Cree Easy & True White Technologies

[neutralwhite]

hello, :thinking:

when are these Cree EasyWhite & TrueWhite LED Technologies coming out?.
which flashlights will they be in ?, or am I way behind?.

I have the PD32UE with a 5000CCT.

would these new LED's be better in easy / truewhite?.

excuse my daftness....:sigh:
thank you.

 

[neutralwhite]

what is the latest 5000CCT in XML

XM-L T6?, as in my PD32UE?.
U2, U3?. L2 L3?. what is all that?. which ones latest?..:whistle:

is there something after even XM-L now?.
i see this cree easywhite and truewhite stuff on the cree site.

its all confusing this....or am I confusing myself more like?!...lol.



thanks.

 

[BigRiz]

Re: what is the latest 5000CCT in XML

First of all, T6, U2, U3, etc. don't say anything about colour (chromacity). They're efficacy bins - the larger the number means more lumens from the same wattage.

The chromacity bin you're looking for is probably 3A, 3B, 3C or 3D (all of them would look good and are close enough to the 5000K you need). Look at page 7 of this document which should help you understand CREE chromacity bins better: http://www.cree.com/~/media/Files/C... Modules/XLamp/Data and Binning/XLampXMBL.pdf

btw.. now there's a 2nd edition of XM-L named XM-L2

 

[neutralwhite]

:poke: thanks....:wave:

 

[BigRiz]

btw I should have said "chromaticity" not "chromacity" but too many T's get me confused :D

 

[Anders Hoveland]

Update:
Cree LED lighting has now become available. The local ymca has even installed Cree LED troffer luminaires in one of the rooms, which use TrueWhite technology, so apparently these things are just beginning to become prevalent.

I wanted to make a comment about this. I have a Cree luminaire, 3500K, 92cri with TrueWhite technology that I got for experimental purposes. The luminaires in the ymca are a whiter 4000K. I have been looking at the spectra of the light through an improvised diffuser grating (a common computer CD ). There is a noticeable difference in appearance of the spectra between the 3500K and 4000K. A distinct red line is clearly visible in the 4000K, whereas the red is all blended in the 3500K.

Now we all know what the basic concept of Cree's TrueWhite technology is. It uses an LED which emits a greenish-white color light, and a separate red LED emitter, both of which combine to make a "true white" tinted color of light. This gives higher efficiency, and a higher CRI as an additional plus.

I think the phosphor being used for the 4000K TrueWhite LEDs is more green-shifted than those in the 3500K TrueWhite. The 3500K TrueWhite phosphor presumably is more yellowish, which explains why the red line in spectra is covered up. (I can just barely discern a brighter reddish-orange line in the spectra)

Of course, the phosphor used for the greenish-white LEDs in the 3500K TrueWhite is no doubt more green-shifted than standard 3500K LED phosphor. (standard Ce:YAG LED phosphor can be either more orange-shifted or more green-shifted depending on the dopants added in the crystal structure)

I have never been able to find a spectral graph comparing the different color temperatures of Cree TrueWhite technology. I had previously just assumed they were using a standard greenish phosphor, and just using a thicker layer of it over the blue LED emitter, depending on the color temperature. And then adding more red LED light for the lower color temperature options. Apparently this is not the case.

which flashlights will they be in ?

I do not think you will be seeing TrueWhite technology used in many flashlights, if any. The main advantage of TrueWhite technology is higher efficiency, because in normal white LEDs energy is lost in the phosphor conversion to red light. For lower power applications, it's just easier and simpler to use all-phosphor conversion. Using two separate colors of emitters could also lead to light mixing issues, which would affect the appearance of the light beam (the color on illuminated objects would not be entirely even).

 

[Anders Hoveland]

Also, I wanted to add my personal observations of the light quality from a Cree TrueWhite fixture.
It emanates a light with the same aura as a fluorescent (a little harsh on the eyes), but things do look a little more colorful. Skin tones look good, unlike with lower CRI LEDs, and the light feels a little "fuller".

As for color rendering, reds are more brightly illuminated, but not really saturated with a deep hue. Deep orange colors can appear a little reddish-shifted, and red colors can appear a little salmon-tinted. In other words, the color differentiation between red/orange is not really the best.

I have the 3500K version, and it does still make colors look a little white-washed, like a fluorescent fixture. The difference between them, however, is that the TrueWhite does a really good job rendering orange and yellow colors, and also blue colors look a little more vibrant, at least those with royal blue [indigo] hues. Yellow colors definitely stand out from a white background, more than under fluorescent lighting.
(what I wrote may have seemed contradictory about the rendering of orange colors, but it depends on the object, different colored objects may have different types of pigments)

The 3500K TrueWhite did make green colors appear just a little yellowish, had a little trouble rendering deep forest greens, but this may not be the case for the 4000K and 5000K versions, since they are using a more green-shifted phosphor, as I stated in the previous post.

Overall, I would say that color rendering from the TrueWhite is basically similar to what one might get combining fluorescent and standard LED illumination together. A little more colorful than just standard LED or standard fluorescent fixtures by themselves.

I got the Cree TrueWhite just to evaluate the type of light it gave off. I have to say, however, that a 95CRI 3000K LED seems to have better overall quality of light than the 3500K TrueWhite. It's a matter of degree, but the 95CRI LED feels easier on my eyes (no doubt because it is using a 10-20nm longer-wavelength blue emitter), the reds look more saturated, and blue-greens also look just a little bit better.

 

[Anders Hoveland]

I also wanted to make one more comment/observation. I have observed Cree TrueWhite fixtures at three different locations, and the room lighting appears so much better in the daytime, when there is just a little natural light from a skylight or window. I am not entirely sure why this is. Maybe someone else can corroborate this observation.

So yeah, Cree TrueWhite works much better when there is some natural light coming into the room also.

 

[evgeniy]

Also, I wanted to add my personal observations of the light quality from a Cree TrueWhite fixture..

Nice review.