…continuedHome Lighting for Amateur Astronomers
Of the many outdoor lighting fixtures that we encountered while working on this review, several seemed worthy of a closer look. Topping the list is the GlareBuster, since it alone is touted as an astronomy-friendly lighting fixture. Inside the box we found an instruction sheet that offers a mini-lesson on light pollution as well as information promoting the International Dark-Sky Association. The GlareBuster is an extremely effective full-cutoff fixture that accepts a variety of bulbs, from standard incandescents to energy-efficient compact fluorescents.
Another fixture that provides full-cutoff lighting is the Regent RSM100 (mercury-vapor) fixture. This unit can put a lot of light on the ground while suppressing direct lighting at all angles above the fixture. The one we tested is a dusk-to-dawn model controlled by an “electric eye.” Be alert: ours came with a 175-watt mercury-vapor bulb by mistake, a lamp that will prove too strong for virtually any homeowner application. We found that it still offered substantial illumination when fitted with its proper 100-watt lamp. One disadvantage of any fixtures using mercury- or sodium-vapor lamps is that they require several minutes after being turned on before providing usable levels of illumination — they are not suited to applications where light is needed “instantly” or for short intervals.
Heath Zenith makes a large assortment of outdoor lighting fixtures. Two that caught our eye feature halogen bulbs and dual-brightness levels controlled by a motion sensor. The Heath Zenith SL-5630 is a wall-mounted unit with a single bulb recessed under a shield that offers a decent amount of vertical cutoff. We removed a small angled reflector from inside the housing (see the accompanying photograph for details). Removing this reflector is easy, since you have to temporarily remove it in the process of installing the light. This reduced much of the stray light emitted to the fixture’s sides. In fact, were it not for ribbing molded into the transparent plastic cover, this unit would keep almost all of its light directed toward levels at or below that of the fixture.
The unit is equipped with an electric eye for dusk-to-dawn operation. A few minutes after being turned on, this unit automatically dims but will instantly return to full brightness when the motion detector is triggered. Unlike motion-sensor lights that are either on or off, this one provides accent illumination in the “quiet” mode, which is desirable in many applications such as around doorways and walkways.
Heath Zenith's SL-5597 looks more like a conventional twin-bulb floodlight. It too offers the motion-activated Dual Brite feature. Furthermore, the light will automatically turn on at dusk and off after either preset intervals of three or six hours or when dawn arrives. There is manual override of the automatic features, controlled by toggling the light switch (usually inside a house) that powers the unit. Both lamp heads on this fixture have adjustable shields that are effective at reducing the angle with a direct line of sight to the bulb.
While few of today’s lighting fixtures have been designed with astronomy in mind, the conscientious homeowner can find lighting solutions that are more than adequate and, at the same time, friendly to any neighborhood skywatchers.