Blue light is very, very bad.

Good luck chinooker with the treatment, that does not sound like a lot of fun, but I hope it works!

More info from American Cancer Society on treatment of actinic keratosis which are considered pre-cancerous lesions.

My arms/hands are pretty much healed of the treatment and already look much improved with fresher looking skin and way fewer bumps and barnacles. My 2nd & last facial was last week and has peeled like my worst sunburn. My 2nd & last arm treatment is scheduled on the 24th. I recommend this over the Chemotherapy or Cryosurgery which can miss quite a few of the small ones which then show up later. This covers the whole area that the liquid is applied.

They say no exposure to sunlight for a few days. I knew better and I had my hat on and I just needed to run the riding mower up to the new shed our contractor is building so he could adjust the ramp for proper clearance for the cutting deck. Wow, I paid dearly for just a few minutes off side exposure to the early morning sunlight. Pay attention to their instructions!

I find it quite amusing to see people using his smartphone screens with “night modes” activated, makes screens look like CRAP. :-D

A slight screen temperature correction can be beneficial for those willing and able to do it. Related information: http://www.tannerhelland.com/4435/convert-temperature-rgb-algorithm-code/

LMAO!

Cheers :-)

Blue light wakes you up. Without it we would aways be somewhat tired.

I hope for a little continuation within the thread of blue light. I see no reason to open new one though, so allow me to blend into this one.

I got really interested in blue light contribution since I’ve learnt it has more meaning than I first thought.
Just summing up what I’ve learnt so far:

- blue light is the factor that attracts insects. Its lack makes a light neutral for insects (and probably also some other living forms)

- blue light is unhealthy for human: lower melatonine surpression, may favor cancer, may damage eyes

  • not sure about its night vision preservance capability

So my first thought was to search for light without content of blue wavelenghts which turned out not to be so easy. So far I’m falling in love with the red light (mainly for above mentioned reasons) since I know it has many advantages. But there are also some other choices. Wiser than me say a warm light contains quite a little of blue but even 2000K contains some. And here’s the question: which white LED would have least blue? What factors decide of amount blue emmited? I think besides the color temperature a tint should have a meaning too?

I’d really like to know if good pretenders (like E21A 2000K, XP-E2 red 620/660, XP-E2 amber, XP-E2 green, XP-L 3000K, SST-20 2700K etc.) are in fact so “blueless” as one might thought.

At least I have two good reasons to search for such led: 1. Insects, 2. good health
Will you contribute your knowledge? Please.

PS: some other posts on blue light:
jon_slider
MontyPyfon
brad
1stein

Only at night!!!

It is absolutely essential during the day. Sunlight has a high blue content. It is the natural light source that humens are adapted to. It makes you more awake during the day.

If you want good lighting at home, just make it as natural as possible (=> similar to the sun). Bright cool-white light during the day and dimmer, warm light in the evening.

All “white” light will have some blue. The lower the CCT, the less blue it will contain. You’d need to check the datasheet for any particular emitter for its emission frequency range and compare to the frequencies that you consider “blue” to see how much blue spectrum light it emits.

Any monochromatic LED that isn’t blue should contain no blue spectrum light, except for maybe some “green” emitters, such as Cyan. Again, you should be able to check the datasheet to see if it has any blue spectrum light emission. Monochromatic emitters of red, orange, amber, and some greens should be completely blue-light free.

There have been conversations on here and elsewhere about blue-light free nighttime lighting. IIRC, the recommendation is to use just red, orange, and amber lights at night. This works whether you’re talking about human melatonin production or just trying not to attract bugs. But, for most of us, simply using “less” blue light seems to be enough.

This is the bottom - I use flashlights only when it’s dark, mostly when walking the dog just before going sleep. Usually 60-90 minutes.

that is not contradictory, it is about damage to the retina, which is not the topic of this thread

blue light interferes with sleep, by suppressing the hormone that supports sleep, melatonin

blue light is not bad during the day, when we need to be awake, and alert

The intensity is important, too. One of the main studies I’ve found on the effects of light of different CCT’s (where higher CCT’s have more blue present) on melatonin suppression was conducted in a room lit to 200 lux.

That’s not necessarily easy to compare to a flashlight beam where the illumination around you will be uneven, but I think it’s safe to say we’re talking about several hundred lumens of illumination up close, and significantly more further away to cause equivalent melatonin suppression to cause comparable levels of suppression.

Of course, other studies have looked at intensity specifically as a variable, and melatonin suppression continues down to much lower levels, although this study saw on 2% melatonin suppression at 22 lux for 1 hour from ~2700K light.
https://www.researchgate.net/publication/315646147_A_Working_Threshold_for_Acute_Nocturnal_Melatonin_Suppression_from_White_Light_Sources_used_in_Architectural_Applications

Who knew those KMart ‘blue light specials’ were so hazardous?

I have an observation that the modern imbalance of omega 6 to omega 3 (ideally, 1:1) (the well known, by the food chemist’s who are highered by food processing industry, hne byproduct is very bad, especially) will replace the body natural lipid balance, allowing unstable oxidation (leading to atherosclerosis), skin cancer, premature skin aging. Likewise, susceptibility to daylight that our ancestors, before 10,000 years ago would not have been affected by. It does not help that in the last 100 years, formerly industrial oils have become partially hydrogenated to allow some semblance of ediblibilty and stability.

So, take this near sighted article with a gram of fish oil to balance out your modern overdose of “heart healthy” hydrogenated omega 6 vegetable oils.

It is when it alternates with red is when you have to worry

Unless you’re in Chicago…


Anyhoo, interesting article I just came across today. You don’t even have to see blue light for it to kill you dead.

This comment deserves some type of award!

I am rather unhappy with the whole flashaholic community who taught the police how to build low profile light racks. Life was easier in the days when police drove around, roofs adorned with easy to spot, and yummy looking, bubble gumball machines. (Also, I heard they drove at night, slightly lit, by a pilot light, in my parent’s day. )

This library service gives access to a lot of scientific discussion and research papers, and helps people find relevant work.
You can download one at a time free.

Here’s the problem:

At least in Connecticut, I’ve seen troopers just cruising with a steady red light on top. There’s a name for that but I forgot what it is (and I’m still trying to find out).

I thought from vague recollection it may have been “California light”, but searches turned up nothing of interest. Must be something else…

Best I could find was “cruise lights”, but I was (mis?)remembering a location associated with the term.

If you are a mouse, warm colored light may be worse for sleep than blue light

Was under the impression cruiser lights are blue this side of the Mississippi, and red
On the left.

Like radio call signs start with “W” east of Miss, and “K”, west.

Of course, it may be a myth ….