Designed for both astronomical and terrestrial use, Pentax's 10x50 SP S-Series WP Binoculars can be used with confidence in all weather and conditions. The large oversized 50mm objectives are fully multicoated to reduce reflection and maximize light transmission through the entire optical path. Utilizing the traditional porro prism configuration gives scenes a rich depth of view for an immersive observation experience and provides a comfortable feel in the hand with a lot of surface area to maintain a sure grip. The large objectives and coatings maximize the amount of light getting to the user's eyes for exceptional low-light capabilities, and their high 10x magnification provides an immersive observation experience.

Complementing the optical performance are construction details made for the trail. The optical tubes are nitrogen-filled and O-ring sealed for fogproof performance and to make them submersible to as much as 3.3'. The binoculars sport a generous 20mm eye relief and the fold-down eyecups seal against the ocular cavity to block stray peripheral light which can dim images and effect night adjusted vision.