Many homeowners seek to get away from the impositions of nearby city life and to enjoy the abundance of nature in KPVillas. Half of that experience--indeed, half our lives--occurs from sunset to sunrise. As day segues into night, visual and audible spectacles like twilight, crickets, frogs, fireflies, and stars take center stage. That is, until the contemplative darkness is disrupted by errant and excessive light.
If a thrifty LED light were a scout citing its pledge, it would put up its LED fingers and declare, "I'm useful, targeted, no brighter than necessary, controlled, and have warm colors." Stick to those key notions and your outdoor light will achieve its purpose responsibly.
Outdoor lights have most value when they achieve a specific purpose without impinging on others. Fortunately, with outdoor lights come opportunities to serve that nighttime half of our lives by minimizing errant and excessive light. While overlit architecture or landscaping is often the source of outdoor light intruding on neighbors, in KPVillas a common oversight is unshielded bulbs and bluish replacement lights. A few simple practices, including flicking off a switch, can serve the nightscape that many homeowners seek.
Light Pollution
There are three main aspects of light pollution that impinge on humans and the entire natural order:
Glare, which can be disabling, is light from the luminaire that shines directly into your eyes. Its negative effects are amplified with the ageing eye.
Light trespass is spillover light that extends beyond the intended target and crosses boundaries or property lines.
Sky glow is a light sheen across the sky caused from light bouncing off aerosols and small particulate matter. The background light washes out the night sky.
Five Questions
Dark sky advocates and the lighting industry together have crafted Five Principles for Responsible Outdoor Lighting. Good neighbors should consider these factors in the design and use of their lighting installations. The recommended practices, published jointly by the International Dark-Sky Association and the Illuminating Engineering Society, encourage using lighting that is useful, targeted, no brighter than necessary, controlled, and warm colors. Light pollution can be lessened if users ask five questions about their lighting installation:
Is it useful? Much light is functionally unnecessary, such as for architectural wall wash or uplighting trees.
Is it targeted? Lights should be fully shielded and aimed at their object so no light goes above the horizon.
Is the light level low yet sufficient? Since LEDs are so much more efficient than incandescent lights, people then tend to install or use more LED lights while justifying the savings they still realize. This rebound effect cancels out the gains made by the improved technology.
Is it controlled? Old-school technology still has a place. Simple motion detectors and dimmer switches start the savings and pollution reduction instantly. Meanwhile, modern solid state technology permits the system-wide control of the level of brightness, the time of illumination, and the color of the light output.
Is the color toward the warmer colors? LED lights are rated by color, as indicated by the Correlated Color Temperature (CCT) in degrees Kelvin. See the Lighting Facts Label on the packaging. Blue-rich lights, such as 4000K and 5000K, put out light in the color of the spectrum that affects the human circadian system. That blue is in the same wavelength as our body's peak circadian sensitivity. Avoid the blues! Use "warm" lights rated 3000K or less.
Action A few simple practices can serve the nightscape that many homeowners seek. For example, if a porch light has multiple bulbs, unscrew some. If you are out of town, turn off your lights. Use motion detectors. Don't aim lights upward. Use your necessary outdoor lights, but when done dial it back. People often are not aware of how their outdoor lights affect others, so please talk directly to your neighbor if you have issues with their lighting practices. Consider where the lighting on the exterior of your home shines. If the lighting on your home extends onto your next door neighbors home to the side, in front or rear, you might want to consider reducing the lighting out of courtesy to those who seek peaceful dark night skies. Of course, many thanks go to the homeowners who have deliberately sought less errant and excessive lighting. May you have a visceral experience under a truly dark sky and, as Walt Whitman wrote, "Look up in perfect silence at the stars." Article adapted from MACOG Promotes Responsible Outdoor Lighting; images here.