LED bulb research
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@martin I came across Waveform LED Bulbs which are apparently flicker-free. It is 800 lumens which is pretty bright (I prefer 400 lumens).
ryans Hi, I havent tried those. But I found one that works for me flawlessly, made by a czech designer. I met with him and he lent me 3 to test out. Its flicker free, with high color reproduction, and well made. Bit expensive, but he offers rental as well. Its also not fit for ceiling lighting, mostly for lamps.
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CFL and LED lighting are my major trigger in life, more so that screens. I have reams of information I have written on them.
Low power consumption, complemented by a huge service life, colossal light output and environmental friendliness – these are four indisputable advantages, thanks to which LED-based lamps are becoming leaders today.
I have also done extensive investigation into the legislation (at least in the US) around the incandescent lighting ban and the move to LED's. I can tell you, without a doubt, the reason the lighting industry pushed was this change was 100% profit driven. The margins on LED light bulbs are orders of magnitude higher than they were for incandescent and the lighting manufacturers received hundred of millions of dollars in government subsidies under the Obama administration to make the change over.
Also, while they do use less power, LED service life is on average not much longer than incandescents due to the cheap electronic drivers they use in LEDS bulbs. The lighting quality is also FAR inferior (any stimulated emission light source is going to be far inferior to black body radiation) and they have a much higher environmental impact due to manufacturing the electronic components. People here just dont care because they are manufactured in China, not here, so the Chinese deal with the pollution from thier manufacture
And in cold climates, the heat loss from switching to LED bulbs has to be made up from home heating sources, many of which use oil and natural gas, increase the carbon footprint. In short LED's are far from the miracle devices they are advertised to be. They were dressed up, oversold, and overpromised in order to fatten the profits of the lighting manufacturers.
The latest move that has been going on is a push to get legislation passed at the local level to force municipalities to switch to LED street lighting, under the guise of "green legislation", where the actual reason is to lock local governments into maintenance plans and bulb costs far higher than before. A standard high pressure sodium lamp post bulb runs around $2 and is plug an play, anyone can swap them out. An equivalent LED street lamp bulb costs over $100 and many lighting manufacturers insist you need to pay one of their servicemen to swap the bulb, or they will refuse to honor any future warranty request.
Yes, LED's have some advantages, but trust me, they are not being pushed because they help you. If LED's could compete and win in the marketplace, they wouldn't have had to have federal legislation passed mandating them.
I am very sensitive to such lightings because it gave me the same eye hurting issue when looking to the monitor before i solved my problem with monitors. All white lighting in my room and work are problem. Luckily i replace the room one with warm one and didn't install any on top of my sitting on computer. The miracle is that the new workspace has a bright white lighting just on top of my disk but zero issue. I will try to know what type of light is that.
Interestingly this video shows how incandescents possess rather significant flicker. So I'm beginning to think that it's something more to do with the light spectrum.
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martin Sorry for the slight off topic, Martin, but can that device be used to measure flicker on screens, too? As in tens or houndreds of KHz, or other smaller flicker like inversion? If so, it could be a cheaper alternative for me than a portable oscilloscope.
chahahc I think it probably depends on the person if the difference in light spectrum necessarily causes eye strain, because in my case when my issues reemerged in full swing three years ago, I tested dozens of various light bulbs (LED, fluorescent and incandescent) and even though I noticed differences in how much my eyes were strained, all of them including the incandescent ones strained my eyes anyway. The only light bulbs that I bought which don't strain my eyes are the flicker-free Waveform light bulbs which are LED. However, I do think that regular exposure to flickering LED light can cause someone to be sensitive to any type of flickering light, no matter if it's fluorescent or incandescent, because for decades I experienced little to no issues before the world changed to LED light sources.
Also, it's not always the light source, but it can be the reflection that ends up hitting your eye. In a room with the right wall color and reflectivity of floor even an incandescent light can trigger me. Thats how I learned the light source is not the issue (nor is flicker)
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degen I can only speak from personal experience. Reflection/intensity of the light is a big variable (or has been for me)
Examples:
In my back basement, I installed some overhead florescent lighting. 0 issues, I am down there for hours and hours at a time. We have the basement waterproofed, and they added a reflective white plastic material on the walls. The room now instantly gave me a migraine. I cut the plastic down, and the problem vanished. No change to the lighting, the light bulbs, or anything in the environment, just the amount of reflected light that hit my eye
In my front basement I have LED bulbs that cause me no issues whatsoever. I installed the same bulbs in the lights in the gaming area of my front basement, where the drop ceiling is 1 inch lower. That 1 inch of difference, coupled with being closer to the walls and resulting in more light reflectivity, causes me instant symptoms. Thats with the same bulb, the same fixture, the same ceiling, I even wired the whole lighting setup myself so I know even the wiring is identical.
Recently installed overhead lights in my family room, I put in incandescent bulbs which to date have never cause me an issue. Instantly triggered my migraines. The room has a very waxed floor, and the walls are painted yellow. The same exact bulbs (like, I unscrewed them and moved them myself) in a standing floor lamp in the same room? ZERO issues. Put that same bulb in an overhead lamp? Instantly unusable.
I have also inadvertently rendered computer monitors unusable by painting the room itself. I had a Sony monitor in my old office that was panted a light blue, used it all day, every day, with no issues.Painted the room green, the monitor was completely unusable and I had to sell it.
This dovetails into my theory that color of light has a major impact on our condition. Different wavelengths of light effect us, and the intensity of those wavelengths, and when a combination of a particular color and intensity of that color hits our eye, it triggers our brain to misinterpret the visual input and go haywire, resulting in symptoms.
For me at least this hypothesis holds far more water than flicker or PWM or dithering. I know a lot of people are really hooked on those theories, but they just seem a little convenient as scapegoats. I think the folks who found relief by eliminating flicker or PWM were actually getting relief by reducing light intensity and that is what is going on, but again thats just a hypothesis, I cant prove it
There is truth to this. I can unscrew an incandescent bulb that is absolutely fine in one room's overhead lamp and put it into another rooms lamp, and there are major differences in eye comfort. As far as I can tell, all of the lamp sockets seem to consist of a simple wire and no further electronics.
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chahahc I want to try the ABSOLUTE SERIES 99 CRI LED Technology | Waveform Lighting you mentioned before. It has the violet LED chip that @KM brought to our attention.
I have no experience with LED strip lighting, but it is a project I am looking into.
Their literature from that page:
Traditional white LEDs use 455 nanometer blue die as the underlying light source, and a dual-phosphor mix of green and red phosphors to achieve a semi-full spectrum light output.
This results in what is commonly referred to as the "cyan gap" - where there is a lack of light energy in the region between blue and green wavelengths, and an overshoot of blue wavelength energy. A close look at color rendering scores such as CRI R12 will also reveal that blue colors may appear over or under-saturated.
ABSOLUTE SERIES™ LEDs utilize a different method of producing white light to eliminate the cyan gap and blue overshoot. By shifting the underlying light source wavelength to a violet 420 nm die, a fuller, wider spectrum is made possible. This also provides energy coverage down to the nUV wavelength range.
The spectrum explanation is also strengthened in light of @KM finding that Quantum Dots can reduce LED backlight brightness associated pain.