Anybody tried the Warm White (>90 CRI) Luxeons?

With all the talk about Luxeon color rendering not being equal to incandescent, has anybody tried the Warm White series? LumiLEDs touts these as their high CRI product with a CRI of >90, compared to ~70 for their regular LEDs due to the lower CCT.

Re: Anybody tried the Warm White (>90 CRI) Luxeons

I seem to recall that the initial reports on these were that the QC sucked. Beams were splotchy and tint consistency was way off.

I believe that the only warm white parts available at the time were low-dome, and that was prior to the new phosphor application process, so maybe they have improved.

I think many don't like the idea of imitating incadescent light with a LED. General concensus is that the path to higher CRI lies with RGB dice in one package or some of the new work that's being done with UV die + white phosphor ala flourescent tubes. I seem to recall that the efficiency for warm white is pretty bad compared to standard white.

Of course, everything I've said is hearsay...

Re: Anybody tried the Warm White (>90 CRI) Luxeons

From my website, comes the following:

This is the long-awaited 1.2 watt "warm white" Luxeon Star /O LED, now being sold by such outfits as ledsales.com.au out of Australia. (They ship all over the planet, so don't let their location throw you off).

The /O means the LED comes with an acrylic optic, mounted to the Luxeon Star PCB using a cylindrical black plastic spacer. This convention follows other Luxeon products, so if you see a /O after its name, it comes with the optic and mounting cylinder already in place.
The optic appears to be a NX01 type, so the LED inside is probably a low-dome (batwing) type. The phosphor appears to be a light, slightly brownish yellow, rather than the light whitish yellow you might see in cool white Luxeon Star LEDs.

This Luxeon Star is mounted to a square MCPCB (metal core printed circuit board), rather than the hexagonal board that other Luxeon Stars may be mounted to. This board measures 1.0" on each side, and has two notches in opposite corners so that it may be affixed to a heat sink.


The color temperature is significantly warmer (yellower) than most other white LEDs, probably coming in at around 3,000°K. Overall, this LED has a warm, yellowish white color to it.
The brownish color at the perimeter was caused by the camera, and is not at all present in the LED beam. The camera does not always do well for beamshots, and here is one example.

Measures 164,200mcd with a test current of 364mA.
This measurement is consistent with what I know about the warm white 1.2 watt Luxeons.
The bin number on this sample is MP4JW.

Re: Anybody tried the Warm White (>90 CRI) Luxeons

[ QUOTE ]
idleprocess said:
I think many don't like the idea of imitating incadescent light with a LED. General concensus is that the path to higher CRI lies with RGB dice in one package or some of the new work that's being done with UV die + white phosphor ala flourescent tubes. I seem to recall that the efficiency for warm white is pretty bad compared to standard white.


[/ QUOTE ]
Ditto for everything you've said. While I certainly appreciate Lumiled's attempt to get better color rendering, my first reaction to the lower color temp was "why?" Perhaps to encourage initial adoption of LEDs for general lighting it might be desireable (to some anyway) to have LEDs which blend in with existing incandescents. However, since the eventual goal is to supplant incandescents (and eventually fluorescents) entirely the field should be wide open with regards to color temp. I've always seen LEDs as means to completely rethink how we light our world. I tended to think a warm white LED which seeks to duplicate incandescent was a little short sighted. After all, at typical interior light levels used in residences earlier experiments by Kruithof showed that any color temp from about 2700K to 4500K was considered pleasing and acceptable by most people. If anything incandescents tend to be on the low end of that and are either borderline or totally unacceptable to many people, including myself. GE's tests with the Reveal incandescents actually showed that about 85% of people preferred the higher color temp (~4000K by my eyes). Futhermore, the objections of most people to fluorescent lighting was due to the poorer color rendering and the flickering (on the older magnetic ballasts anyway), not the (generally) higher color temp. Making CFLs of mostly 2700K to 3000K also struck me as another misguided faux pas. Because of findings like this it made more sense to me to aim for something right in the middle of that range (3600K) or perhaps even towards the upper end. My rationale was that since LEDs would eventually be 10 to 20 times as efficient as incandescents, we could light our homes to much higher levels and still cut energy use substantially. At higher levels the range of acceptable color temperatures is higher. For example, at 500 lux the range is 3000K to ~7000K. The midpoint is right around 5000K. Indeed, I've long considered the standard Luxeon 5500K to be perfectly acceptable and pleasing for general lighting, provided that better color rendering is obtained. I believe all that sums up in a nutshell why quite a few here objected to the idea of imitating an incandescent with an LED.

I also second your idea that the path to higher color rendering lies with RGB dice in one package. In fact, if each color is independently adjustable this could lead to lamps with adjustable color temperature (and even colors if desired) via feedback sensors. That would make LED lighting universal for everyone, and let people adjust the color temperature to their own preference.

Re: Anybody tried the Warm White (>90 CRI) Luxeons

I not sure LD 1 watt warm white,3300k is brighter than pure-white luxeon or not. I have 1 watt and drive with 400 mA which seem to be orange-white. I'n not appreciate the warm-white light at all since the throw is seem to be not far as I think.

i have with great success. it all depends on what you're doing with the light. warmwhite for flashlight stuff no way.

but there's other uses. my first project was to illuminate my girls crystal display case. ordered a bunch of warmwhites, 3300 K, and stuff hooked it up and WOW! everyone loved it.

we then tried using 5500 K lux's and you end up blinding everyone. the color of the light is way too white with no color coming from the crystals.

everything has a place.

keitha /ubbthreads/images/graemlins/tongue.gif