Even worse than the amount of blue light is any source of lights that switch on suddenly in front of the eyes at night,
Like motion sensor spotlight 
I guess I’m a bit insensitive 
I hate when they are brighter than my flashlight 
. At least, sensor lights should slowly (1 s) ramp up so you’ll have a chance to focus elsewhere.
You’re blessed.
I liked when swiched on ,CFL bulb increased bright gradually was pleasant near bed
but they took too long time to arrive at max.
Does there are a sort of fast auto dimmer (1-2sec.) on modern Led bulbs
Or similar to put on wall box for inca. lights?
Never seen a bulb that does this. I’d buy it if it has as additionaly three mode UI.
If you find an external box, let us know.
There is a thread dedicated to the blue light topic that would be a better place for a detailed continuation of this tangent.
As a couple brief comments, though: I second djozz’s observation that the spike shown is very typical. For example, in the top part of image here is a spectrum of a 4500K Nichia 219B (from Maukka’s Fireflies ROT66 review) of the same color temperature. It’s very similar in the location and relative scale of the peaks and valleys:
https://i.imgur.com/g2HKhcQ.png
I’ll leave off my other thoughts on the topic, and simply note that based on the research I’ve read: if in doubt, there’s certainly no harm in erring towards lower light levels as the first priority, lower color temperatures as the next priority, and high CRI as a final priority to reduce blue light exposure. However, I have not seen research that indicates the typical narrow spike is worse than the more spectrally distributed but similar total energy of blue emission in an idealized black body.
Got the 32K-CEX today. What a nice surprise they are very rosy. Love it.
Left: C01, right: Tube.
Thus far, closest to the Yuji. Tried all LEDs in the pack, tints do not vary much, which is also very good.
Posted this on reddit a week ago or two, but here's what's in my collection. In the case you're wondering about it, yes, all the emitters in the picture here are at least R9050/R9080.
Hi rngwn, what is your standard shipping method? It looks like ePacket is currently the only option for Australia - is it a reasonable cost?
The same to U.S. and Canana, $10. Not the cheapest, but fairly reasonable.
How about direct driving these at 3.2V with a LiFePO4? Are we talking instant death, or a decent but reduced lifespan?
LiFePo cells start off at 3.6V fully charged, that will push enough current through these leds to kill them (see the current/output/voltage graph in the OP)
Could I put a resistor in series with the battery to bring down the current? My shaky understanding of Ohm’s Law is thinking that about 150ohms would be about right?
22 Ohms would do just fine. With fresh cell, it will drive the emitter at 45mA and less as the battery are being used up. Still, if you can afford to do it, a buck converter or at least a linear regulator is recommended to keep the LED drive current constant.
Thanks, I’m a complete noob with all this. I’m going to get some C01s to play with, but I also have some old 2AA minimag hosts, and some plastic AA dummy cells that would take a resistor soldered across the inside really easily.
Unless you can suggest any kind of buck converter with a diameter less than 14mm that I could just put in series? Maximum simplicity is the idea here…
Sure, for the low currents that 5mm leds need, a resistor in series is a perfect way to regulate the current (for high power leds you needs more fancy ways of regulation if you want to maintain more or less constant output). 150 Ohm seems rather high, but you can experiment, you may end up with 10 Ohms or less.
I’ll bet they can be safely used direct drive on two Eneloop or any 2 NiMH or NiCad cells, or two primary 1.5V cells of choice, like button cells or alkaline (but not 2 Energizer Lithium), also probably fine direct drive with a single primary CR123A or any size 3V primary.
Just got mine today, 3400k and 4500k. Ordinary shipping took 13 days to the UK. Well packaged, ESD bags. All good.
PM sent
So far I have had not trouble using Yuji 5mm LED’s direct driven from 2 x AA alkalines or 1 x CR2032 lithium coin cells.
rngwn’s LED’s are even more robust than the Yuji’s, and I also have several of them in 3xLR44 button cell lights.
Voltage drop under load for all of these options seems to keep the output pretty reasonable.