> 5 seconds of research into CRI says that the first sentence is false. CRI compares a light source to an ideal black body, not necessarily daylight.
I'll clarify this a bit further: At color temperatures below 5000K (warm/neutral whites), it's compared against an ideal black body. For 5000K and up (cool whites) it's compared against CIE Standard Illuminant D[1], representing a daylight spectrum.
Two interesting notes on CRI:
1) This makes CRI discontinuous at 5000K. Two bulbs with very similar color spectrums at 4995K and 5005K can have significantly different CRI scores.
2) CRI of 100 doesn't mean it's "perfect", it means it's the same as a black body emitter (or illuminant D for cool whites). There's some recent research suggesting that people prefer oversaturated reds relative to the black body emitter, but if you put more red in the spectrum it actually lowers your CRI.
As far as the two quotes you pulled from the article
> Traditional incandescent bulbs have a ‘colour rendering index’ rating of 100, because they match the hue of objects seen in natural daylight.
Yep, totally wrong. A tungsten filament bulb is effectively a black body radiator. Being well below 5000K color temperature, it's gauged against the black body spectrum. It's the same spectrum as the reference! Of course it scores well!
> Previously researchers have warned that the blue light emitted by modern bulbs could be stopping people from getting to sleep at night
This one's a more reasonable statement. Daylight doesn't keep you up at night because there's no daylight at night. The fact that you're running a blue pumped phosphor LED at 11 PM is the potential issue. They have a giant spike of blue in the emission spectrum[2]. Exactly how that affects melatonin levels or your circadian clock is out of my expertise, but it's definitely a real concern that we need to investigate and get a better handle on.
I'll clarify this a bit further: At color temperatures below 5000K (warm/neutral whites), it's compared against an ideal black body. For 5000K and up (cool whites) it's compared against CIE Standard Illuminant D[1], representing a daylight spectrum.
Two interesting notes on CRI:
1) This makes CRI discontinuous at 5000K. Two bulbs with very similar color spectrums at 4995K and 5005K can have significantly different CRI scores.
2) CRI of 100 doesn't mean it's "perfect", it means it's the same as a black body emitter (or illuminant D for cool whites). There's some recent research suggesting that people prefer oversaturated reds relative to the black body emitter, but if you put more red in the spectrum it actually lowers your CRI.
As far as the two quotes you pulled from the article
> Traditional incandescent bulbs have a ‘colour rendering index’ rating of 100, because they match the hue of objects seen in natural daylight.
Yep, totally wrong. A tungsten filament bulb is effectively a black body radiator. Being well below 5000K color temperature, it's gauged against the black body spectrum. It's the same spectrum as the reference! Of course it scores well!
> Previously researchers have warned that the blue light emitted by modern bulbs could be stopping people from getting to sleep at night
This one's a more reasonable statement. Daylight doesn't keep you up at night because there's no daylight at night. The fact that you're running a blue pumped phosphor LED at 11 PM is the potential issue. They have a giant spike of blue in the emission spectrum[2]. Exactly how that affects melatonin levels or your circadian clock is out of my expertise, but it's definitely a real concern that we need to investigate and get a better handle on.
[1] https://en.wikipedia.org/wiki/Standard_illuminant#Illuminant...
[2] http://technologyfront.com/journalism/all-pics/true-colors-1...