reticles

Reticles, also known as crosshairs, are patterns of lines or markers in optical devices that provide a reference for aiming, measuring, and aligning. They are commonly found in rifle scopes, telescopes, finder scopes, surveying instruments, and laser sights. Reticles can take many forms, from a simple central cross to duplex patterns with bolder outer legs, mil-dot layouts for range estimation, or more complex ballistic or “Christmas tree” designs that incorporate holdover points for various distances. Some are illuminated for visibility in low light, using fiber optics or phosphorescent materials; others are etched on glass or metal and are called etched or wire reticles.

In rifle scopes, reticles can be located at the first focal plane (FFP) or the second focal plane (SFP). In FFP scopes, the reticle scales with magnification, so the subtensions (mil or MOA markings) correspond to the same angular value at any magnification. In SFP scopes, the reticle stays the same size with magnification, so subtensions are accurate only at a specific magnification and vary as magnification changes.

Reticle measurements are commonly expressed in milliradians (MIL) or minutes of arc (MOA). These units support range estimation, wind corrections, and ballistic holdovers, enabling shooters to compensate for distance, wind, and drop.

Manufacturing choices affect durability and clarity. Etched glass reticles offer fine, precise lines with minimal obstruction, while traditional wire reticles provide ruggedness in iron sights. Illumination and coatings improve visibility and contrast in challenging lighting.

Reticles play roles across hunting, sport shooting, surveying, and astronomy, providing consistent reference points for aiming, measurement, and alignment.