Prevent LP: Basic Control of Light is Easy

Intentional Lighting Design requires a designer to move away from the site and view the design from outside the lit area. Designers should be aware of how their lighting design affects the surrounding area. Sadly, this is not often the case. The view is taken from the inside of the lighting design and looks at what is intentionally lit. Unfortunately, this is not the whole picture and designers miss the effects on what they did not intend to light.

If you want to shine light miles out to sea, use a lighthouse. If that is not the design intention then go outside the box and consider what your lights are doing. The view from the inside and the lighting levels will be with accommodated and probably fatigued eyes. Just like audio engineering and wine tasting, sometimes one needs to rest the senses and cleanse the palate. Take a look at the site from the hopefully darker surroundings. If you’ve muddled the whole surrounding area with your light, you’re not done with the design.

Light Pollution is the symptom of muddled lighting design. It wastes energy, harms people and harms the environment. Proper control of light is easy and necessary. Poor engineering has no excuse.

From International Dark Sky Outdoor Lighting Basics:

1.  Turn lights on only when needed (timers and presence detectors)
2.  Only light the area that needs it (properly direct the lights)
3.  No brighter than necessary (adaptive lighting controls like dimmers and resist the temptation to over-light)
4.  Minimize blue light emissions (3000K or less)
5.  Use fully shielded fixtures to direct and control the lighting envelope

Additional concerns or ideas:

Understand how other creature’s vision is different than human vision and consider the effect of your lighting design on them. We don’t live here on Earth alone.

In addition to properly using the normal light measurement devices, consider using an SQM to measure the contribution to skyglow your design is producing. If skyglow is increased by your lighting then your choice of shielding is not working or your light is too bright and is reflected upwards.

Confirm that you cannot see the source of your lights from the side, outside the boundaries of your site. If you can, your shielding has missed the requirements. A photon at 60-90 degrees will keep going until it hits something. It could be those houses two miles away, and their porches that people enjoy at night (or used to).