{"product_id":"bt-120-sf-large-binoculars-with-62-degree-ler-eyepieces","title":"BT-120 SF Large Binoculars with 62 Degree LER Eyepieces","description":"\u003ch1\u003eBT-120 SF Large Binoculars with 62 Degree LER Eyepieces\u003c\/h1\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eDescription\u003c\/h2\u003e\n\u003cp\u003e\n  The Explore Scientific BT-120 SF Giant Binoculars are a premium optical instrument that brings the light-gathering power of a double refractor telescope into a binocular form factor - delivering stunningly bright, detailed views for both astronomy and terrestrial observation. With a massive 120mm objective diameter and 660mm focal length, these binoculars resolve lunar craters, planets, bright deep-sky objects, and distant landscapes with remarkable clarity and contrast. The 45-degree ergonomic viewing angle, soft silicone eyecups, and helical individual focusing system make extended observing sessions genuinely comfortable, whether you're stargazing or scanning a wildlife reserve.\n\u003c\/p\u003e\n\u003cp\u003e\n  Built to professional standards, the BT-120 SF features a sealed, nitrogen-filled magnesium housing that is fully waterproof and fog-proof, ready for any outdoor conditions. The included 62° 20mm LER eyepieces provide a wide apparent field of view with 15mm of eye relief, and the 1.25\" plug-in eyepiece system allows easy swapping for different magnifications. Whether you're an amateur astronomer, a dedicated birder, or a nature enthusiast, the BT-120 SF represents a serious upgrade in immersive, wide-field optical performance.\n\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003e120mm Objective Diameter:\u003c\/strong\u003e Massive light-gathering aperture reveals fine detail on the moon, planets, and deep-sky objects invisible to smaller binoculars.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e660mm Focal Length \/ f\/5.5 Focal Ratio:\u003c\/strong\u003e Achromatic refractor Porro optical design delivers bright, high-contrast images across astronomy and terrestrial use.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e62° Apparent Field of View:\u003c\/strong\u003e Wide-field 20mm LER eyepieces included, providing immersive views with a 1.8-degree real field of view.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e15mm Long Eye Relief (LER):\u003c\/strong\u003e Comfortable viewing for eyeglass wearers and extended sessions, with soft adjustable silicone eyecups.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e1.25\" Interchangeable Eyepiece System:\u003c\/strong\u003e Plug-in eyepiece compatibility with brass compression ring clamps lets you swap magnifications without tools or alignment headaches.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003e45-Degree Viewing Angle:\u003c\/strong\u003e Ergonomic angled eyepiece design reduces neck fatigue during long astronomy or birding sessions.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMagnesium Housing - Sealed and Nitrogen-Filled:\u003c\/strong\u003e Waterproof (IPX6) and fog-proof in any weather; rugged enough for field and travel use.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eExtendable Dew Caps:\u003c\/strong\u003e Prevent lens condensation during cold-weather or damp observing conditions.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eEnhanced Multilayer Deposition (EMD) Coatings:\u003c\/strong\u003e Professional-grade coatings on all optical surfaces maximize light transmission and image brightness.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMultiple Tripod Connection Options:\u003c\/strong\u003e Central carrying handle and multiple mount points; compatible with the optional Explore Scientific U-Mount with field tripod for optimal stability.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eWhat's Included\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003eBT-120 SF Large Binocular body\u003c\/li\u003e\n  \u003cli\u003eTwo 62° 20mm LER eyepieces (1.25\" plug-in)\u003c\/li\u003e\n  \u003cli\u003eSoft silicone eyecups\u003c\/li\u003e\n  \u003cli\u003eExtendable dew caps\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eWhy You'll Love It\u003c\/h2\u003e\n\u003cp\u003e\n  The Explore Scientific BT-120 SF is the kind of instrument that turns a casual stargazing night into a genuine observing event - trusted by astronomy enthusiasts, nature observers, and serious birders who demand professional-grade optics without compromise. The combination of a 120mm aperture and wide 62° eyepieces creates a deeply immersive experience that smaller binoculars simply cannot replicate. Its all-weather magnesium construction means you can take it to a dark-sky site, a coastal wetland, or a mountain overlook with full confidence in its durability. The ergonomic 45-degree viewing angle and fatigue-free focusing system mean you and your group can spend hours at the eyepiece without discomfort. With the flexibility of interchangeable 1.25\" eyepieces and optional nebula and color filters, the BT-120 SF grows with your observing interests and continues to reward you for years to come. For anyone ready to take their visual astronomy or nature observation to the next level, this is the instrument that delivers.