View Full Version : High CRI raw LED Bulbs


Barry Gribble
January 4th, 2011, 12:47 PM
Hey all,

I'm interested in making some custom light sources and I want to buy high CRI raw LED bulbs (never would have guessed that from the title, eh?).

I thought I saw a link to a vendor on here long ago, but I can't find it with a search. Does anyone know of a good place? Anyone have any experience using them?

Any advice is appreciated...

Chris Medico
January 4th, 2011, 01:35 PM
Cree is one to check out.

Here is a datasheet for one of their products:

http://www.cree.com/products/pdf/xlampxp-g.pdf

Michael Panfeld
January 4th, 2011, 01:47 PM
Barry:

stop chatting online and go get that projector from Ed. Kidding.

I have been doing some research and have some info. We can chat anytime. I too am looking at making some fixtures for myself. I plan on publishing plans for a DIY Creamsource for under $700 that can be powered AC or DC.

The bottom line though is that high CRI raw LEDs or LED boards are not available for purchase. The Gekko line reports that it has a CRI in the 90s, but they also have infinitely variable color temperatures. Both the CRI and the color temp are a function of the proprietary software.

The Osram Kreios line, just announced this Fall, is only available in MOLE LED fixtures. They claim to have a higher than 90 CRI. However, I have yet to see the photometrics and test results that confirm this. In my experience light manufacturers exaggerate the claimed photometrics, some to a very high extent.

DIY LEDs available now are, at best, in the 80s as far as CRI is concerned.

Mike

Michael Panfeld
January 4th, 2011, 01:53 PM
Cree is one to check out.

Here is a datasheet for one of their products:

http://www.cree.com/products/pdf/xlampxp-g.pdf


Yup, but the color temp on the 90 CRI is 2600 to 3200. Notice that there are no CRI's given on the "daylight" range LEDs. Notice also that the daylight range LEDs have a wide band of color temps. And the 2600 to 3200 band for the 90CRI LED is pretty significant since on that end of the spectum, the MIRED shift is larger for the same absolute change in color temp (i.e., 600K), compared to the daylight shift.

Chris Medico
January 4th, 2011, 02:28 PM
Yup, but the color temp on the 90 CRI is 2600 to 3200. Notice that there are no CRI's given on the "daylight" range LEDs. Notice also that the daylight range LEDs have a wide band of color temps. And the 2600 to 3200 band for the 90CRI LED is pretty significant since on that end of the spectum, the MIRED shift is larger for the same absolute change in color temp (i.e., 600K), compared to the daylight shift.

The OP didn't indicate a color temp or anything other than a high CRI RAW emitter. I have no idea what the actual application is or what the color temp requirements are. I do have experience with building LED light sources. I expected that datasheet to spur more questions so the application could be determined and more complete advice offered.

If you are looking for a high CRI WARM white you will need to use more than one color LED to get a decent result. Choose a higher color temp for the bulk of the emission and then balance it with a yellow/red LED to fill in the warm end of the curve.

But.. That isn't what the OP asked.

Chris Ficek
January 5th, 2011, 12:02 PM
Michael Said
"I plan on publishing plans for a DIY Creamsource for under $700 that can be powered AC or DC. "

WOW! A $700 Creamsource clone--how's that possible, a real Creamsource goes for about $7000. Do you mean a look-a-like panel ? The Creamsource has 84 hi-powered LEDS and outputs like a 2K openface. I don't think you can even buy the LED's for less that $700 never mind drivers, thermal, casing, power supply and boards. I'd be VERY interested in buying one of these fixtures should you have success with your design, do you haveany price points in mind? Any idea when it may be available?

Which LEDs are you considering? Will it have DMX? Is it a fixed colour device or tunable?

I was very interested in the Creamsource fixture and had several very enjoyable chats with its inventor Tama and think the device is really on the mark...just WAY too expemsive for the world I work in. I don't know how many of these things they are actually selling but Creamsource has now teamed up with Ablecine so sales probably will get a boost from that partnership.

There seems to be a lack of high powered LED use in fixtures for the video inductry, I wonder why no one is jumping on the hi-power LED bandwagon? There is a lot of commentary on the Coolights LEDS but they use the low-power 5mm type of LEDS as does Lightpanels-anybody know the reason?

Michael Panfeld
January 5th, 2011, 12:29 PM
Chris: I have thought about making them myself versus offering them for sale. Most likely, I will just publish the part numbers and directions and let people build it themselves. As you can expect, for $700 you will not be getting DMX or color temp tunability (or a fancy fixture), etc...

It will probably be a few weeks before its ready.

Cheers

Chris Ficek
January 5th, 2011, 01:03 PM
Very interested. Please keep me in the loop. Good luck, if i can offer any assistance please let me know.