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RGB LEDs aren't particularly suited for general purpose lighting anyway. Good white light is fairly broadband, which is why "white light" LEDs use a phosphor to

by asteli 11y ago

RGB LEDs aren't particularly suited for general purpose lighting anyway. Good white light is fairly broadband, which is why "white light" LEDs use a phosphor to get a broad emission spectrum. RGB+W LEDs exist, but I haven't seen them used in an LED strip configuration yet, unfortunately.

saidajigumi 11y ago
> RGB LEDs aren't particularly suited for general purpose lighting anyway. This. A few years back a client I was visiting had an RGB LED setup similar to this in their conference room, where our team was temporarily "housed" during the trip. It provided monumentally annoying light no matter the settings. If you're doing lighting for a space that will be used as a club or lounge where funky effects are desired and the inability to really see are OK... go for it. But even as "mood" lighting, full RGB control provides a vast, vast range of options that are truly terrible and only a few that maybe aren't. The thing is, the good current white LED bulbs are using blue+phosphor approaches to get broadband color in the warmer end of the spectrum. This trounces RGB approaches thoroughly, and they're getting remarkably good at this. Philips even has a dimmable "white" bulb that gets warmer as it's dimmed.[1] It looks fantastic, IMO. It's that kind of light quality manipulation that I find really interesting, much moreso than the effects-oriented lighting. [1] http://www.lighting.philips.com/us_en/lightcommunity/trends/led/warmglow/ http://www.lighting.philips.com/us_en/lightcommunity/trends/...
- jacobolus 11y ago
  The “blue” part of blue + phosphor is unfortunately a huge spike, and for any bulbs bluer than about 2500K CCT, ends up being awful at night. Unfortunately there are now many such (sometimes even up to 5000K) being used as street lamps and other outdoor lighting at night, and the result is extremely unpleasant. The bluish “white” LEDs might be okay for daytime task lighting though, or for help waking up in the morning. The one in your link that goes down to 2300K sounds more reasonable, but not too many people are using those as far as I can tell.
  - PepeGomez 11y ago
    >and for any bulbs bluer than about 2500K CCT, ends up being awful at night. How so? And as I've posted previously, you probably shouldn't use anything below ~4000K anyway if you want to have healthy eyes.
    - jacobolus 11y ago
      Light in the blue part of the spectrum is very distracting in peripheral vision and causes more glare because it saturates rod and short-wavelength cone photoreceptors, and it causes the eyes to adapt to an expected higher light level, which wipes out night vision. For both drivers and pedestrians, blue-wavelength glare impedes vision into the shadows, causes distraction, and slows reaction times. If you want more reasons not to have blue-wavelength outdoor lighting at night, it also disrupts melatonin production and sleep rhythms causing all sorts of human health problems, heavily disrupts wildlife circadian rhythms (both animals and plants), and creates more light pollution, making life dreary for skygazers and amateur astronomers. The best outdoor lighting is low-pressure sodium lamps. High-pressure sodium lamps, “warm” incandescent lamps, and LEDs at a CCT of ~2000–2500K are also not too terrible, especially if well shielded and not too bright: In general outdoor lighting can safely be much dimmer than most cities make it, because human vision can adapt to extremely low light levels just fine. Bright white LEDs of ≥3500K CCT are absolutely awful outdoor nighttime lighting: unpleasant, unhealthy, environmentally destructive, and wasteful of energy. For more info, see http://www.csbg.ca/articles/APPLIED_SCOTOBIOLOGY.PDF http://www.csbg.ca/articles/APPLIED_SCOTOBIOLOGY.PDF and http://darksky.org/wp-content/uploads/bsk-pdf-manager/8_IDA-BLUE-RICH-LIGHT-WHITE-PAPER.PDF http://darksky.org/wp-content/uploads/bsk-pdf-manager/8_IDA-... (and the rest of http://darksky.org http://darksky.org)
