Technical Glossary
Trijicon's Bindon Aiming Concept™ (BAC) Feature
Trijicon's Bindon Aiming Concept™ (BAC) feature allows the shooter to track and engage targets faster by utilizing an illuminated aiming point, instead of traditional black crosshairs. Vision naturally focuses on the unmagnified view—because with motion, the magnified view blurs—while still perceiving the illuminated aiming point. As soon as the firearm begins to become steady in the target area, the brain switches to the magnified view along with the aiming point. It takes practice, but when mastered, BAC yields amazing results.
Battery-Free Illumination
Trijicon® combines world-class optics and tritium to create illuminated reticles that glow day and night without the need for batteries. The fiber optics automatically adjust the brightness levels and contrast of the reticle to available light conditions. The tritium-phosphor lamp glows in low-light conditions.
Battery-Free Trijicon Products:
BDC (Bullet Drop Compensator)
Several Trijicon® riflescope models—such as the ACOG®—feature a reticle pattern that have bullet drop compensation, designed to compensate for the effect of gravity on the trajectory of the bullet from distances between 100 to 1800 meters (depending upon the model) without making mechanical adjustments to the sight. Each Trijicon aiming solution that features a BDC reticle is calibrated for a specific bullet round (such as the 5.56 NATO, 7.62x51 NATO or 6.8mm Remington SPC). When zeroed properly, the sight is ready for aim at a multitude of distances without having to make another adjustment.
Brightness Override
This technology, such as found on the Trijicon AccuPoint®, allows users to set the reticle brightness to their specific preference. This manual adjustment is made by rotating the fiber optic housing cover to shade the fluorescent fiber optic material. Reticle is brightest when the cover is in full “open” position.
BowSync™
BowSync™ is a technology that allows the AccuDial™ ranging adjustments to “synchronize” your bow/arrow speed combination after a few simple fine-tuning steps. This means that once the sight setting is found, your AccuDial allows you to range from 0 to 80+ yards (in 1-yard increments) with a simple turn of the knob.
Dual Illumination
This refers to optics with illuminated reticles that feature two sources of battery-free illumination: tritium and fiber optics. The fiber optics automatically adjust the brightness level and contrast of the reticle to available light conditions. The tritium-phosphor lamp glows in low-light conditions.
Dual-Illuminated Trijicon® Riflescope Products:
Fiber Optics
A fiber optic is a thin, transparent fiber that is used to transmit light. The fiber optic collects available light and concentrates the light at the end of the fiber to illuminate the reticle. This automatically balances aiming point brightness with shooting conditions, thus allowing the Bindon Aiming Concept (BAC) to function.
Trijicon® Riflescope Products with Fiber Optics Technology:
MIL-Dot
A MIL-Dot reticle refers to a standard, specific pattern of duplex crosshair reticles with four small 0.25 mil diameter dots placed along each axis. These dots are arranged to allow for range estimation. A trained user can measure the range to objects of known size, determine the size of objects at known distances, and compensate for both bullet drop and wind drifts at known ranges with a MIL-Dot reticle-equipped scope.
A MIL-Dot reticle is not to be confused with a Bullet Drop Compensating (BDC) reticle, which compensates for the effect of gravity on the bullet at given distances. However, a MIL-Dot reticle can be used to estimate an approximate hold-over, or perform an elevation adjustment of the scope, if the weapon and ammunition ballistics are also known.
A “MIL” relates to the U.S. military variation of a unit of angle known as a milliradian. The distance between the centers of any two adjacent dots on a MIL-Dot reticle scope equals 1 Mil, which is about 36" (or 1 yard) @ 1000 yards, or 3.6 inches @ 100 yards. Trijicon MIL-Dot reticle is based off the U.S. Army round mil dot version. The table below lists the distance subtended by one MIL at various ranges.
It is important to note that the MIL-Dot reticle is designed to be used at the highest magnification on Trijicon MIL-Dot second-focal-plane scopes. Therefore, the scope must be set at the maximum magnification setting (i.e., 9x for TR20-2, 10x for TR22-2) to utilize the reticle for range estimation.
Sapphire Caps
Some Trijicon® iron sights contain sapphire lens technology, which focuses the brightness obtained from either tritium or fiber optics (depending upon the product) to give the maximum illumination possible while also evenly distributing light.
Trijicon® Products with Sapphire Technology:
Target Reference System (TRS)
Allows quick and accurate reference to a target’s location and is easily communicated when referring to the target in accordance with the vertical tick marks coming from the horizontal lines to the left and right of the reticle.
Tritium
Trijicon® offered the world’s very first tritium-reticle riflescope, as well as the first tritium-illuminated iron sights for handguns. Tritium illuminates the aiming point in low-light conditions without batteries. Tritium is a radioactive isotope of hydrogen. Beta rays from the tritium hit phosphors to create the glow. Tritium has a half-life of 12.5 years, which means that in that time, the lamp will be half as bright as it was originally. Trijicon offered the world’s first tritium-powered iron sights for handguns and the first tritium-reticle riflescope.