Greetings everyone ! I found this forum thanks to djozz’s excellent tests and joined to ask this question…
I’m building a big ceiling light using Yuji VTC LEDs (2700K+5600K). Note this is not a flashlight…. it’s got about 6000 lumens of each color temperature. So far I’m very happy with the results, but I would like the option to have a lower CCT for that warm cozy feeling later in the evening. Not all the time, as the Yuji LEDs are awesome at high power, but at low power it feels like some warmth is missing.
I’ve tried adding a red LED strip and this gives pleasing results. I’m using a dual channel bench power supply to power the 2700K Yuji MCPCB modules and the strip, so they are independently dimmable using big convenient knobs. Right now I think it’s a bit too red. although it certainly is nice and cozy. In this mode I don’t care much about CRI or color fidelity, more about how it “feels”, rather I’m trying to approximate something like candlelight, or the light from a fireplace.
I was wondering if it would look better with very low CCT “white” LEDs, but haven’t been able to find any that have proper specs. I’m trying to avoid blue light in the evening in order to get better sleep, which seems to work very well. I’ve been sleeping a lot better since I got rid of the old CRI80 blue-pumped LEDs I had before and put the Yujis up there on my ceiling, so if I put some 2000K “white” LEDs I’d really like to check the spectrum first to make sure they don’t have a blue spike.
Or maybe I should try a different shade of red, maybe “super red” or “hyper red” or “marijuana growlight red”?…
Anyway, if anyone has advice to offer, thanks in advance!
I would definitely take a look at Nichia E21A 2000K, because maukka measured it, and it does not have a blue spike (nearly no blue emission at all). Clemence is the most known seller for this LED, take a look here:
I think, this is by far the highest quality ultra warm white light source.
For some other applications, Cree XP-E has HE Photo red centered around 660nm, and Far red at around 730nm; and XP-E2 has phosphor corrected (PC)-Amber but those won’t approximate any of the natural fire spectrums.
Thanks, I’m not interested. I want a soft light with large area, not a point light. I should have said so. Also the color temp is not what I want.
I really should have emphasized that I’m building a soft light, sorry about that. I’ve got lots of low-power LEDs arranged in an array, adding only a few high-power LEDs like this one would create uneven color and thus colored shadows.
I can’t find the spectrum, but the other luminus line in this range seem to have a very large blue spike…
This LED looks quite good.
I like the spectrums posted. Now, if this one was easier to buy pre-mounted on a MCPCB
This would be a very nice LED to put in existing lightbulbs as retrofit though. This would be nice for some of my existing lights. Gotta think about it, thanks!
The red strip I’m using right now doesn’t specify a wavelength, so I’m going to assume it’s the most common, around 625nm. I can get 660nm LEDs from OSRAM and also the Cree’s you mentioned for a quick test. I’ve never seen a 660nm LED light. Does it look very different from a standard 625nm light?
You guys got me thinking, I could actually use a cheap 2000K strip with a 500nm filter in front to get rid of the blue. That could be a convenient solution.
You can order the LED soldering service as well. Board choices can be VR16SP4, VR21SP4 and VR21P4 depending on your needs. Take a further look, and message Clemence, if you want to proceed with that
The Luminus 1616 1800k 90 CRI mentioned by staticx57 seems to be having virtually no purple, and even less blue, than the E21A 2000K, but the latter has deeper red by having an emission peak at ~644nm vs ~635nm readed from the graphs. Probably the Luminus 1800K will look still very deep red.
I’ve asked them for more info about the spectrum, which is not given in the datasheet. If I order some of these, and you are interested in testing it with your spectrometer, I can mail a section of strip to you.
for not realizing Yuji sells a 2200K strip with their BC LEDs on it.