Cities are swapping traditional light bulbs for more energy-efficient brighter LEDs. The rise of these blue LEDs are creating problems for our night sky and our health.
Quick counter: lower kelvin lights are terrible for color reproduction. Pure sunlight is around 5000K, and has a CRI (color rendering index) of 100. Switching to warmer (lower kelvin) lights is going to also alter your CRI, and will change the way that you perceive colors. If you need high color discrimination, that’s going to be bad.
For outdoor lights, in most cases that’s not a problem.
Usually. In most cases, you aren’t going to notice just how much the colors have shifted, because your brain automatically adjusts. Youre perception of color is usually how colors appear relative to other things; you will see a red as red because your brain is comparing it to other objects with a known color. OTOH, if you’re taking photos under poor lighting conditions, you’ll see a significant shift in color. If you’ve ever taken film photos under fluorescent lights, you’d see that everything looked sharply green, when you don’t perceive them as being green at that moment. (Digital cameras often make color adjustments, and the sensors are often not as sensitive as film can be.)
Going to an extreme, if you use a red filter on a light source, all colors are going to end up looking brown and grey; switching to red lights does the best at minimizing light pollution and loss of night vision, but at the cost of most color information. That’s not bad, just a thing to consider.
Not really, CRI is not dependent on color temperature; 2400K and 2700K incandescent bulbs all have CRI of 100. And, as you said, human brain is incredibly good at adopting to light color temperature. While I would not do color-critical work in candlelight, 2700K and 2400K bulbs are perfect for general late evening lighting and 3000K…3500K is very good for task lights. Higher than 4000K lights should not be a thing in domestic or public outdoor lighting, it’s just too harsh and uncozy.
You don’t need high lumens, either. As an extreme example, I’ve done plenty hiking (and patrolling during my military training) in starlight with no artificial light source—the eye is quite remarkable at adopting to darkness. The cities today are overly bright at nights, you could easily halve (or more) the lumen output and be absolutely fine. Even light distribution with no shadowy dark spots is way more useful than overly bright lights. Another personal anecdote, I live on 9th floor and I don’t need to turn on any lights when visiting bathroom at night; the light pollution from outside through curtains is enough to navigate around in my apartment.
Quick counter: lower kelvin lights are terrible for color reproduction. Pure sunlight is around 5000K, and has a CRI (color rendering index) of 100. Switching to warmer (lower kelvin) lights is going to also alter your CRI, and will change the way that you perceive colors. If you need high color discrimination, that’s going to be bad.
For outdoor lights, in most cases that’s not a problem.
Usually. In most cases, you aren’t going to notice just how much the colors have shifted, because your brain automatically adjusts. Youre perception of color is usually how colors appear relative to other things; you will see a red as red because your brain is comparing it to other objects with a known color. OTOH, if you’re taking photos under poor lighting conditions, you’ll see a significant shift in color. If you’ve ever taken film photos under fluorescent lights, you’d see that everything looked sharply green, when you don’t perceive them as being green at that moment. (Digital cameras often make color adjustments, and the sensors are often not as sensitive as film can be.)
Going to an extreme, if you use a red filter on a light source, all colors are going to end up looking brown and grey; switching to red lights does the best at minimizing light pollution and loss of night vision, but at the cost of most color information. That’s not bad, just a thing to consider.
Not really, CRI is not dependent on color temperature; 2400K and 2700K incandescent bulbs all have CRI of 100. And, as you said, human brain is incredibly good at adopting to light color temperature. While I would not do color-critical work in candlelight, 2700K and 2400K bulbs are perfect for general late evening lighting and 3000K…3500K is very good for task lights. Higher than 4000K lights should not be a thing in domestic or public outdoor lighting, it’s just too harsh and uncozy.
You don’t need high lumens, either. As an extreme example, I’ve done plenty hiking (and patrolling during my military training) in starlight with no artificial light source—the eye is quite remarkable at adopting to darkness. The cities today are overly bright at nights, you could easily halve (or more) the lumen output and be absolutely fine. Even light distribution with no shadowy dark spots is way more useful than overly bright lights. Another personal anecdote, I live on 9th floor and I don’t need to turn on any lights when visiting bathroom at night; the light pollution from outside through curtains is enough to navigate around in my apartment.