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Vixen  |  SKU: ES14304

Vixen Astronomy Binoculars BT-81S-A


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Vixen Astronomy Binoculars BT-81S-A


Want Unparalleled Clarity? Get the Vixen BT-81S-A Binoculars That Will Help You Achieve Sharp, Clear Images Without Chromatic Aberration.


  • Optimal Aperture and Focal Length: Features an 81mm aperture and 480mm focal length, providing a wide, bright field of view for both celestial and terrestrial observation.
  • Comfortable Viewing Angle: Equipped with a 45-degree angled viewing design and permanently attached diagonals for prolonged, comfortable sky-watching sessions.
  • Superior Optical Coating: Magnesium fluoride coating minimizes chromatic aberration, enhancing color fidelity and clarity for stunningly clear images.
  • Versatile Eyepiece Compatibility: Accommodates standard 31.7 mm (1.25 inch) eyepieces, allowing you to customize your viewing experience to suit your specific needs.
  • Lightweight and Durable Construction: Weighs only 9 lb (4.1 kg) with a robust aluminum body, making it easy to carry on your next adventure while ensuring long-lasting durability.
  • Included Accessories: Comes with binoculars, a practical carry handle, a viewfinder, and dew caps to protect your optics and ensure optimal performance in various conditions.
  • Exceptional Quality of View: Experience stunning views of the Moon's terminator, gaseous nebulae, vibrant star clusters, and passing comets, all rendered in sharp, contrast-rich images.

The Vixen Astronomy Binoculars BT-81S-A is for You If…

  • You Demand Unparalleled Clarity: You want binoculars that provide sharp, clear images without chromatic aberration, ensuring the best possible viewing experience.
  • You Need Portability and Ease of Transport: You seek high-performance optical equipment that is lightweight and easy to carry on outdoor excursions.
  • You Value Versatility in Eyepiece Compatibility: You need binoculars that can accommodate a variety of eyepieces and mounts, allowing for a customizable viewing experience.
  • You Require Durability for Outdoor Conditions: You want binoculars made from high-quality, durable materials that can withstand harsh environmental factors during your adventures.
  • You Desire Prolonged Comfortable Viewing: You are looking for binoculars designed for extended use, with features like angled viewing and comfortable eyepiece sockets to reduce strain during long observation sessions.
  • You Enjoy Both Celestial and Terrestrial Observation: You seek a versatile optical instrument that performs excellently in both stargazing and nature observation.


Unlock the wonders of the universe and the beauty of nature with the Vixen Astronomy Binoculars BT-81S-A, the perfect optical companion for both celestial and terrestrial enthusiasts. Featuring an impressive 81 mm (3.2") aperture and a 480 mm focal length, these binoculars deliver a wide, bright field of view, allowing you to observe the night sky and distant landscapes with unparalleled clarity. The f/5.9 focal ratio ensures a perfect balance between light gathering and image sharpness, making every detail pop, whether you're gazing at the Moon's terminator, vibrant star clusters, or the intricate patterns of a distant mountain range.

The Vixen BT-81S-A is crafted with an air-spaced doublet achromatic objective lens, meticulously designed to minimize chromatic aberration and enhance color fidelity. This is further complemented by the superior magnesium fluoride coating, which reduces reflections and ensures that the images you see are sharp, clear, and true to life. With a resolving power of 1.43 arc seconds and a limiting magnitude of 11.3, you can explore faint celestial objects and subtle details in the night sky that are often missed by lesser optics.

Comfort and usability are at the forefront of the Vixen BT-81S-A's design. The 45-degree angled viewing and permanently attached diagonals make prolonged sky-watching sessions more comfortable, reducing neck strain and allowing for a more enjoyable experience. Despite its robust construction, this binocular weighs only 9 lb (4.1 kg), making it lightweight enough for easy transport on your outdoor adventures. The high light gathering power of 134x ensures that even in low-light conditions, your observations remain bright and clear.

Designed for versatility, these binoculars accommodate standard 31.7 mm (1.25 inch) eyepieces, giving you the freedom to customize your viewing experience. Whether you're a seasoned astronomer or a nature lover, the Vixen BT-81S-A's friction-fit eyepiece holders and dovetail bar for SX/GP mount compatibility provide the flexibility and stability you need for any observation scenario.

Imagine yourself on a clear night, the vast expanse of the universe above you, each star and planet rendered in stunning detail through the Vixen BT-81S-A. Or picture a serene afternoon, observing distant wildlife and landscapes with crystal-clear precision. The Vixen BT-81S-A not only brings the faraway closer but also enhances every observation with unmatched clarity and comfort.


