I have to wonder how difficult it would be to do something similar to what they are doing with the led filament bulbs that have popped up recently https://www.youtube.com/watch?v=H_XiunR-cAQ
ahh, ok thanks!
Excellent spectrum!
It's for VTC 5730 led's or for lamp ? What spectrometer you used ?
Anyone use Yuji BC Series High CRI MCPCB LED 24V Modules ?
Evgeniy, you asked where that spectrum comes from.
Go back up the thread to where I posted that spectrum, originally (not the copy you reposted)
Click on the one I posted, and it will show you the page where the image comes from.
It’s their spectrum from their web page, I did not create it.
(when you post an image link using the little “sunset” icon above the text entry box, it lets you first post the link to the image, and then optionally post the link to the source page, that ’s what I did there)
(I do sometimes post spectra I captured using this: https://publiclab.org/wiki/spectral-workbench
Thanks. (Image removed from Yuji site, 404, but found by web.archive.org.)
you use Yuji led modules ?
Odd, I got to that page earlier this morning.
Nope, curious about them but not up for ordering stuff I don’t know much about.
If they had something like the Luxeon PC Rebel Amber with a bit of phosphor added to improve color rendering, that would be interesting.
But “no blue_ is what I’m mostly looking for that’s hard to find.
Interesting tidbit — even blind people who lack rods and cones still respond to the blue range by having their body clock reset, among other responses:
That spectrum does look good: http://www.yujiintl.com/packages/high-cri-led-test-reports-candle-white-5630
“candle white” would be an apt description of that light.
The 1900K leds are interesting, but not in their webstore unfortunately.
You can wrote to Yuji managers. May be, Yuji has some 1900K .
Let me see- I might have some 1900Ks. I bought a bunch of 6500K and (another) Violet pumped die and can’t remember if it was the 2700K or the 1900K… they only had them in stock for a few weeks.
Sorry, it’s 2700K VTC. I just found the order number in the inbox… under HIGH CRI Web Store, not Yuji.
After long discussion with Yuji manager I received next answers :
If I want buy modules with VTC led, now available only 3200K modules, only constant voltage, or any other - but you must request (and pay) 50 pcs [modules, not led’s] each type (2700,3200, 5000, 5600K, constant voltage or constant current).
Yuji really want sell it ?
The european pendant to Yuji would be Ledon:
ledon-lamp.com/en/led-lamps/led-lamp-a60-7w-e27/
Most lamps have CRI 90.
90CRI is something within the range of most led manufacturers, Yuji is somewhat special in that all their leds are 95CRI+. Osram has a 96CRI led range, but it is generally very uncommon.
I tried to find what leds are inside the Ledon bulbs, but they have managed to hide that from the internet very well…
You can find some pictures of the used chips here:
fastvoice.net/2014/07/28/im-test-die-erste-integrierte-led-leuchte-von-ledon/
fastvoice.net/2013/12/21/im-test-neue-led-spots-von-ledon-von-sehr-klein-bis-sehr-hell/
fastvoice.net/2012/09/19/jetzt-gewinnen-ledon-sunset-dimming-led-lampe-dimmer/
fastvoice.net/2012/08/23/ledon-sunset-dimming-sensibles-erroten/
fastvoice.net/2012/05/15/led-splitter-dimmer-ledon-rotlicht/
futurezone.at/produkte/energiesparlampen-sind-tickende-zeitbomben/24.580.939
I would love to test a set of 95+ CRI bulbs, those have to look great!
thanks for the links, angerdan, i enjoyed reading some of it 
. It seems like they produce their own leds/modules, but might source the led-dies elswhere (somewhere the USA is mentioned).
Ledon Lamp was sold from Zumtobel to the austrian entrepreneur Thomas Lorünser in 2013.
So the do have some know-how.
Zumtobel Group - „LEDON Lamp“: Zumtobel Group steigt ins LED-Lampengeschäft ein
Zumtobel Group - Ledon Lamp macht sich selbständig
They did buy LEDs from Cree in the past, but not for all lamps.
The lamps has been produced in several countries:
Vermutlich handelt es sich um ein Gemeinschaftsprodukt der LEDON-Fertigungsstätten in China, Großbritannien und Österreich
Die Komponenten werden in Österreich und England mit LED-Modulen aus den USA vorgefertigt, in China zusammengebaut und dann als komplette Lampen wieder nach Europa geschickt
I have 95CRI 10 watt PAR20 Osram/Sylvania bulbs in my office and kitchen. They put out 550 lumens (more than 50W halogens). Three years ago they were $30 each. I did have one (out of 16) of the bulbs die. It was in the same socket where halogens tended to blow after a month or two (usually taking out the $35 Lutron dimmer in the process).