at 25mA, that is ~75mA on the battery, on average 1.2V so 0.09W, of which 0.06W is heat. After 20 minutes the light may feel slightly luke-warm, probably not at all.
Any chance we can bump it up to 35 mA? The beam is more diffused than an E01 which means it’s really going to be difficult to use this unless in complete darkness.
Especially with the warm white at 5.5 lumens, I’m concerned whether this light will have any everyday use at all.
Would also like to know what’s the lowest battery voltage this baby fires at.
That would be an interesting add, if it will be a later option!
So far, I’m happy with the results and I don’t think this kind of light would need much more. It is what it is, it will serve for the designated purposes! I wanna stick a battery into it, forget it is there, and then, when needed, use it for the longest time possible.
I (colective “I”, meaning most of us) will - probably - have other lights to use with more output.
Thanks again for all the tests and work so far! BTW, I guess this light can also be used as a “thrower”: you throw it to someone’s head and…good luck to that someone’s head 
:smiling_imp:
You will have to accept that this light does not put out a lot of light, the current was discussed before and for sake of led lifetime and runtime of the flashlight it was (as discussed in this thread) decided on 25mA, as compromise between output and runtime.
You will be amazed if you have no other light than 5 lumens available how useful it is. One application, for me with its 60 degrees flood led it will be and ideal reading light without disturbing others around me who are asleep.
But search and rescue…no
I like the tests Sofirn has done, especially the rapid temperature change test (number 6) :THUMBS-UP: . An extreme version of this test would be if you did it the other way round (first cold, then hot): -35°C for at least 30 min, then immediately put the light in hot water that has just boiled a moment before (~ 90°C), I mean its a totally realistic scenario O:) , imagine you are working in the Arctic (or Antarctic) and forgot to bring a spoon, so you use your light to stir your freshly brewed coffee :D .
The lumen numbers (5,5 lm & 7,5 lm @ 25 mA) seem a bit below spec (the warm white quite a bit, the neutral white only slightly). If we were to increase the current to 30 mA we would get about 6,41 lm for the warm white and about 8,75 lm for the neutral white.
The question is if the slightly higher lumens are worth the trade-off in runtime.
At 25 mA and a power draw of 0,09 W from the battery (as per dijozz's calculation) we would get a calculated runtime of 10 h with a standard eneloop, a bit over 12 h from an alkaline and 20 h from an Energizer lithium.
At 30 mA and a power draw of 0,11 W we would get a calculated runtime of a bit over 8 h from an eneloop, 10 h from an alkaline and a bit over 16 h from an Energizer lithium.
Keep in mind these are only calculated runtimes, it would of course be great if Sofirn could do some runtime tests so that we have some proper data.
Would like to know that too, my guess and hope is that it will just keep draining the battery forever giving off less and less light.
I have told Barry that 25mA is what was decided on and that it is the perfect current for what this light is meant to be. We can keep discussing other currents but we had that discussion already and we will never be unanymous about it.
Perhaps Sofirn will come up in the future with a version with a reflector/TIR and high power SMD led, putting out 100-120 lumen, like all other manufacturers have in their portfolio also: more light, modes, less runtime, a bit less robust probably. But that is not this light.
Yes, 25 mA is a good choice/compromise for this light, both in terms of runtime and lifetime of the LED. The point of my calculation was more to show that you get very little extra lumens (only about 1 lm more) at quite a cost of runtime (roughly -20%, or ~ 2 h less).
Are colours decided? Definitively?
No, but the discussion about it is… :innocent:
Some explananation: there has been a poll in this thread about a limited amount of colours that Sofirn mentioned to me as possibilities. Enough people responded in that poll that I could communicate clear preferences to Sofirn (Barry). Apart from the few colours that the poll was about, a lot of suggestions were done in the poll for other colours that were not part of the poll. I have also given a summary of those suggestions to Barry. In the meantime Sofirn seems not so limited on the colours that at first were given as the only options, so the final colour line-up may be different than what came out of the poll. Also, in case many lights will be sold, more colours may be a possibility.
So in the end Sofirn decides on which and how many colours will be produced, and they have already received a good indication of what we at BLF prefer, so IMO that is all we can do about the colour situation.