Discover What You Can See with the Vixen BT-81S-A

With the Vixen Astronomy Binoculars BT-81S-A, you can explore a wide array of celestial and terrestrial objects in stunning detail. Here’s a glimpse of what you can observe:

  • Celestial Objects:
    • The Moon: Marvel at the Moon's terminator, craters, and surface details with remarkable clarity.
    • Planets: View planets like Jupiter, with its bands and moons, and Saturn, with its iconic rings.
    • Star Clusters: Observe vibrant star clusters such as the Pleiades and the Beehive Cluster.
    • Nebulae: Enjoy the gaseous beauty of nebulae like the Orion Nebula, with intricate details brought to life.
    • Galaxies: Discover distant galaxies, including the Andromeda Galaxy, as bright, clear objects in the night sky.
    • Comets: Track passing comets and their tails as they journey through our solar system.
    • Double Stars: Split and distinguish double stars, appreciating their distinct colors and separation.
  • Terrestrial Objects:
    • Landscapes: Observe distant mountains, forests, and other scenic landscapes with sharp, clear images.
    • Wildlife: Watch birds and other wildlife in their natural habitats, capturing intricate details and movements.
    • Architectural Details: Explore the fine architectural details of distant buildings and monuments.
    • Seascapes: Enjoy the view of coastal areas, ships, and marine life from a distance.


Essential Accessories Included with the Vixen BT-81S-A

When you choose the Vixen Astronomy Binoculars BT-81S-A, you get a range of essential accessories that enhance your experience and provide added convenience and protection.

  • Integrated Carry Handle:
    • Easy Transport: The built-in carry handle makes it effortless to take your binoculars on the go, providing a comfortable and secure grip for long distances.
  • Integrated Finderscope Dovetail Bracket:
    • Accurate Targeting: Allows for easy attachment of a finderscope, helping you quickly and accurately locate celestial objects. Compatible with various finderscopes for customized viewing.
  • Protective Dew Caps:
    • Optics Protection: Keeps your lenses free from moisture, dust, and environmental elements, ensuring clear and uninterrupted viewing.
    • Extended Use: Prevents dew build-up, allowing for longer observation sessions.


Recommended Accessories for the Vixen BT-81S-A

To maximize your experience with the Vixen Astronomy Binoculars BT-81S-A, consider these highly recommended accessories for added stability, precision, and flexibility:

  • Vixen HF2 Fork Mount:
    • Stability and Precision: Ensure your binoculars remain steady and secure during use, providing precise and smooth movement for accurate targeting of celestial and terrestrial objects.
    • Durable Construction: Built to last, this fork mount offers robust support for your binoculars, even during extended observation sessions.
  • Vixen SXG-HAL130 Aluminum Tripod:
    • Sturdy and Lightweight: This aluminum tripod offers a perfect balance of strength and portability, making it ideal for both terrestrial and astronomical use.
    • Adjustable Height: Easily adjust the tripod to your preferred height for comfortable viewing, whether you’re observing the night sky or distant landscapes.
    • Quick Setup: Designed for convenience, the tripod allows for quick and easy setup, so you can start your observations without delay.
  • Vixen Fork Mount Swing Bracket:
    • Enhanced Viewing Flexibility: This swing bracket allows for smooth and effortless adjustment of your binoculars, providing a wide range of motion for optimal viewing angles.
    • User-Friendly Design: Easy to attach and operate, the swing bracket enhances your observational flexibility, ensuring you can quickly and easily adjust your setup as needed.


Elevate Your Viewing Experience to New Heights

Invest in the Vixen Astronomy Binoculars BT-81S-A today, and elevate your viewing experience to new heights. This is more than just an optical instrument; it's your gateway to exploring the universe and the natural world in exquisite detail. Don't miss the chance to make your observations truly unforgettable.

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Questions & Answers

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  • What makes the Vixen BT-81S-A stand out from other binoculars?

    The Vixen BT-81S-A features an 81 mm aperture, 480 mm focal length, and a focal ratio of f/5.9, providing exceptional clarity and brightness. The air-spaced doublet achromatic objective lens with magnesium fluoride coating minimizes chromatic aberration, offering true-to-life colors and sharp images. Its lightweight design and comfortable 45-degree angled viewing make it ideal for both celestial and terrestrial observation.

  • Is the Vixen BT-81S-A suitable for prolonged viewing sessions?

    Yes, the Vixen BT-81S-A is designed for comfort during extended observation sessions. The 45-degree angled viewing and permanently attached diagonals reduce neck strain, allowing for prolonged use without discomfort.

  • Can I use different eyepieces with the Vixen BT-81S-A?

    Yes, the Vixen BT-81S-A accommodates standard 31.7 mm (1.25 inch) eyepieces, allowing you to customize your viewing experience. This versatility ensures you can use various eyepieces to suit your specific observational needs.

Vixen Astronomy Binoculars BT-81S-A | ES14304 | 4955295143047

Vixen Astronomy Binoculars BT-81S-A





81 mm | 3.2"

Focal Length

480 mm

Focal Ratio


Field of View



Objective Lens: Air-spaced doublet achromatic

Optical coating: Magnesium fluoride coating

Resolving power: 1.43 arc seconds

Limiting magnitude: 11.3

Angle of view: 45°

Barrel Size



480 x 190 x 155 mm (LWH)


9 lb | 4.1 kg
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