By Ron Spomer
TRUGLO’s fiber-optic Muzzle Brite sights can be mounted on practically any inline muzzleloader.
Ever since the invention of the rifle, a common hunter’s complaint has been “I couldn’t see my sights! I could see the animal, but when I tried to aim, I couldn’t see the front sight against its body.”
As defense against such failure, hunters have put ivory, silver, gold, white paint and even tiny mirrors on open sights to lighten them for a better sight picture. While each of these “brighteners” helps to one degree or another, none matches the visibility of today’s fiber optics and “glow-in-the-dark” sights.
What are Fiber Optics?
Advertising being what it is these days, fiber-optic sights are widely misunderstood. Do they really glow in the dark or only in low light? Do they run on battery power, solar power or nuclear energy? Are they truly fibers?
Fiber optics used in communications are bundles of thin, flexible glass “hairs” surrounded by mirror-like coatings (called cladding) and protective plastic housings known as buffer coatings. From the outside, they look like regular wire cable, but inside they are a super-efficient conduit for light.
Once light enters the glass fibers, it cannot escape. The mirrored cladding constantly reflects it. Only impurities in the glass degrade the light, and a decayed signal can be refreshed by adding light at booster stations along the way.
Glowing gun sights can be built from true fiber optics, plastic “light pipes,” vials or capsules of radioactive isotopes (tritium) or a combination of those materials. Each performs to different degrees under various conditions.
True Fiber Optics
Lorraine Hellinghausen of TRUGLO Inc. says her father, Paul LoRocco, invented the fiber-optic bow sight in 1993. A professional architect and avid bowhunter, LoRocco had no experience in the fiber-optics industry. But when he came across a sample of optical fiber and saw how effectively it glowed, he converted a sliver of it into a bow sight. By 1994, he and Lorraine were marketing a single, basic TRUGLO fiber-optic sight pin for bows. It was so effective that it and its derivatives quickly dominated the bow sight market. Within two years, TRUGLO expanded into fiber-optic sights for firearms with similar success.
Today, TRUGLO and several other companies manufacture glowing sights, but not all are true fiber optics.
“You have to understand there is a difference between ‘light pipes’ and true fiber optics,” Lorraine notes. “Light pipes are injection-molded plastic rods without cladding. True fiber-optic sights, which we make, are extruded, scintillating, proprietary fibers with cladding which intensifies light, especially ultraviolet light abundant in the sky even at dusk and dawn.
“I’m no scientist or physicist, but I understand that once even the faintest light enters a true fiber optic, the cladding prevents it from escaping, so it flows down the fiber to glow brightly at the end.”
Molded plastic “light pipes” have no cladding to prevent light escaping, but they seem to be as bright as most fiber-optic sights of equal length, says Kent Heitz of Hi Viz Shooting Systems.
Phil Howe, CEO of Hi Viz, says “Three things contribute to light intensity in our light pipes: material, pigment and design.” He claims that light pipes match the brightness of extruded fiber-optic sights under natural light and slightly outshine them in artificial light. “We can mold the ends into diamonds, triangles and virtually any shape, too.”
Personally, I can see no brightness difference between extruded fiber optics and injection-molded light pipes. Both can be purchased in various colors (usually red, green or yellow). Both seem equally durable. Phil warned that both can be attacked and melted by harsh cleaning solvents. I’ve noticed that some can be too bright, creating a fuzzy glow that obscures the target.
They also can be purchased in varying diameters, the smaller sizes being dimmer and more precise. Shorter lengths of pipe will absorb less light than longer lengths, and thus will be dimmer. Some sights are designed to accept light fibers of varying end diameters and colors so you can change to match conditions. Excessively bright pipes can be toned down by covering portions of their length with opaque tape.
Neither variety produces light of its own; all they do is gather and concentrate ambient light. The longer the fiber or pipe, including loops and bends and coils, the more light it absorbs and the brighter its end glows. Different brands claim differing intensities, but all create aiming points bright enough to easily see and align sights. They’ll glow nicely through legal shooting hours in most jurisdictions. Just as important, they’ll glow brightly even at midday in full sun, something a tritium sight can’t do.
The Nuclear Option
Tritium sights produce their own light without supplemental power. Their glow results from the nuclear decay of tritium, a radioactive isotope of hydrogen. The beta rays strike phosphors to energize and make them glow. This is the same technology used to illuminate a tritium watch. It’s not hazardous to your health. According to the folks at Trijicon Inc., you’d have to be locked in a 10-by-10-foot room with 10,000 broken tritium sight capsules to suffer any health risk. The average tritium watch puts out four times more radiation.
Tritium is placed within a tiny glass capsule, which is in turn mounted inside a gun sight, protecting it. Front sights usually get one light near the top of the post; rear sights get one on each ear. Lining up the lights lines up the post and groove. Because tritium is constantly decaying, it’s always illuminated, but not enough to be seen in daylight. This isn’t a problem because the sights can then be used as standard, daylight open sights. The darker it gets, the more easily the tritium sights can be seen. Tritium will gradually grow dimmer until, after about 12 years, it powers out and needs to be replaced. Lamps can be orange, red or green, but the green ones shine brightest and last longest.
Tritium can be combined with fiber optics to create a sight that is visible in all lighting conditions from full daylight to full dark. TRUGLO builds its TFO (Tritium Fiber Optics) sights by placing a length of fiber optic in front of a tritium capsule. In this way, the capsule is fully protected within the metal sight and behind the fiber optic, which enhances its glow.
The TriViz easily attaches to a shotgun’s ventilated rib.
Why a Glowing Sight?
It’s obvious why rifle, slug gun, turkey gun and handgun shooters would want illuminated sights, but why put them on fowling guns? After all, haven’t we been taught to ignore the barrel and concentrate on the target? Proper gun fit is supposed to line the shooter’s eye perfectly with the barrel so you hit where you look. This has been proven by hunters and championship target shooters for decades. Nevertheless, shotgunners are discovering that the added visibility of a glowing bead makes it easier to learn the relationship between the target and the barrel. Experienced shooters more easily notice an improper sight picture with a bright fiber-optic sight in their peripheral vision. Target shooters report the enhanced sight impression enables them to maintain concentration over a longer period.
I was surprised to discover how easy it was to hit waterfowl in dim light when using a glowing sight. My thought was that the bright bead would be distracting, but I found it reassuring, somehow helping me better see the relationship between my swing and my target’s speed and trajectory, just as advertised.
It’s inexpensive and easy to check this for yourself. Just buy one of the tape-on or magnetic fiber-optic sights and give it a whirl. My bet is you’ll find them as helpful as a glowing sight on your whitetail barrel a half-hour after sunset.
Fiber-optic sights will never match an illuminated reticle in a bright scope for low-light shooting, but when scopes are not legal or open sights are preferred, you can’t beat that colored glow.
Reprinted from the October 2005 issue of Buckmasters GunHunter Magazine