Kowa - 10x42 BD II XD Wide-Angle Binoculars

A Guide to Marine Binoculars

With a magnification-objective lens configuration favored by outdoor enthusiasts and outfitted with an ultrawide field of view, the Kowa 10x42 BD II XD Wide-Angle Binoculars produce bright high-contrast images with true-to-life color and crisp clarity even when observing from long distances.

To deliver their performance, Kowa binoculars employ complementary technologies, including the use of proprietary PROMINAR extra-low-dispersion fluorite glass, anti-reflection fully multi-coated optics, and highly reflective C3 and phase-correcting prism coatings that work together to produce crisp, clear, and bright high-contrast images with accurate color rendition across the entire spectrum. Added to this performance is a short close-focus distance, an ultra-wide angle of view, and a comfortable eye relief, which produce an immersive observational experience for any user. The expansive field of view also reduces the need to move the head very much for a more comfortable viewing experience while virtually eliminating the distracting hand shake common with high-power optics.

Designed for extensive outdoor use, the lightweight magnesium alloy chassis is wrapped in a protective rubber armor with a slip-resistant textured grip to provide secure handling in cold and wet conditions. To ensure a compact and highly packable form factor, Kowa utilizes Schmidt-Pechan prisms that allow for slimmer optical tubes but deliver the performance of conventional roof prisms. The optical tubes are nitrogen filled and O-ring sealed to be waterproof and resistant to internal fogging when moving through extreme temperature or humidity changes.

Todd Vorenkamp

5 years ago

Joseph Albanese

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11 months ago

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4 years ago

Optical Performance

High 10x magnification enables detailed observations of distant subjects like animals, athletes, and architectural details

42mm objective lenses deliver the light-gathering capability required for extended use during the pre-dawn and late dusk hours

Schmidt-Pechan prism design corrects the view while allowing for thinner optical tubes versus the more common Abbe-Koenig design

PROMINAR XD extra-low dispersion glass reduces chromatic aberration, which causes halos and fringing, for improved color rendition and contrast

Proprietary PROMINAR lens glass is made of chemically stable artificial fluorite crystal that is free of impurities, so it will not fluoresce in UV light or have a tint that can impede accurate color fidelity

Anti-reflection fully multi-coated optics improve light transmission, color rendition, clarity, and contrast

Phase-correcting prism coatings eliminate internal light diffraction to improve clarity and contrast

C3 prism coatings improve internal light transmission to higher than 99% across the entire visible spectrum to improve color rendition, clarity, and contrast

Short close focus distance of just under 6 feet enables users to make detailed observations of small subjects like bugs and insects or flora and fauna

Ultra-wide 72° apparent angle of view helps to minimize the appearance of the distracting hand shake often associated with high-power optics while offering an immersive observational experience

Spacious 378' field of view at 1000 yards

Use and Handling

Closed-bridge configuration provides a solid and stable platform for the internal focusing mechanism

Textured center focusing wheel is easy to manipulate, even in cold and wet conditions or when wearing gloves

Right-eye dioptric correction allows the user to fine-tune the focusing to their individual eyesight—even if they wear corrective lenses

Integrated 1/4"-20 threaded adapter socket on front of bridge hinge allows the optic to be tripod mounted with an optional adapter

Twist-up multi-position rubber eyecups for comfortable use and correct eye relief, with or without eyewear

Comfortable 16.5mm eye relief reduces eyestrain and improves overall viewing comfort

4.2mm exit pupil will cover most pupils as they open and dilate in low light

Construction Details

Prism design allows for thinner optical tubes, contributing to the overall compact form factor and providing a more comfortable feel in the hand

Lightweight and durable magnesium alloy chassis reduces weight without sacrificing strength and stability

Nitrogen filled and O-ring sealed to be waterproof and resistant to internal fogging when moving through extreme temperature changes or environmental conditions

Protective rubber armor provides a slip-resistant grip

Oil-resistant KR exterior lens coatings make it easy for dirt, sap, and oil to be cleaned off without smudges or residue

Light 22.5-ounce weight