Count on this Brunton 50mm porro prism binocular to gather a lot of light. Fully multi-coated optics only increase the distant, bright views—especially important when observing planets and stars. The Eterna delivers classic performance with modern waterproof and fogproof protection. Brunton covers the Eterna with a limited lifetime warranty.
Optical Features
Fully Multi-coated Lenses
Increase light transmission with multiple anti-reflective coatings on all air-to-glass surfaces. FlatLight coatings.
Phase Correction
Enhances resolution and contrast through roof prisms.
BaK-4 Prisms
Optimize light transmission.
Construction Features
Porro Prisms
Generally offer a rich depth of field, wide field of view, and three-dimensional image.
Rubber Armoring
Provides a secure, non-slip grip.
Adjustable Eyecups
Roll up and down for comfortable viewing with or without eyeglasses.
Individual Focus
Adjusts each binocular barrel independently.
Design Features
Waterproof
Optics are sealed with O-rings to prevent moisture, dust, and debris from getting inside the binocular.
Fogproof
Barrels are filled with nitrogen gas to inhibit internal fogging.
