Dark Sky Lighting Basics
- SHIELDING OF FIXTURES Downward pointing, fully shielded lighting keeps unwanted light from escaping into surrounding areas and the sky above. They direct the light onto the desired areas and limit glare. Outdoor lighting should be “fully shielded,” meaning no light emitted above a 90 degree angle. The more directed towards the intended subject, the better. Fully shielded lighting can be purchased or retrofitted.
- AMOUNT OF LIGHT Outdoor lighting can easily become excessive. Limiting the total amount of installed lighting can help reduce light pollution. Designing for the appropriate amount of lighting includes shining lights down instead of up, directing light only onto desired areas, and using the lowest adequate bulb intensity. Timers, motion sensors, dimmer switches, and turning lights off when not in use can all contribute to darker skies, and in many cases, reduce municipal and property owner electrical costs.
- LIGHTING COLOR The color of the light is important as well. Blue-rich lighting brightens the night sky more than warm colored lighting and researchers are beginning to connect blue-light emission to negative health effects in people and greater problems for wildlife. The IDA recommends using warm, amber-colored lighting with a color temperature of 3000 Kelvin or less. Look at product packaging to determine color temperature.
- ESSENTIAL TAKEAWAYS
- LIGHT ONLY WHAT YOU NEED: Use fully shielded fixtures. Shine lights down, not up. Direct lighting at desired areas. Be strategic with lighting and only use it where needed.
- LIGHT ONLY WHEN YOU NEED: Install timers, motion sensors, and dimmer switches, and turn off lights when not in use.
- LIGHT ONLY HOW MUCH YOU NEED: Use the right amount of light. Save electricity by using the lowest adequate wattage bulbs. Too much light is wasteful, impairs vision, and can be costly.
- LIGHT ONLY HOW YOU NEED: Use long-wavelength lights with a red or yellow tint to minimize negative health effects. Use warmer colored bulbs, like yellow or amber instead of white. Avoid bluish light, which is known to have a variety of negative effects.