Written by Gabriel Dillard
On a clear night, you can look up and spot any number of constellations, planets and other celestial objects.
That’s not so true in the Central Valley, where light shining up from cities reflects haphazardly off trapped dust and smog particles in the air, obscuring all that hovers above.
Light pollution, as it’s been termed, is not a new problem. Since as far back as the invention of the light bulb, that familiar smoky glow has hazed over the sky above the world’s urban areas, decreasing nighttime visibility for both humans and animals.
But as more people realize its effects or simply long to see the stars, entire catalogs of products swell thicker in an effort to cut glare and prevent light from escaping into the atmosphere.
Few Valley businesses know as much about the topic as Madera manufacturer B-K Lighting.
Since its founding in 1984, the company has made it a mission to minimize light pollution, whether it be through shielding, caps, frosted lenses or fixtures that aim light beams downward instead of up in the air.
“At B-K, we want to be as minimal as possible, just to illuminate what you want lit without adding to everyone else,” said B-K Lighting’s National Sales Manager Ryan Berrios.
One look at the company’s website will give distributors a pretty good idea how to do responsible outdoor lighting, including floodlights with long, angled covers or snoots and recessed downlights that keep light from spreading out in all directions.
For custom jobs, which make up about 20 percent of B-K’s business, special adjustments can be made to hone the light output while still achieving the beautiful look homeowners or developers crave.
When lighting trees for example, Berrios said the company has produced ring mounts to place in the branches that allow light to shine downwards for a similar effect as ground-mounted fixtures.
Building and high-rise signs are among the more noticeable offenders of light trespass that B-K has managed to keep in check.
“With our linear spread lights and controlled beams, we eliminate the light trespass and we’re putting light only on the lettering,” Berrios said. He added that controlling and focusing light also helps reduce energy waste, as do new strides in LED (light-emitting diode) technology.
One standard that has helped the company meet its light limiting goals is a series of criteria set by the International Dark Sky Association (IDA).
Formed in 1988 as an astronomical venture, the organization gives its Fixture Seal of Approval to lighting products that help to reduce light pollution.
To meet the FSA criteria, luminaires must emit warm color temperatures (below 3000 kelvin), show a special certification for safety and include shielding to keep light below the horizonal plane of 90 degrees. As well, the mounting hardware must be fixed to a configuration that maintains adequate shielding. Photometric data, or light measurements, must also be submitted.
Some 70 manufacturers now have their lighting products listed on the IDA’s website, offering thousands of less blinding alternatives than older methods of illumination.
But according to IDA’s Technical Director Pete Strasser, it’s more than just obsessive glare that has municipalities like San Diego County creating ordinances to limit light pollution.
“It’s evolved to also include other aspects of night time lighting, essentially mitigating the effects of nocturnal habitat disruption,” Strasser said. “It’s also been determined there are issues with human health if light shining at night is the improper spectrum or intensity. It could get in the way of the human circadian cycle and melatonin.”
Besides the IDA’s blessing, many manufacturers also get tested for stray light, according to the BUG rating system developed in 2005 by the Illuminating Engineering Society.
The system, originally designed for street lights, analyzes the degree in which an outdoor luminaire produces backlight that radiates behind the lighting fixture, uplight shining above the horizontal plane and glare caused when light emits forward too intensely.
Sometimes, the solution isn’t redirecting the light so much as it is reducing it. Fresno Neon Sign Co. offers its customers the ability to make light on their signs brighter in the daytime and then kick down to about half output at night.
While a little more expensive, Fresno Neon sign designer Nate Mortensen said LED technology is making this more possible to do.
“With LED you can drop power and it doesn’t kill them so much,” he said. “They’re becoming more dimmable because previously the only bulbs you could dim were incandescent.”
Mortensen said it’s an option more businesses may take advantage of since an update to the City of Fresno’s signage code last year now allows for LED signage boards to be placed near one’s place of business.
The ordinance also requires illuminated lights in residential areas to be shielded in order to minimize light spillage, glare and momentary blindness.
A rheostat or other power control device should also be used to reduce glare in residential areas, according to the ordinance.
Light pollution and sky glow has been of particular interest to nearby nature preserves like Sequoia and Kings Canyon National Parks.
Each year, the Sequoia Field Institute puts on its Dark Sky Festival in the summer, treating park visitors to educational presentations by astronomers about the stars and other night sky wonders. The park’s evening campfire and Wonders of the Night Sky programs offer stargazing tours from above 7,000 feet regularly throughout the year.
But it’s more than just the tourism draw that has the parks talking about the importance of natural darkness.
Annie Esperanza, the parks’ air resources specialist and branch chief for physical sciences, said anthropogenic light in the naturally dark environment is more than just a nuisance to humans.
“In addition to wilderness, the condition of the night skies can affect wildlife interactions and other vital ecological processes, including predator/prey relationships, reproduction, navigation, and migration,” she said.
Sequoia and Kings Canyon National Parks is currently pursuing accreditation as an International Dark Sky Park, bestowed by the IDA to parks that possess an exceptional quality of starry nights and a nocturnal environment. Esperanza said the parks hope to submit the nomination package by early next year.