Leica's 8x56 Geovid HD-B Rangefinder Binocular combines the image quality of a large-objective anti-reflection fully multicoated optical path with the functionality of a 2000-yard laser rangefinder and integrated ballistics computer. Using an array of built-in sensors, this powerful optic measures the ambient atmospheric conditions as well as the shooter's angle relative to the target. By compiling data from the laser rangefinder and environmental sensors, the ballistics computer will calculate several values that can help improve shot placement.Leica's Advanced Ballistic Compensation (ABC) technology combines temperature and air pressure readings with rangefinder data, zeroing distance, and user-defined ballistics curve to calculate ballistic compensation values. To maximize the accuracy of compensation values, the Geovid HD-B allows the shooter to input their rifle's zero distance and select a ballistics curve corresponding to the chambered round and caliber. The HD-B is pre-loaded with 12 ABC ballistics curves for various calibers and weights, and alternative ballistics curves can be calculated using an app on the Leica website, downloaded and stored to a user-supplied microSD card and transferred to the binocular. A 4-digit in-view LED display allows the observer to view the calculated ABC values without taking their eyes off the visual scene.The HD-B model has a nitrogen-filled fogproof magnesium housing as well as fully multicoated lenses that transmit luminous and color faithful images. Leica's phase-corrected Perger Porro prism design merges the benefits of roof and Porro designs, delivering a streamlined form factor without sacrificing depth of field or color fidelity. Exposed lens surfaces are finished with Leica's proprietary AquaDura and high-transmission High Durable (HDC) lens coatings, which repel moisture and prevent dirt from adhering to the glass while reducing reflection to increase image brightness, contrast, and color.