Why do 70-80 CRI 6500K LEDs produce Purplish/Pinkish tint White while 95-98 CRI 6500K LEDs produce either greenish, yellowish or magenta tint White ?
LEFT : 6500K CRI80 Standard LED
RIGHT: 6500K CRI95-98 SSC Sunlike / Bridgelux THRIVE 6500K CRI 95
They don’t. It’s just a tradeoff between tint and efficacy.
This is not universally true, need to be more specific.
I just compared 70-80CRI LEDs from Cree XHP from a Sofirn 6500K flashlight, Philips 1.2M LED T5 tube and Sanan Chip 6500K flashlight. All of these have Pinkish/Purplish tint when put side by side on a 95-98 CRI 6500K Sunlike or Bridgelux Thrive LEDs
This is probably due to low CRI LEDs having a huge blue spike in the spectrum which makes things purple/blue. The SunLike/Bridgelux LEDs are meant to imitate natural light (sunlight or overcast sky) as closely as possible, and these natural sources are slightly green.
CRI and green/pink are unrelated measurements, other than that a source with very pink or very green tint cannot have very high CRI.
Updated my post above with this attachment. Here is what i am talking about. And i tested a lot of 6500K standard low CRI 70-80 LED compared to SSC Sunlike/Bridgelux Thrive. Standard Low CRI LEDs always appear either purplish or pinkish compared to Sunlike/Bridgelux Thrive High CRI.
LEFT : 6500K CRI80 Standard LED
RIGHT: 6500K CRI95-98 SSC Sunlike / Bridgelux THRIVE 6500K CRI 95
It has to do with the flourescent materials available to mix together that light. To create a hi-CRI-coolwhite light without pink tint, one had to use blue to cyan-emitting phosphor-materials ( ; 460–500nm ) as the primary component. Unfortunately those are inefficient and expensive, unlike everything else available from green to orange-red.
I am no expert in any of this, but just letting through lots of the original blue light and correcting the temperature with mostly yellow phosphorous seems like the much more easy and efficient way out.
Those Blue and Yellow-peaks in the spectrum then result in a colour-shift towards pink and and as seen by my eyes, in a dramatic increase of the disgustingness of the light.
What do you people prefer ?.
I know, most of you want light to be generally pink, but I would much rather look at the slighty green “SFT40” than at this malpractice on human dignity. ( Not even able to capture the expanse of its miscolorations accurately on camera. )
And apart from that, a green tint is also more useful in the case of a thrower which usually throws light on green vegetation.
There’s color temperature, left/right or blue/yellow on the color diagram, and tint, green/magenta or up/down on the same diagram.
Depending on the mix of phosphors plus the emitter’s color (almost always blue, but newer violet LEDs are possible), the actual color of CT+tint is like throwing a dart on a color-dartboard. Then the mfr bins them accordingly.
That’s what we call The Tint Lottery.
