Best CRI from current LEDs?

moses

Enlightened
Joined
Apr 6, 2001
Messages
515
A bit curious if anyone know the best CRI rating from the current crop of white LEDs? wondering if they are ready to replace full spectrum lights. Currently, we are using Solux for our study rooms. These are the lights that some high end museums use to give close to sunlight spectrum and are far better than 'daylight' imitating fluorescents. The problem with Solux is the low efficiency - hence my LED question.

Thanks!
Moses
 

2xTrinity

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Dec 10, 2006
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2,386
Location
California
As of right now, most white LEDs are only using single-phosphors, meaning they are badly deficient in red. There have been 98CRI 2-phosphor LEDs designed in labs, but not are commercially available, and the efficiency of those particular LEDs is unknown.

IMHO the best thing to do now for color rendering is to augment several high-efficiency white LEDs with a single high-powered red LED. That fills in the gap in the spectrum and really makes the color rendering nearly perfect (at lest subjectively to my eyes, I don't have any tools to measure CRI formally). The problem there is that it is very difficult to blend the beam evenly so that it looks like one smooth beam, and not white with separate red thrown in.
 
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RustyKnee

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Joined
Apr 26, 2007
Messages
315
Location
England
what he said hehe

I have been taking 2xTrinitys advice in this thead about about this issue but for a bike light in this case.
https://www.candlepowerforums.com/threads/164848

I have done a quick an dirty test to show how red improves things.

note that the light sources were not precisley aligned and the red was a few cm from the white leds.

Stu
 

SemiMan

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Joined
Jan 13, 2005
Messages
3,899
Lumileds has a two phosphor warm white 1 watt. It is not very efficient 25-30 lumens at 350mA. It is 90+ CRI though. It is the best you can get from what I have seen.
 

jason9987

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Joined
Apr 27, 2006
Messages
141
Location
Dutchess Couty, NY
could they make a phosphor that works like one on a white LED ie blue LED and puts out all green instead of greenish yellow to make rgb LEDs?

or use white with a Red LED on the same die or LED(I'm not sure of the correct verbiage) to give the same effect as using a red led to compensate for the lack or red in white while not making it look like a seperate red and white light?
 
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