# Yuji LED chip makes light closest to natural daylight



## poiihy (Jul 20, 2015)

https://youtu.be/L3LWXznJx_0

Not my video but I thought it would interest people here because of the discussions of Yuji LEDs around here.


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## FRITZHID (Jul 20, 2015)

*Re: Yuji LED chip makes light closest to natural sunlight*

96cri is impressive! I wonder about the cooling reqs and durability during use. I'd like to see these power ramped to check the vf equality of the LEDs as well.
Now if only we could get ppl to stop buying those crap COB LEDs to try and force the market into more of these higher light quality units.
Ty for the link!


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## KeepingItLight (Jul 20, 2015)

*Re: Yuji LED chip makes light closest to natural sunlight*

Wow! :twothumbs


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## Anders Hoveland (Jul 21, 2015)

*Re: Yuji LED chip makes light closest to natural sunlight*

I believe the chip shown in the video is in their "BC series" (blue-chip). 

Yuji also makes violet-chip LEDs with even higher CRI (97-98), and which really does feel like a world of difference from ordinary LED light, but unfortunately I have skin sensitivity issues with their violet-chip technology emitters  (I also have a problem with fluorescent lighting). Which makes this BC series chip LED all the more exciting to me.

I cannot say I have actually tried Yuji's BC series, but I do have some Oslon 4000K 96 CRI emitters, which are probably very comparable in light quality to the chip in the video. The color rendering is nearly perfect, as near as I can see (and I am _very_ particular), while the light feels halfway between natural sunlight and regular LED.

I would also point out that Yuji's "daylight white" is 5600K, which is quite a bit cooler than you might be expecting. Keep in mind that "daylight" includes the blue background light from the sky, and is not the same color temperature as "sunlight".


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## SemiMan (Jul 21, 2015)

*Re: Yuji LED chip makes light closest to natural sunlight*



Anders Hoveland said:


> I cannot say I have actually tried Yuji's BC series, but I do have some Oslon 4000K 96 CRI emitters, which are probably very comparable in light quality to the chip in the video. The color rendering is nearly perfect, as near as I can see (and I am _very_ particular), while the light feels halfway between natural sunlight and regular LED.



While I am not discounting that 4000K HIGH CRI is a great looking like, your comment, "The color rendering is nearly perfect" is nothing but exaggerated hyperbole.

How do you define perfect? Color rendering is always a relative measure. There is no such thing as perfect color rendering, only exactly the same as something else.

Seeing how 4000K black body sources are almost non-existent with the except of filtered sources, what are you saying this source is perfect in comparison to?

Semiman


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## FRITZHID (Jul 21, 2015)

*Re: Yuji LED chip makes light closest to natural sunlight*



SemiMan said:


> While I am not discounting that 4000K HIGH CRI is a great looking like, your comment, "The color rendering is nearly perfect" is nothing but exaggerated hyperbole.
> 
> How do you define perfect? Color rendering is always a relative measure. There is no such thing as perfect color rendering, only exactly the same as something else.
> 
> ...



Dude! Stop nitpicking every single thread you read!!!


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## Anders Hoveland (Jul 21, 2015)

*Re: Yuji LED chip makes light closest to natural sunlight*

Thanks, FRITZHID.



SemiMan said:


> While I am not discounting that 4000K HIGH CRI is a great looking like, your comment, "The color rendering is nearly perfect" is nothing but exaggerated hyperbole.
> 
> How do you define perfect? There is no such thing as perfect color rendering, only exactly the same as something else.


I mean that the colors seem to look like they are supposed to, and things have plenty of color. Not just "okay" or "good". Even with 90CRI LED emitters, the colors seem to look fine, but on careful inspection you can find the colors hues are just a little off, and that things are still not _quite_ as colorful as they are under natural light.

