Manufacturers "gaming" the CRI (Color Rendering Index) system?

[tortuga]

I have been working on a few projects that require high CRI LED's (95+) and was told that lighting manufacturers now game the CRI (Color Rendering Index) system so really 95+ CRI led may not be very good at rendering color and newer TM-30 standard should be used instead of CRI.
I am curious if any of the lighting guru's on here with spectrometers have done any real world testing with both the newer ANSI/IES TM-30 method and CRI and compared it to a manufacturers published CRI as it seems manufacturers do not widely use TM-30.

 

[ron]

I am no guru, but for rendering color, I would also consider the temperature, as the higher temps such as 5000K or 6500K is better than "warmer" colors (like 3500K)

 

[Flicker Index]

I have been working on a few projects that require high CRI LED's (95+) and was told that lighting manufacturers now game the CRI (Color Rendering Index) system so really 95+ CRI led may not be very good at rendering color and newer TM-30 standard should be used instead of CRI.
I am curious if any of the lighting guru's on here with spectrometers have done any real world testing with both the newer ANSI/IES TM-30 method and CRI and compared it to a manufacturers published CRI as it seems manufacturers do not widely use TM-30.

Define "good".

If we're talking about printing, body shop and photography, the name of the game is repeatability and consistency.
If you drive your car into one shop, and hop out and look; then go to another shop, hop out and look, the colors should look the same.

It takes some time to switch gears and some Dodge Vipers were configured such that it hits 60 mph on first gear before hitting the limiter.. so it looks good on 0-60 time, however meaningless that maybe to real world driving.

Tube amps have more distortion than solid state which some consider more pleasing, but nonetheless, more distortion.

 

[tortuga]

Define "good".

Good is light from a PAR 20 50W on a incandescent dimmer.
The dimmer changes the color temperature as well as the level when the lights dim. At low they glow steady and warmer probably 2200k -1800 kelvin.
Meat, produce and fish look their correct color.
Also glare, no visible light source from where a person sits or works.
Smooth lighting, not jittery shadows from multiple little light points.
No flicker.

Here is bad:
In commercial its food especially fresh produce coolers, but also a fish & meat department colors look bad, also the LED light source is 'spotty' not uniform. One store says they saw a decline in sales from their meat counter after a new LED cooler light made all the meat look green. (I found a fix for this)
A hair and nail salon went back to halogen MR16's or at least a few halogens to get colors to look right.

In residential its kitchen lighting especially LED under cabinet lights and task lighting again especially food often does not look right especially red tones. Led's make shadows or slight flicker some say LED's gives them headaches.

 

[rambojoe]

Define "good".



Tube amps have more distortion than solid state which some consider more pleasing, but nonetheless, more distortion.

Uuhh... thats just not true... but what does overpowered cars and amplifiers have to do with light?
Dont get me wrong- im all for free thinkers, im just curious...
Or are you being facetious? Maybe im severly dehydrated today..

 

[Flicker Index]

Uuhh... thats just not true... but what does overpowered cars and amplifiers have to do with light?
Dont get me wrong- im all for free thinkers, im just curious...
Or are you being facetious? Maybe im severly dehydrated today..

That they're designed to look good on certain metrics popularity sought after or required in specs.

Having the gear ratio such that shifting occurs at 55mph or 65 mph may or may not be "better" than having it at 60, but if you start the clock at dead stop and stop the clock when it reaches exactly 60, either variants will look worse on that test.

CRI, or Ra8 is just like that. To have the output tweaked such that the average of the eight designated standardized pastel colors is as high as possible. You can have 90+ CRI and still have absolutely terrible R9 (deep red, like tomato), and sometimes even near zero.

800 series fluorescent lamps with couldn't meet the efficacy requirements, but there was a legal exception to lamps with a Ra8 CRI rating of >90. So in those last few years, lamps with lower lumens per watt and 90 CRI were produced with higher lumen depreciation and lower overall LPW, because that passed the loophole.

 

[Flicker Index]

Good is light from a PAR 20 50W on a incandescent dimmer.
The dimmer changes the color temperature as well as the level when the lights dim. At low they glow steady and warmer probably 2200k -1800 kelvin.
Meat, produce and fish look their correct color.
Also glare, no visible light source from where a person sits or works.
Smooth lighting, not jittery shadows from multiple little light points.
No flicker.

Here is bad:
In commercial its food especially fresh produce coolers, but also a fish & meat department colors look bad, also the LED light source is 'spotty' not uniform. One store says they saw a decline in sales from their meat counter after a new LED cooler light made all the meat look green. (I found a fix for this)
A hair and nail salon went back to halogen MR16's or at least a few halogens to get colors to look right.

In residential its kitchen lighting especially LED under cabinet lights and task lighting again especially food often does not look right especially red tones. Led's make shadows or slight flicker some say LED's gives them headaches.

Just about everything in your comment is outside the language of CRI and they're "irrelevant" in terms of specifications you mentioned.

 

[tortuga]

Just about everything in your comment is outside the language of CRI and they're "irrelevant" in terms of specifications you mentioned.

My bad, I thought you asked for a definition of a "good lighting" I am not sure what 'language' you speak of but I am sure my discerning customers don't speak it either they just want "good lighting". Ever since California started requiring a minimum Color Rendering Index (CRI) of 90 all of a sudden everything here now says "90 CRI" on the package and I am curious if manufacturers improved anything or just figured out how make a LED that renders 14 pastel colors correctly but nothing else, or if anyone even checks that the CRI is what the package says. It seems these "lighting facts" labels are a self certification like CE.

 

[rambojoe]

I think its a bong load thing...

 

[Flicker Index]

My bad, I thought you asked for a definition of a "good lighting" I am not sure what 'language' you speak of but I am sure my discerning customers don't speak it either they just want "good lighting". Ever since California started requiring a minimum Color Rendering Index (CRI) of 90 all of a sudden everything here now says "90 CRI" on the package and I am curious if manufacturers improved anything or just figured out how make a LED that renders 14 pastel colors correctly but nothing else, or if anyone even checks that the CRI is what the package says. It seems these "lighting facts" labels are a self certification like CE.

My understanding of your situation was that you have a project which has a line item "shall have a CRI of 95 or greater".

If you're just required to come up with something that meets specifications, it's not your responsibility to satisfy the flaws in the specifications that someone else wrote, or the legal requirements.

If something says locate two related facilities. "Two facilities shall be no more than 3/4 miles apart" and doesn't specify otherwise and there's no convention in how such is dealt, the below meets the requirements even if it realistically is 40 miles apart, but that is the specifier's fault.