The Sightron SIII 10x42 ED II Binoculars (model 25181) are roof-prism hunting binoculars engineered for extended-range observation. Featuring fully multi-coated, extra-low dispersion (ED) glass lenses and a 42 mm objective diameter, this optical system minimises chromatic aberration to deliver sharp contrast and edge-to-edge clarity. Designed to withstand wet and humid conditions, the chassis is O-ring sealed for 100% waterproof integrity and nitrogen-gas purged to prevent internal lens fogging during abrupt temperature changes. The exterior is protected by rubber armour and incorporates a smooth central focus wheel, multi-position twist-up eyecups, and a 1/4"-20 threaded front hinge for mounting to standard binocular tripod adapters.

Key Features

• ED Optical System: Extra-low dispersion objective glass reduces colour fringing and enhances image resolution across a 325.7 ft field of view at 1,000 yards (6.2°).
• All-Weather Protection: Fully waterproof O-ring seals and nitrogen-purged internal housing prevent moisture ingress and internal fogging in adverse field environments.
• Comfortable Viewing Geometry: Generates 16 mm of eye relief alongside twist-up eyecups to accommodate users with or without eyeglasses.
• Close Focus Capability: Delivers sharp image resolution at distances down to 6.6 ft (2.0 m).
• Tripod Adaptability: Features an integrated front hinge threaded for 1/4"-20 tripod adapters to support vibration-free, stationary viewing.

Technical Specifications

• Magnification: 10x
• Objective Lens Diameter: 42 mm
• Prism Type: Roof prism
• Optical Coating: Fully multi-coated with ED glass elements
• Field of View: 325.7 ft at 1,000 yards (108.6 m at 1,000 m / 6.2°)
• Eye Relief: 16 mm (16–18 mm range)
• Minimum Close Focus: 6.6 ft (2.0 m)
• Overall Length: 5.27 inches (134 mm)
• Weight: 25.7 oz (728.6 g)
• Tripod Mount: Standard 1/4"-20 threading

Who is the Sightron SIII 10x42 ED II Binoculars for?

• Open-country big game hunters — 10x magnification combined with a 42 mm objective lens provides the long-range resolution and light gathering needed to spot distant game across open clearings while remaining manageable in a chest harness at 25.7 oz (728.6 g).
• Long-range rifle shooters — Threaded 1/4"-20 tripod compatibility paired with a 325.7 ft at 1,000 yards field of view allows spotters to secure the roof-prism binocular for steady target identification and shot placement analysis past 500 metres without hand-tremor fatigue.
• Field birdwatchers — Optical resolution down to a 6.6 ft (2.0 m) close focus distance enables observation of both distant species across open wetlands and nearby subjects without chromatic aberration.

Less suitable for: Close-range viewing under 2 metres due to the 6.6 ft close focus limit, tight bush tracking under 50 metres where a wider 8x42 optic is preferred for faster target acquisition, or multi-day alpine treks where ultralight compact binoculars under 500 g are required to reduce pack weight.