While off-topic, you did bring up an important point though. I am not exactly sure what CRI is based on, because sunlight that reaches the earth's surface does not exactly have blackbody distribution of wavelengths [due to Rayleigh scattering]. I do not even know if "daylight" (direct sunlight + light from the blue sky in the background) really has an exact blackbody spectral distribution either. If CRI is based on a blackbody spectrum, then an artificial 4000K l100CRI light source is not going to have the same exact type of light as sunlight at 4000K.


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## Anders Hoveland (Jul 21, 2015)

*Re: Yuji LED chip makes light closest to natural sunlight*

One of the things about 90CRI LED light, red colors do appear bright (unlike 80CRI) but deep reds do not appear the most saturated (they have a slight coral-colored tinge).
Also cyans are not the most brightly illuminated, and in some cases may not appear the most saturated either (appearing a little more greyish than they should), but it does depend on the particular pigment. I have a striped tie with two colors- azure blue and royal blue. Under 90CRI LED illumination, there is not as much color contrast, they both almost look like a similar hue of blue, just different shades, but under natural sunlight or halogen, the color contrast is more striking and looks much better.

I bring this up just for comparison.

Also one of the other things I have noticed about going from 90CRI LED to something higher is that greens become more properly rendered. At 90CRI, greens become just a little yellow-shifted, I mean emerald greens can appear more of an 'electric green' hue. Not a huge effect, but it's not a good thing.

But more than all this, once you start getting to 95CRI and above, it starts to feel less like LED light. 
(I know that sounds a little subjective, but things just visually seem more clear and in-focus)


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## DIWdiver (Jul 21, 2015)

*Re: Yuji LED chip makes light closest to natural sunlight*



Anders Hoveland said:


> But more than all this, once you start getting to 95CRI and above, it starts to feel less like LED light.
> (I know that sounds a little subjective, but things just visually seem more clear and in-focus)



Actually, that sounds a lot subjective. But in the end, isn't that the point - to make a light that people like, that _feels_ natural? Well, at least in some applications.

On the other hand there are applications where more objective measures rule the day. I think anyone discussing this topic should understand and acknowledge that concepts like 'optimum' and 'perfect' have meanings that are (or at least can be) poorly standardized and application-specific, while terms like CRI have very specific and objective definitions, and that _any_ concept or definition may or may not be critical or even relevant to a particular application.

I could be wrong about this, but I think 'color rendition' is a concept that has no standardized definition or objective valuation. Thus it can only be appropriately used in narrowly defined applications or comparisons, and is not appropriate for use in comparisons of broad applications or disparate observers.

On the other hand, 'CRI' or 'Color Rendering Index' is a very standardized and objective measurement that can be agreed upon by many disparate observers. Its very specificity, unfortunately, limits its usefulness in certain cases. Small differences in CRI will not necessarily correlate well with subjective observance of 'quality'. However, large differences in CRI will nomally correlate with subjective observance of 'quality'.

Oops, time to eat my words. According to Wikipedia, 'CRI' is a general term, while the international standard measurement is called 'CIE Ra'. Caveat emptor. Sounds like most people mean 'CIE Ra' when they say 'CRI', but there's no guarantee of that!


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## SemiMan (Jul 22, 2015)

*Re: Yuji LED chip makes light closest to natural sunlight*



FRITZHID said:


> Dude! Stop nitpicking every single thread you read!!!



Dude I only (almost) criticize the stuff that Anders writes as he knows enough buzz words to look like an expert but is not. He often posts erroneous info ... And someone needs to point it out ... So everyone else can learn facts not fiction.


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## FRITZHID (Jul 22, 2015)

*Re: Yuji LED chip makes light closest to natural sunlight*



SemiMan said:


> Dude I only (almost) criticize the stuff that Anders writes as he knows enough buzz words to look like an expert but is not. He often posts erroneous info ... And someone needs to point it out ... So everyone else can learn facts not fiction.



