Brand: Orion Telescopes USD

Orion GiantView™ 100mm ED BT90-deg Binocular Telescope (Astronomy Star Product) (w/case) (51878)


Brand: Orion Telescopes USD

Orion GiantView™ 100mm ED BT90-deg Binocular Telescope (Astronomy Star Product) (w/case) (51878)


  • Huge 100mm objective lenses provide incredibly bright and immersive views of starry skies and daytime scenes
  • ED lenses provide the sharpest, highest contrast image possible while minimizing false color (chromatic aberration)
  • Accepts interchangeable 1.25" eyepiece pairs for a variety of magnification options (additional eyepieces sold separately)
  • Included pair of 18mm, 65 eyepieces provide 31x views out of the box
  • Waterproof and nitrogen purged, featuring 90 eyepiece orientation (specifically geared towards comfortable astronomical viewing), and weighs in at 16.8 pounds
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$3,674.95 CAD

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Special Order
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Product Description

With huge 100mm objective lenses, the Orion GiantView BT-100 ED 90º Binocular Telescope delivers an immersive observing experience. Stargazing or viewing distant terrestrial objects with two eyes provides an amazing amount of depth while also making observations more comfortable. Views of lunar craters to wispy nebulae will take on an almost 3D feel in the GiantView BT-100 ED.

The 100mm aperture objective lenses gather 56% more light than 80mm binoculars, so you'll be able to see more objects in the sky with greater clarity. The Extra Low Dispersion lenses (ED) provide the highest quality image, minimizing false color and providing extremely detailed views. And the 90° angle provides the most comfortable viewing angle when aiming high into the night sky.

The GiantView BT-100 ED Binocular Telescope includes a pair of 18mm 65° 1.25" eyepieces which provide 31x magnification and a 2.1° field. Individual eyepiece focusers provide precise focus control, while compression rings hold the eyepieces securely in place.

One of our favorite features of the BT-100 ED is its ability to accept pairs of 1.25" eyepieces so you can control magnification depending on the object (requires two identical 1.25" eyepieces to work). For the best results, we recommend using pairs of 8mm or longer focal length 1.25" eyepieces with the BT-100 ED.

You can also use pairs of 1.25" light pollution filters to significantly improve contrast while observing deep sky objects. With filters installed, the BT-100 ED provides seriously amazing views of many deep sky delicacies.

Thanks to its sealed construction and nitrogen purging, the rugged BT-100 ED is waterproof for use in damp conditions, but it's not designed for permanent outdoor installation. Bring these big binos inside after each viewing session to keep them in tip-top condition for peak performance year after year.

The big GiantView BT-100 ED Binocular Telescope weighs in at 16.8 lbs. and requires a sturdy binocular mount for stable support. A built-in threaded 1/4"-20 socket allows secure mount or dovetail plate attachment.

Note: Standard field tripods are not recommended for use with the GiantView BT-100 ED. Includes hard foam-lined carry case.

    What's in the Box

    • Orion GiantView BT-100 ED Binocular Telescope
    • Two 18mm 65° 1.25" eyepieces
    • Two objective lens caps
    • Two eyepiece caps
    • Hard foam-lined carry case


    Best for viewing Lunar & bright deep sky
    User level Advanced
    Magnification 31x
    Optical diameter 100mm
    Field of view - angular 2.1°
    Field of view - linear 112.0 ft./1000 yd
    Apparent field of view 65.0°
    Eye relief 17.0mm
    Exit pupil 3.3mm
    Near focus 90 ft.
    Coatings Fully multi-coated
    Prism BAK-4 Porro
    Interpupillary distance range 55mm - 83mm
    Focus style Individual eyepiece focus
    Waterproof Yes
    Tripod adaptable Yes
    Diopter adjustment Yes
    Weight 16.8 lbs.
    Additional included accessories
    • 18mm eyepieces (set of two)
    • Carry handle
    • Eyepiece and objective lens caps
    Other features
    • Nitrogen purged
    • Interchangeable eyepieces
    • Waterproof
    Warranty One year

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