      - PepeGomez 11y ago
        Almost none of that is true, or it's only true if the lighting is designed incorrectly. Try to try it for yourself. The recommendation of using red light to preserve night vision is mostly a myth. While at the same absolute brightness red light indeed reduces night vission less, you need a much more powerful red light source to reach the same subjective brightness, which cancels out any potential benefit. The same is true for outdoor lighting. The eye is the most sensitive to ~505 nm blue-green light, so you need much dimmer white/blue-green light sources to reach equal visibility with orange ones, which both saves energy and reduces light polution. White LEDs are only a problem where no compensation was made for their higher subjective brightness. When LED lighting is used correctly, it's quite pleasant and it looks kind of like unusually good moonlight. No you can't use dim orange/"warm white" lights, because human vision can't night adapt to them, it needs the short wavelenghts for that which are missing from these light sources. It's not true that high color temperature LEDs are wasteful, on the contrary, low color temperature LEDs are inherently less efficient. Warm white will always be less efficient than more bluish light and there is nothing that can be done about that, since it's a feature of our vision. And what I meant in my previous comment is that it's likely that the exposure to unnaturally low color temperature light is what causes nearsightedness: http://www.nature.com/news/the-myopia-boom-1.17120 http://www.nature.com/news/the-myopia-boom-1.17120 and http://iovs.arvojournals.org/article.aspx?articleid=2127682 http://iovs.arvojournals.org/article.aspx?articleid=2127682
gregmac 11y ago
I have RGB+W LED strips that light my home office. http://imgur.com/a/JgWV8 http://imgur.com/a/JgWV8 The LEDs are 5050's (not individually addressable), and it alternates between white and RGB LEDs, controlled via analog/PWM (there are +5V, R, G, B and W connections). I bought this from ebay, and it came with a remote and controller (and a crappy wifi controller that I've never gotten to stay connected and working for more than 2 minutes). The remote is kind of crappy, but it does allow independent control of white brightness, RGB hue, and RGB brightness. My office is a 10x10 room with a vaulted ceiling, and I have two boxes each with two 1m strips (4m total) mounted on top of cabinets on opposite sides of the room, shining up and mostly reflecting off the ceiling. I'm very happy with this. That said, I primarily use the white (which is a "warm white") though often mix in some subtle color (eg: 50% brightness of the white). At night I'll often have more of a 1:1 mix or even the color slightly stronger, just because. When turned up full, it's significantly brighter than the 50W halogen floor lamp I used to have in here. The key thing that makes this usable for me is the white LEDs. Just to see if the RGBW vs RGB strip was worthwhile, I did actually try turning the RGBs on full when I was building it (the controller I have doesn't let you do this) and it's just not quite the same. Even though I have the strips projecting onto the ceiling (so it's indirect, soft light), the color is just.. off. If you're considering RGB LED strips as general purpose lighting, I'd highly recommend to either go with RGBW or mount a white LED strip alongside the RGB one.