No, I've been reading enough to see that you tend to OVER criticize Damn near every thread you feel needs your "expert" opinion.
We get it already, You think you know everything. 90% are tired of hearing about it! The other 10% think ....well, it's kinda like having a huge Wang... It's ok to be proud of it. You go about smacking ppl in the face with it however, then we have problem. You believe you're the end all/be all of lighting and everything is as black and white as you say it should be.... Well it's not pal, and I along with quite a few others, are tired of you cramming it down ppls throats. It's one thing to correct, it's another to be a Jack ***. Care to guess which side you're on?
Give it a rest already.


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## SemiMan (Jul 22, 2015)

*Re: Yuji LED chip makes light closest to natural sunlight*



FRITZHID said:


> No, I've been reading enough to see that you tend to OVER criticize Damn near every thread you feel needs your "expert" opinion.
> We get it already, You think you know everything. 90% are tired of hearing about it! The other 10% think ....well, it's kinda like having a huge Wang... It's ok to be proud of it. You go about smacking ppl in the face with it however, then we have problem. You believe you're the end all/be all of lighting and everything is as black and white as you say it should be.... Well it's not pal, and I along with quite a few others, are tired of you cramming it down ppls throats. It's one thing to correct, it's another to be a Jack ***. Care to guess which side you're on?
> Give it a rest already.



(1) Frankly, I don't give a rat's butt what you think about my posts.

Lighting is like teaching, everyone thinks they are an expert because they have some exposure to it. If you want to see some real "criticism" on CPF, I suggest you head over to the Automotive thread where the moderators don't take kindly to the spread of misinformation.

The level of misinformation that is posted on CPF w.r.t. lighting (electronics, LEDs, solar), especially by some posters is significant, and often people take personal experience as fact, even though there is often bodies of research on a range of population that shows otherwise. Just because people don't want to believe there is a "right" or significantly "right" answer does not mean it does not exist. The internet is a great source of bad information. CPF does not have to be.

That people feel the need to post as fact, information which either they know is not, or that which they are not sure is correct, does not mean I have to be politically correct in my responses. 

Perhaps YOU don't know Fritzhid, but some really great posters, NEWBIE comes to mind, quit coming to CPF because of attacks like yours. NEWBIE would take a lot of time to post really valuable information on LEDs, and general technical topics. Some of the best information CPF has ever seen. However, he was attacked by the likes of people like you because he would stand up to misinformation and some CPF members don't like to be told they are not wearing any clothes. So to that end, see (1) above. 

Semiman


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## FRITZHID (Jul 22, 2015)

*Re: Yuji LED chip makes light closest to natural sunlight*



SemiMan said:


> (1) Frankly, I don't give a rat's butt what you think about my posts.
> 
> Lighting is like teaching, everyone thinks they are an expert because they have some exposure to it. If you want to see some real "criticism" on CPF, I suggest you head over to the Automotive thread where the moderators don't take kindly to the spread of misinformation.
> 
> ...



No, many have left cpf cause of Nazi lighting posters like yourself. You need to step back and critique your own comments before hitting that send button. We're all tired of your rhetoric. I know for fact that most of us would welcome your posts if you weren't so Damn condescending! Take a few seconds and rephrase your comments before posting in order to sound less like a *******. 
Not to mention, let some opinions go once and a while! 

Again, things aren't as black and white as the pages you consistently spew at everyone here! 
Give it a f'n rest already!


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## FRITZHID (Jul 22, 2015)

Saddest part is, semiman, (semi-man, as in only a little bit man) 
I used to have respect for you.... Now I just see you as a jerk/bully..


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## Anders Hoveland (Jul 22, 2015)

It's amazing the type of things people can argue over. You wouldn't think flashlights and LEDs could be such a controversial topic.

reminds me of an adage I once encountered on a different message board:

"Arguing on the internet is like running in the Special Olympics. Even if you win, you're still retarded."


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## SemiMan (Jul 22, 2015)

Feelings mutual Fritzhid. Let's leave it at that. If you have issues with me, that is what PMs and moderators are for. Grow up.

