Dark Skies Lighting: a How-to
Ah, the beauty of a dark sky full of stars! In addition, there is growing scientific evidence that darkness is a biological imperative for all living organisms and the proliferation of night lighting is harming plants, birds, mammals, fish and insects.
Sensible exterior lighting techniques can reduce the amount of light that trespasses from the area it is meant to illuminate, helping to ensure a dark sky, yet maintaining the reason for the lights in the first place. Start by replacing any bulb over 60 watts with a 25 (or lower) watt bulb. A dimmer switch will achieve the same results and allows an increase in light when needed in special locations. If you are planning a major renovation or construction project, a lighting specialist can save you a lot of time and expense, and will ensure that the job is done correctly. You won't need a professional to pick out replacement light fixtures for the exterior of your home or cottage as packaging will state if it is ‘dark-sky friendly'.
Make sure that light sources point downwards and are housed in a fixture that covers the light itself. (You will note the term ‘full cut-off' or ‘partial cut-off'. Full cut-off means that no light is emitted above the horizontal. These are actually safer to use as they produce very little glare that can dazzle the eye and reduce the ability to see in darker areas. There will be enough ‘forward throw' to illuminate adequately an area beyond that just below the fixture.) A light shade can turn a standard barn light into one with no uplight yet provide wide area coverage. Floodlights should have top and side shielding and should be pointed at least 45 degrees below horizontal. Recessed pot lights built right in to the eaves or canopy of a building are naturally dark-sky friendly as they point down.
Make sure though that they are of low wattage. Replacing dusk-todawn security lights with a motion detector presents problems as wildlife can set these off. If you live on the water, aim lights away from the water and neighbouring properties. To replace boat dock lighting, there are new technologies for solar lighting, or reflector tape can be used.
