[HN Gopher] LED Light Spectrum Enhancement with Transparent Pigm...
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LED Light Spectrum Enhancement with Transparent Pigmented Glazes
(2016)
Author : pmlnr
Score : 11 points
Date : 2021-08-27 19:28 UTC (3 hours ago)
(HTM) web link (www.led-professional.com)
(TXT) w3m dump (www.led-professional.com)
| zan2434 wrote:
| Correct me if I'm wrong, but don't transparent pigments only
| change light color by allowing certain wavelengths of light to
| pass through them? That would mean the glaze in question here is
| only changing the color of the light by blocking out a majority
| of the light to make the distribution more uniform. These
| pigments can't actually change the wavelength of light emitted.
| That would mean this is making the LED way less efficient (in
| terms of lumens per watt), but I do applaud the low cost
| thinking!
| teslabox wrote:
| This is a nice review of one of the problems with LED lighting,
| and how the color output can be 'tuned' to provide a better
| experience.
|
| Another problem is that too much light is commonly used, and that
| blue light is both overpowering and damaging to our eyes.
|
| My local grocers have blinding spotlights in their stores. One
| grocer has okay lighting (aside from the spotlights). The other
| just replaced their fluorescent lights with LEDs that are "too
| bright" at night. I've taken to wearing my yellow-tinted blue
| light protection glasses while shopping. Just yesterday I noticed
| that the strips of LEDs in the one grocers' freezers are (now?)
| shielded, so that customers aren't blinded with strips of LEDs
| pointed into the aisles. The LED strips on the new refrigerator
| cases aren't shielded, and while they could be pointed at the
| merchandise, they're haphazardly directed. Many of the strips
| waste a lot of light by being pointed at the customers.
|
| I was at the hardware store the other day and overheard staff
| asking another customer if they wanted a warm or cool bulb. The
| customer didn't know what that meant. I interjected: "cool is the
| kind that blinds you with blue light". She wanted the warmest
| bulbs they had.
|
| At home I make an effort to use low-blue lighting, with a variety
| of amber, red, and orange LEDs, some halogen bulbs on dimmers,
| and a few 2700K LED/CFL bulbs. I found some 2200K amber LED bulbs
| for my brother's remodeled kitchen. These made his hipster
| hanging lamps useful, rather than blinding. The lights look nice
| when they're off, but they didn't realize when they were
| installed that light bulbs hanging at exactly eye level are
| terrible.
|
| I found some Citizen CLU048-1212C4 COB LEDs on clearance at
| RapidLED.com a few years ago - they are "Amber" / 2200K. The
| spectrum is similar to that provided by a High Pressure Sodium
| bulb, with a little hump in the blue portion of the spectrum (HPS
| bulbs are almost blue-free). I put a couple of these on retired
| CPU heat sinks and put them on top of the cabinets with a
| dimmable power supply/driver. This lighting is terrible for
| photography, but great for getting around the kitchen in the
| evening before bed. All the light in the room reflects off the
| ceiling. Even amber light is overpowering when you're directly
| exposed to the light source.
|
| My usual bedroom lighting is a collection of orange and red LED
| bulbs. These replaced a terrible 5000K 48" fluorescent bulb --
| even though this was completely hidden on a shelf above the
| closet, the blue light from this bulb was overpowering. The fan
| has halogen bulbs on dimmers, for when I need more than red-
| orange light.
|
| Over the last few years I've put dimmer switches on a lot of my
| lighting circuits. There's nothing worse than walking into a dark
| bathroom, flipping the switch & getting blinded. There are two
| kinds of dimmers: ones that start off and gradually ramp up the
| light level ("Slide-to-off Dimmer"), and ones that have an on/off
| switch separate from the dimming feature. At first I had the
| second type in the bathroom, but found that I'd frequently forget
| to check the brightness level before turning the switch on. The
| slide-to-off dimmers start at the minimum amount of light
| possible and gradually increase to provide the amount of light
| you need.
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(page generated 2021-08-27 23:02 UTC)