Soldato
Any light at too high an intensity can damage the eyes, regardless of source. The color of the light affects circadian rhythms. Neither is news.
Another green initiative backfires?
- Thread starter mmj_uk
- Start date
As I just stated. I dont think this is about "Bright" light as such. Rather "Dim" light that has a spectral profile that we are not evolved to cope with.
Soldato
Likewise. I shudder to think how much crap my old carburettor 2.8L Granada emitted as it burned 4 star and 20W50 in near equal amounts.
The point being they are being increasingly used in street lamps and vehicle headlights which you can't avoid being exposed to in winter. It's not just directly looking at them either it can impact peripheral vision according to the Scientific Committee on Health, Environmental and Emerging Risks (SCHEER) who the EU themselves cite on their website.
The report does talk about long term exposure to low intensity LED bulbs as well hence their recommendation towards 'warm' LED bulbs in the home. How many people have a lamp plonked right next to their television or computer?
This did not really work as a funny given that up to 64,000 people die each year from air pollution in the UK.
Names and addresses, or it didn't happen!
Air quality has never been better. The way people go on about it today, it is amazing that anybody born before 1970 is still alive!
Caporegime
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They go as low as 0.5w
Apparently people don't understand more watts means more energy and because led are efficient that energy goes mainly into producing light whereas with filament it goes mainly into heat.
Just go into screwfix and buy weaker bulbs. Not hard is it?
a counter argument
you need some blue - SAD etc. and, in modern office working conditions that may have diminished from the sun,
considering relative intensity, could that be obtained with 5minutes in the sun or 30minutes under a led 4K light. ?
so, apart from the cicadean rythmn concern (blue after dusk, impeeding sleep) having some blue at home maybe beneficial, to integrate the right doseage over the day.
personal preference for 4K lights in kitchen/bathroom to make them like daylight .. (you can evaluate foodstuffs freshness too)
and, per earlier thread discussions, amber glasses for late led screen work, have never tried those glasses for night driving.
I wonder what proportion of the energy is consumed by the ballast/PSU that turns the 240Vac into the 4Vdc that the LED's need to operate? It certainly seems to be the base of the bulbs that get hot.
I am not saying the "Blue light=Bad"
Rather that low level and very blue light is something that does not occur naturally and is something that our eyes are not evolved to cope with and therefore may cause retinal damage that would not otherwise occur either in full daylight (Which is also very blue) or under traditional artificial lighting conditions (Which has always had very little blue componant, either firelight, which we have lived with for 100,000's/Millions of years, or more recent incandescent electric lighting)
Caporegime
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very little i'd imagine if they are only consuming 0.5W overall but you are right it is the base which tends to get hot.
if a bulb is blinding you in your own home you only have yourself to blame for it.
if a bulb is blinding you in your own home you only have yourself to blame for it.
lol. the funny thing is you believe that and have missed my point totally.
the real question is, Do you want to ban breathing?
Soldato
I don't disagree with what either of you posted and I stand by what I posted. LEDs are not unique in having different colour temperatures and different power outputs. There are many low-wattage equivalent fluorescents with 6k plus temperature. Metal halides too, which can go much higher. Since colour temperature is a feature of visible light we should also consider UV content in our lamps when we talk about eye damage. Some bulb types, like Mercury Tungsten Fluoros, have a moderate colour temperature but a high UV content.
Since typical, old-fashioned, incandescent household bulbs used to be warm colours with low UV content, I suppose our French cousins were just pointing it out for Jean Le Thick on the street who may not understand the science of light.
Man of Honour
Not just that, no. The spectrum of light is part of the problem - there's quite a lot of higher frequency, higher energy visible light (i.e. blue) in most LED bulbs. That can do more damage at the same level of brightness. It's also the cause of the sleep problems - the primitive parts of our brain interpret it as bright daylight (because that's the only time we'd be exposed to it naturally) and it messes with sleep/wake cycles.
I bought some "daylight" LED bulbs for my home. They reminded me of the very blue lighting my local council installed in public toilets to make it harder for addicts to use them for injecting. They might be appropriate for a lamp for some fine detail work, but not for general use. They're in my drawers of "stuff I don't use and will probably never use but are reluctant to throw away because it works" now. I have "soft white" everywhere now. I don't remember the "temperature" rating, but it's a hell of a lot less blue. I've also set my monitor to be less blue, too.
Ah, I see Orionaut wrote a better explanation of how wavelength matters in post 19.
So yes, modern LED headlights are too damn bright, but not just that.
is this anything more than higher brightness(lumens), equals more photons per second, and, the higher frequency/blue photons have more energy, or,
is there something subtler about the human bodies response ?
so, if you have twice the dose of red light is that as bad as one dose of blue.
...something to research tomorrow.
is there something subtler about the human bodies response ?
so, if you have twice the dose of red light is that as bad as one dose of blue.
...something to research tomorrow.
Literally have 4000K everywhere except bedroom lamps
4000K is a nice white-white, not a blue-white. Can't stand any cooler than about 4200K.
Really? Do you hate your house during the day? The sun is 5500k.
But I agree, warm white is best for evenings and helps you get in the mood for sleep.
Moral of OP is don’t buy crappy led lights, and don’t get daylight white. There’s plenty of other options out there colour wise.
Everyone should have. How else do you see the screen without turning on the lamp?
Or just get a dimmer switch. These things are too complex you see!
Soldato
It isn't just humans that are colour temperature sensitive. When growing chilli plants indoors I would use 6k CFLs to emulate Spring sun and promote vegetative growth and 2500k CFLs to emulate late summer sun and promote fruiting and ripening.
Soldato
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I find the coloured hue bulbs too dim 
Yes
yes .. but, if leds are more intense than the sun (some of the bike leds, with optics may well be ?) then may need special instructions.
120lumens a watt seems to be bleeding edge for efficiency, but if you know lumens, you should be able to calculate the efficiency and heat.
The better quallity led bulbs with high CRI/colour rendering , typically use rgbw leds, not phosphors, like hue, and should make foodstuffs look the correct outdoor colours,
and keep the fish(or is it the coral), or 'plants' happy ... and your eyes.