To quote moderators attack the post .... Which is what I did with Anders post.


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## FRITZHID (Jul 22, 2015)

SemiMan said:


> Feelings mutual Fritzhid. Let's leave it at that. If you have issues with me, that is what PMs and moderators are for. Grow up.
> 
> To quote moderators attack the post .... Which is what I did with Anders post.



No, you've attacked every thread you've posted in..... And we're all tired of it.


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## mercrazy (Jul 22, 2015)

i'm just thankful i found a place where almost everybody knows more than i do about LEDs and electronics. lots of good information here. i do understand there are differences of opinion. on subjects i do know something about, i see a lot of false information online but i don't know how to stop it. i usually just respectfully disagree and move on.


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## SemiMan (Jul 22, 2015)

FRITZHID said:


> No, you've attacked every thread you've posted in..... And we're all tired of it.



Nice to know that you speak for everyone Fritzhid. Did you get elected GOD and I did not find out about it?

Congratulations.


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## SemiMan (Jul 22, 2015)

Speaking of picking on Anders 

Anders, I will assume you will read this, since it's a high CRI thread. Based on your posts, you are likely most capable of putting this together at this point and I am sure most CPF members would find it useful .... someone tried in the past, but it seemed to have faded.

Why not put together a high CRI table/sticky thread on CPF of Emitters, or Emitters and sources

Vendor
Product
CCT
How spectrum is achieved
- Simple phosphor converted, phosphor converted with unique phosphors, i.e. like quantum-dot red, white+red, etc.
CRI-Ra(8)
CRI-R9
CRI- R10-15 (if available)
Spectral plot if available
Efficiency
Link to data sheet
Etc.

You may be able to gleam the initial table from other sources on the web, but pretty much everything I have seen is lacking in critical details. You have mentioned enough sources that you should have a pretty good data set already.


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## FRITZHID (Jul 22, 2015)

SemiMan said:


> Again Fritzhid, grow up. If you have an issue, feel free to PM or contact a moderator. This is not the place and you are only showing yourself to be immature.



No, pm's go ignored, I'd rather have everyone see.
And as far as you go, I've watched you correct people's OPINIONS! That's like saying someone is wrong for feeling a certain way! The only thing I've tried to get across to you at this point was GIVE IT A REST ALREADY! Stop picking on Anders and everyone else. It's one thing to offer info, it's a whole other to be that one guy that feels the need to correct EVERYONE all the time.


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## SemiMan (Jul 22, 2015)

Again Fritzhid, difference of opinion ... and feel free to keep yours to yourself.

People are quite liberal with spouting opinion as "fact". W.r.t. Anders that is between me and Anders ... and yes I will call out BS.

I have asked a moderator to delete these posts as you don't seem to want to give it up.

The only PM I have ignored from you is where you asked for my personal contact info ... which I choose not to provide and told you.


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## Bullzeyebill (Jul 22, 2015)

I removed two posts, re profane language. This is a family forum. This thread is a perfect example of a thread gone bad. Bickering between two members has ruined any chance of this thread amounting to anything. I am closing it.

Bill


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## Greta (Jul 22, 2015)

SemiMan said:


> Again Fritzhid, difference of opinion ... and feel free to keep yours to yourself.
> 
> People are quite liberal with spouting opinion as "fact". W.r.t. Anders that is between me and Anders ... and yes I will call out BS.
> 
> ...



Thank you for closing this thread, Bill. I will add just one more thing though...

SemiMan... With THIS post of yours, it seems YOU don't seem to want to give it up and you even resort to foul language. You have been warned about this _same exact behavior _several times before. This is your last warning - KNOCK IT OFF! If you have such little control of yourself, then please do us all a favor and go somewhere else. 

FRITZHID - You too have been warned previously about your language and this type of sandbox behavior. So to you also, this is your last warning - KNOCK IT OFF! 

Good God - I have bulldogs who listen and behave better than you two! :shakehead


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