Take your observing to the next level with the Explore Scientific BT-120, the most powerful and light-hungry instrument in the acclaimed BT binocular lineup. Featuring massive 120mm objective lenses, these binoculars collect more light than any other model in the series—making them ideal for deep-sky astronomy, planetary viewing, and long-distance terrestrial observation in any lighting condition.
Each eye is treated to its own dedicated full-aperture refractor, providing a true stereoscopic experience that enhances depth perception, reduces eye strain, and immerses you in rich, high-contrast visuals. Whether you're following Jupiter's moons, scanning the Milky Way, or tracking distant aircraft, the BT-120 delivers unparalleled image clarity and brightness.
Housed in a rugged, waterproof magnesium body, the BT-120 is built for serious field use. Argon-purged optics resist internal fogging, while extendable dew shields and 45° angled eyepieces ensure comfortable, uninterrupted observing sessions—even in damp or chilly conditions.
The included 20mm 62° LER eyepieces yield a powerful 33x magnification, and the standard 1.25" eyepiece holders allow for customization from 25x to 75x using compatible eyepieces.
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⭐ Features & Benefits
- Largest BT Model – Massive 120mm objective lenses offer superior light-gathering for deep-sky and low-light observation.
- Stereoscopic Refractor Optics – Two full-aperture refractors create an immersive 3D-like view with reduced eye fatigue.
- Includes 20mm 62° LER Eyepieces – Delivers 33x magnification with comfortable eye relief, ideal for extended viewing.
- 1.25" Eyepiece Holders – Swap in your favorite eyepieces to achieve 25x to 75x magnification ranges.
- Argon-Purged, IPX6 Waterproof – Built to withstand harsh environments, resisting fog, moisture, and debris.
- EMD Coated Optics – Enhanced Multilayer Deposition coatings ensure bright, high-contrast, color-accurate images.
- 45° Angled Eyepiece Design – Reduces neck strain during zenith viewing or long stargazing sessions.
- Dual Helical Focusers – Provide smooth, independent focus for precision tuning in each eye.
- Extendable Dew Caps – Help block stray light and prevent fogging in humid or cold air.
- Lightweight Magnesium Housing – Offers rugged protection without unnecessary weight.
- Tripod Ready – Built-in mounting thread and carry handle make transport and setup simple.
- Lifetime Collimation Support – Includes access to Explore Scientific’s lifetime collimation service (shipping not included).
🌌 Perfect For
- Deep-sky exploration and faint galaxy hunting
- Serious planetary observers seeking brightness and clarity
- Long-range daytime spotting across mountains, oceans, and terrain
- Observers who demand field-ready durability and performance
🎒 What’s Included
- Explore Scientific BT-120 Giant Binoculars
- Two Explore Scientific 20mm 62° LER Eyepieces (33x magnification)
- Integrated carrying handle
- 1.25" eyepiece holders
- Threaded tripod mount
- Instruction manual
Specs
| Item Number | 01-14230 |
|---|---|
| Optical Design | Achromatic Refractor (Porro) |
| Objective Lens Diameter | 120 mm |
| Focal Length | 660 mm |
| Focal Ratio | f/5.5 |
| Magnification (Included EPs) | 33x (with 20mm eyepieces) |
| Apparent Field of View | 62° |
| True Field of View | 1.8° |
| Exit Pupil | 3.6 mm |
| Eye Relief | 15 mm |
| Interpupillary Distance Range | 54 – 76 mm |
| Waterproof Rating | Yes / IPX6 |
| Fogproof | Nitrogen Purged |
| Coatings | Enhanced Multilayer Deposition |
| Housing Material | Magnesium |
| Eyepiece Holder Diameter | 1.25 inch / 31.7 mm |
| Tripod Threading | 2 × 1/4", 1 × 3/8" |
| Length | 654 mm |
| Width | 290 mm |
| Height | 156 mm |
| Weight | 8.3 kg |
| Included Eyepieces | 2 × 20mm 62° LER Waterproof EPs |
| Included Accessories | Built-in Carry Handle, Dew Caps |
Warranty
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Free Lifetime Collimation Service – Explore Scientific offers complimentary collimation for the life of the binoculars. Customers are responsible for shipping both ways.
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1-Year Limited Warranty – To activate, simply register your product within 60 days of purchase at explorescientific.com.