Thread: Neo900 - finally a successor of N900
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wpwrak is offline wpwrak
2016-03-06 , 15:53
Posts: 79 | Thanked: 719 times | Joined on May 2014 @ Buenos Aires, Argentina
#2770
Originally Posted by jetmarc@hotmail.com View Post
Ok I did this today, and this is what I got.
Thanks a lot, this is great data ! A question about interpreting the color temperatures:

Code:
 Ambient = 11168.9 Lux, CCT = 5675K (Delta E 9.687946)
 Closest Planckian temperature = 5403K (Delta E 8.488890)
 Closest Daylight temperature  = 5517K (Delta E 4.974792)
I realize that there is a lot to know about light that I didn't even know I didn't know ;-) Of these three, would "CCT" (approx. 5700 K) be the one that corresponds to the CCT parameter of the LED ?

In the L130 series, we get to choose between nominal CCT values of 5000 K and 5700 K (or values further out). Each also comes with fairly large tolerances, e.g., 5500 K would still seem to be within the "best" tolerance bin of the nominally 5700 K LED.

The color binning is shown in figure 16 of
http://www.lumileds.com/uploads/461/DS209-pdf

Code:
 Color Rendering Index (Ra) = 70.1 [ R9 = -37.7 ]
I'm very happy about this one. I had been a bit worried about the CRI, since the best we can get at 5700 K is 80%, and I wasn't sure if the "missing" 20% would be a problem. But this is actually even one step better than the original then.

Code:
The last command also creates a plot image: base64 -d > plot.png
Thanks a lot ! The curve does indeed look like the 5700 K curve of the L130.

Again, thanks a lot ! It's always better to have solid data to rely on than guesswork, no matter how sophisticated.

- Werner
 

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