so how long is the effect supposed to last?
how strong and how blue does it have to be, to remove X minutes of sleep?
wle
The liberal use of the word “may” negates the declaration of a scientific conclusion. H2O “may” be lethal… Circumstances dictate how lethal.
It’s like a magic cancer-wand. Point it at a bad guy and bam! Dude dies of cancer, and doesn’t even get to die in his sleep. Teaches him right for lurking around an alley in the dark.
I knew there was a reason why I kept all those crappy LED maglites.
I thought using a cool white for not so long on and off during a night duty LEO shift would be ok as It wasn’t excessive.
not sure, maybe best stick to NW/ Warm
For those concerned and using firefox, opera or chrome without a built in color temp changer, this add on is very handy. It’s not automatic, but just leaving it on all the time isn’t that bad either.
The quotes from the article seem to answer a lot of the questions here. The issue is constant, bright, high-CCT street lighting being linked to changes in sleep patterns/hormones.
Maybe I’ll show you some example - from photobiological safety point of view.
The main issue here is a blue light spike at 430-440nm - it’s caused by a phosphor coating quality and phosphor’s mix.
As you can see not only CCT matters, the 4000K cannot be named “safe” or “safer” sorry SKV89 ;).
I would think it’s a combination of factors that link this all together. IMO it’s mostly to do with ones lifestyle. If you’re up late regularly chances are you could be in the presence of bright light which further interrupts the sleep cycle.
At the bottom of the first paragraph “Researchers found that night shift work links to breast cancer because it can change a person’s sleep-wake cycle. This has a lot to do with artificial light.”
AsI recall, it takes only a brief exposure — think incandescent white nightlight bulb — to suppress melatonin production. Then it takes half an hour to an hour for the body to resume produccing melatonin. It’s the melatonin that suppresses breast cancer (which is why night shift workers and people in areas newly supplied with nighttime electricity show an increase)
https://www.google.com/search?client=firefox-b-1-d&channel=tus&q=melatonin+night+shift+cancer
You can buy a spectrometer kit (several variations, varying prices) from PublicLab.
https://store.publiclab.org/collections/bulk/products/lego-spectrometer-kit?variant=8187504787563
EDIT
Here’s the spectrum from one of the claimed low-blue-light 110v bulbs
See blue light associated with prostate and breast cancer - #23 by BurningPlayd0h from DominikM for spectra
I used my kit spectrometer to check the claims of bluelight suppression. A lot of it is hype — f.lux for example changes the apparent color temperature by adding more red, rather than removing blue. The spectrometer shows plenty of blue light still being emitted from the computer screen (whether fluorescent or LED lit).
I swapped amber LEDs into half our home flashlights, for nighttime use, and for room lighting we use amber LED bulbs or “bug light” compact fluorescents for evening light during the short-day half of the year.
Doing that cured our insomnia, which had gotten bad when we replaced all our incandescents with “white” compact fluorescents some years ago.
I think CCT is actually still a huge part of what’s happening there. Even 2700K light from a blackbody source will have far less of the blue end of the spectrum compared to 4000K.
https://curiosity.com/topics/this-is-how-little-blue-light-it-takes-to-disturb-your-sleep-curiosity/
has several links including this one: https://www.lrc.rpi.edu/resources/newsroom/pdf/2010/CircadianLight_8511.pdf
Yep.
It’s what matters.
4000k is better, 3000k is even better, 2700k is even better than 3000k, and 2000-2200k has almost no blue light.
I’d love to test 1800k LEDs myself.
Could someone use Luminus 3030 Cubes in Virence’s large MCPCB?
The N219b has that large blue spike, yet it is sold as photobiologically safe:
I want to learn more about how to determine the RG0 Blue Light safety requirement.
do High CRI LEDs score better than Low CRI?
does low Color Temperature score better?
etc
“Photobiologically safe: exempted from bluelight hazard” sounds like marketing hype to me.
But apparently it’s referring to a European regulation.
The “blue light hazard”
https://www.google.com/search?client=firefox-b-1-d&channel=tus&q=“blue+light+hazard”
is damage to the eye, perhaps the claim is this emitter is not strong enough for that problem to arise.
https://www.google.com/search?client=firefox-b-1-d&channel=tus&q=Photobiologically_Safe
A few years ago I corresponded with one of the researchers in the field, who said that at a European scientific conference on the subject they were already seeing industry PR people there to deny any possible problem with the blue-white LEDs their companies were pushing as “so cheap they pay for themselves in saved electricity costs” —- too cheap to meter, basically.
LOLOLOL You’re right. When they use words like ” exempt from bluelight hazard” it sounds more like bureaucratic BS than scientific fact.
Opt Lett. 2014 Feb 1;39(3):563-6. doi: 10.1364/OL.39.000563.
Phosphor-converted LEDs with low circadian action for outdoor lighting.
This is the main reason I want most of my flashlights in 2000K or below. Blue light affects my sleep at night, so keeping my flashlights at 2000K won’t give me any melatonin suppression. All my lights in the house are halogen and i cover up all sources of LEDs with red or black tape. 2000K is a little spooky sometimes though since the color temp looks like a candle flame, so i have a bunch of 2700K flashlights on hand too… just an excuse for more flashlights.
No such thing as a “Lee minus blue” filter or nuttin’?
This light is claimed to be for medical purposes. It says, it contains very little of blue wavelength. I wonder how true is it and what the led sits inside…
(ordered one a few days ago)