I add this as a point of reference, not to try and change your mind. I carried a AAA Thrunite Ti-3 on a long backpacking trip as my only light source. I used it every night for my lighting needs. That light has 3 modes, moonlight, low, and high. Advertised output was 0.04 lumen, 12 lumen and 120 lumen. I don’t have a way to measure the lumens myself. When I needed that light, I used it ~80% of the time on firefly, and it was just fine. This was outdoors, so no walls for reflection and not completely dark. 20 days of lightning needs in the fall on a single primary lithium. I still have that same battery in the light and it still is shining when needed. It’s not my EDC, but it gets used on occasion.
I would think if you need a bit of light, 5 lumens will work. you won’t want to use it as a bike light, you won’t be able to see what goes creak in the night. But if you need to see something at your feet or close range, especially inside a building, it will function and always be ready. Especially if you equip it with a lithium primary.
You are likely correct, this is likely not the light you want for an EDC. AT least for me, running at 35mA would still not make it an EDC light for me. It is definitely not the light I want for an EDC, but I am interested in it for some special uses, like stashing somewhere with a lithium primary and knowing there will be a light there when I need it. Or by my bed for lighting up the room a bit without turning on the overhead light.
I had a Ti3 NW XPG2. The firefly mode would actually end up significantly brighter on a lithium primary.
Still, 5 lumens is not far off from some low or bright moonlight modes on other flashlights. For this type of light I think it is definitely sufficient.
CRI might not be the most important thing in this type of light, but the Yujis are just very pleasant to use anyway. It’s definitely not because we are addicted to high CRI. :innocent:
I actually still EDC an E01 and the 10-13 lumens it spits out are just about perfect for me. Firefly/Moonlight and 5 lumens and under sound great for the dark countryside or outdoors, but in my urban/suburban scenario, it just wouldn’t cut it. I’d still buy the torches anyway, but I’d rather buy them and use them than having them safe as shelf queens.
If 35 mA wouldn’t yield much of a boost in brightness then we’re better off at 25; that was some wishful/hopeful thinking on my part.
This is going to be a matter of personal preference.
I have a Yuji in a similar light that I measured at 23mA at the emitter when I made the swap, so direct experience with the same level of output as the Sofirn.
I honestly think it’s great for indoor use after dark, and in a emergency it would suffice for a wide range of tasks. It’s not what I would normally EDC, however, and when I’m doing tasks outdoors beyond just walking to the mailbox, I grab a higher power light.
Others may find it generally insufficient, and grab the higher power light almost much every time. I still think quite a few people in this category will find this light, especially at the planned price, interesting to use on occasion simply for how nice the smooth, floody, high CRI beam looks in situations where ~6 lumens is sufficient. In that case, maybe they buy just one, or one of each CCT, and are content with that.
Others of us use that light level fairly regularly (I especially do so indoors, late at night), or is an output reasonable for lights to stash in convenient places for unexpected uses or emergencies, as keychain backups for a larger primary EDC, or as gifts for others who might have such uses. This is the kind of person ordering multiples of these lights.
I refuse to use my Angry Blue Fenix E01, the Tint and Low CRI are total deal breakers, for me.
The Yuji High CRI LED is in a whole separate class, far above and beyond anything a Fenix E01 can compare with.
Comparing 5 lumens to 12 lumens is imho, completely irrelevant, when we are talking about a High CRI single mode light.
this Sofirn Yuji Light competes directly with the E01 w Yuji by skylumen.com
one costs $6 and is potted, the other costs $48 and is NOT potted… so No Contest!
imo, people who show up late to this thread, are being disrespectful to question the lumens of this HIGH CRI light.
Please do us all the courtesy of reading the entire thread, before bashing the lumen levels of this Sofirn light, or comparing it to a Low CRI Fenix…
If you cant take the time to read the thread, showing up as a johnny come lately, to ask questions that have already been addressed, is selfish and inconsiderate. At least read the first post, it contains some updates, and if you dont want to read every post, at least read every post by djozz.
I asked Barry to search for some extra lumens that may be blocked somewhere in the head of the prototypes and he is going to talk to the engineers. So maybe they find an extra lumen, maybe not. It may again affect the beam somewhat, we’ll see.
I have a few 3200k Yuji that bought awhile back. I put the Yuji into my solar garden lights. They throw quite far, maybe the reflector cause it to be more spread out. In total darkness, I think it will reach maybe 20+ ft. But I don’t what is the current draw the solar garden lights are pulling.
It sounds like you used the 30 degrees beam angle variant of the Yuji leds, in these lights Sofirn is using the 60 degrees variant, so way less throwy, the beam is really for close-up.
You can debate which beam angle would have given the most wanted beam but it seemed that the 30 degrees leds were not available when they bought them.