by asteli 11y ago

saidajigumi 11y ago

> RGB LEDs aren't particularly suited for general purpose lighting anyway. This. A few years back a client I was visiting had an RGB LED setup similar to this in their conference room, where our team was temporarily "housed" during the trip. It provided monumentally annoying light no matter the settings. If you're doing lighting for a space that will be used as a club or lounge where funky effects are desired and the inability to really see are OK... go for it. But even as "mood" lighting, full RGB control provides a vast, vast range of options that are truly terrible and only a few that maybe aren't. The thing is, the good current white LED bulbs are using blue+phosphor approaches to get broadband color in the warmer end of the spectrum. This trounces RGB approaches thoroughly, and they're getting remarkably good at this. Philips even has a dimmable "white" bulb that gets warmer as it's dimmed.[1] It looks fantastic, IMO. It's that kind of light quality manipulation that I find really interesting, much moreso than the effects-oriented lighting. [1] http://www.lighting.philips.com/us_en/lightcommunity/trends/led/warmglow/ http://www.lighting.philips.com/us_en/lightcommunity/trends/...

jacobolus 11y ago
The “blue” part of blue + phosphor is unfortunately a huge spike, and for any bulbs bluer than about 2500K CCT, ends up being awful at night. Unfortunately there are now many such (sometimes even up to 5000K) being used as street lamps and other outdoor lighting at night, and the result is extremely unpleasant. The bluish “white” LEDs might be okay for daytime task lighting though, or for help waking up in the morning. The one in your link that goes down to 2300K sounds more reasonable, but not too many people are using those as far as I can tell.
- PepeGomez 11y ago
  >and for any bulbs bluer than about 2500K CCT, ends up being awful at night. How so? And as I've posted previously, you probably shouldn't use anything below ~4000K anyway if you want to have healthy eyes.
  - jacobolus 11y ago
    Light in the blue part of the spectrum is very distracting in peripheral vision and causes more glare because it saturates rod and short-wavelength cone photoreceptors, and it causes the eyes to adapt to an expected higher light level, which wipes out night vision. For both drivers and pedestrians, blue-wavelength glare impedes vision into the shadows, causes distraction, and slows reaction times. If you want more reasons not to have blue-wavelength outdoor lighting at night, it also disrupts melatonin production and sleep rhythms causing all sorts of human health problems, heavily disrupts wildlife circadian rhythms (both animals and plants), and creates more light pollution, making life dreary for skygazers and amateur astronomers. The best outdoor lighting is low-pressure sodium lamps. High-pressure sodium lamps, “warm” incandescent lamps, and LEDs at a CCT of ~2000–2500K are also not too terrible, especially if well shielded and not too bright: In general outdoor lighting can safely be much dimmer than most cities make it, because human vision can adapt to extremely low light levels just fine. Bright white LEDs of ≥3500K CCT are absolutely awful outdoor nighttime lighting: unpleasant, unhealthy, environmentally destructive, and wasteful of energy. For more info, see http://www.csbg.ca/articles/APPLIED_SCOTOBIOLOGY.PDF http://www.csbg.ca/articles/APPLIED_SCOTOBIOLOGY.PDF and http://darksky.org/wp-content/uploads/bsk-pdf-manager/8_IDA-BLUE-RICH-LIGHT-WHITE-PAPER.PDF http://darksky.org/wp-content/uploads/bsk-pdf-manager/8_IDA-... (and the rest of http://darksky.org http://darksky.org)
    - PepeGomez 11y ago
      Almost none of that is true, or it's only true if the lighting is designed incorrectly. Try to try it for yourself. The recommendation of using red light to preserve night vision is mostly a myth. While at the same absolute brightness red light indeed reduces night vission less, you need a much more powerful red light source to reach the same subjective brightness, which cancels out any potential benefit. The same is true for outdoor lighting. The eye is the most sensitive to ~505 nm blue-green light, so you need much dimmer white/blue-green light sources to reach equal visibility with orange ones, which both saves energy and reduces light polution. White LEDs are only a problem where no compensation was made for their higher subjective brightness. When LED lighting is used correctly, it's quite pleasant and it looks kind of like unusually good moonlight. No you can't use dim orange/"warm white" lights, because human vision can't night adapt to them, it needs the short wavelenghts for that which are missing from these light sources. It's not true that high color temperature LEDs are wasteful, on the contrary, low color temperature LEDs are inherently less efficient. Warm white will always be less efficient than more bluish light and there is nothing that can be done about that, since it's a feature of our vision. And what I meant in my previous comment is that it's likely that the exposure to unnaturally low color temperature light is what causes nearsightedness: http://www.nature.com/news/the-myopia-boom-1.17120 http://www.nature.com/news/the-myopia-boom-1.17120 and http://iovs.arvojournals.org/article.aspx?articleid=2127682 http://iovs.arvojournals.org/article.aspx?articleid=2127682

gregmac 11y ago

I have RGB+W LED strips that light my home office. http://imgur.com/a/JgWV8 http://imgur.com/a/JgWV8 The LEDs are 5050's (not individually addressable), and it alternates between white and RGB LEDs, controlled via analog/PWM (there are +5V, R, G, B and W connections). I bought this from ebay, and it came with a remote and controller (and a crappy wifi controller that I've never gotten to stay connected and working for more than 2 minutes). The remote is kind of crappy, but it does allow independent control of white brightness, RGB hue, and RGB brightness. My office is a 10x10 room with a vaulted ceiling, and I have two boxes each with two 1m strips (4m total) mounted on top of cabinets on opposite sides of the room, shining up and mostly reflecting off the ceiling. I'm very happy with this. That said, I primarily use the white (which is a "warm white") though often mix in some subtle color (eg: 50% brightness of the white). At night I'll often have more of a 1:1 mix or even the color slightly stronger, just because. When turned up full, it's significantly brighter than the 50W halogen floor lamp I used to have in here. The key thing that makes this usable for me is the white LEDs. Just to see if the RGBW vs RGB strip was worthwhile, I did actually try turning the RGBs on full when I was building it (the controller I have doesn't let you do this) and it's just not quite the same. Even though I have the strips projecting onto the ceiling (so it's indirect, soft light), the color is just.. off. If you're considering RGB LED strips as general purpose lighting, I'd highly recommend to either go with RGBW or mount a white LED strip alongside the RGB one.