\n\u003c\/p\u003e\n\n\u003chr\u003e\n\n\u003ch2\u003eProduct Specifications\u003c\/h2\u003e\n\u003cdiv class=\"custom-product-faq\"\u003e\n\u003cdetails\u003e\n\u003csummary\u003e\u003cstrong\u003eView Product Specs\u003c\/strong\u003e\u003c\/summary\u003e\n\u003ctable border=\"1\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eItem Number\u003c\/th\u003e\n\u003ctd\u003e01-14230\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eOptical Design\u003c\/th\u003e\n\u003ctd\u003eAchromatic Refractor Porro\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eObjective Diameter\u003c\/th\u003e\n\u003ctd\u003e120 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFocal Length\u003c\/th\u003e\n\u003ctd\u003e660 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFocal Ratio\u003c\/th\u003e\n\u003ctd\u003ef\/5.5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eApparent Field of View\u003c\/th\u003e\n\u003ctd\u003e62 degrees\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eReal Field of View\u003c\/th\u003e\n\u003ctd\u003e1.8 degrees\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eCoating Type\u003c\/th\u003e\n\u003ctd\u003eEnhanced Multilayer Deposition (EMD)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eExit Pupil (min)\u003c\/th\u003e\n\u003ctd\u003e3.6 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eEye Relief\u003c\/th\u003e\n\u003ctd\u003e15 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWaterproof\u003c\/th\u003e\n\u003ctd\u003eYes - IPX6\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eHousing Material\u003c\/th\u003e\n\u003ctd\u003eMagnesium (sealed, nitrogen-filled)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eTotal Length\u003c\/th\u003e\n\u003ctd\u003e654 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eTotal Width\u003c\/th\u003e\n\u003ctd\u003e290 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eTotal Height\u003c\/th\u003e\n\u003ctd\u003e156 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eNet Weight\u003c\/th\u003e\n\u003ctd\u003e8,300 g\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e\u003ch2\u003eFAQ\u003c\/h2\u003e\n\u003cdiv class=\"custom-product-faq\"\u003e\n\u003cdetails\u003e\n\u003csummary\u003eDo I need a tripod to use the BT-120 SF?\u003c\/summary\u003e\n\u003cp class=\"faq-content\"\u003eYes - at 8,300g (over 18 lbs), the BT-120 SF is a giant binocular designed for tripod or mount use, not handheld viewing. Multiple tripod connection points are built into the central carrying handle. For the best experience, the optional Explore Scientific U-Mount with field tripod is highly recommended, as it is specifically designed to support large binoculars like this model and allows smooth, comfortable viewing at the 45-degree eyepiece angle.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan I use these binoculars with eyeglasses?\u003c\/summary\u003e\n\u003cp class=\"faq-content\"\u003eYes. The included 62° 20mm LER eyepieces feature 15mm of long eye relief, which is comfortable for most eyeglass wearers. The soft silicone eyecups are also adjustable, allowing you to fold them down to achieve the correct eye distance whether or not you wear glasses.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan I change the magnification on the BT-120 SF?\u003c\/summary\u003e\n\u003cp class=\"faq-content\"\u003eAbsolutely. The BT-120 SF uses a 1.25\" plug-in eyepiece system, meaning you can swap the included 20mm eyepieces for other compatible 1.25\" eyepieces to change magnification. Explore Scientific offers several eyepieces in their 62° waterproof series - including 5.5mm, 14mm, and 26mm options - giving you a wide range of magnification choices for different targets.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eAre these binoculars good for both astronomy and daytime use?\u003c\/summary\u003e\n\u003cp class=\"faq-content\"\u003eYes. The BT-120 SF is explicitly designed for both astronomical and terrestrial observation. The 120mm aperture gathers tremendous light for night-sky viewing of the moon, planets, and deep-sky objects, while the wide field of view and sharp optics make it equally impressive for birding, wildlife watching, and scenic landscape viewing during the day.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eWhat does IPX6 waterproof rating mean?\u003c\/summary\u003e\n\u003cp class=\"faq-content\"\u003eIPX6 means the binoculars are protected against powerful water jets from any direction - essentially rain, heavy splashing, and similar wet conditions will not damage the optics or internal components. The sealed, nitrogen-filled magnesium housing also prevents internal fogging when moving between temperature extremes, making the BT-120 SF suitable for use in genuinely demanding outdoor environments.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003cdetails\u003e\n\u003csummary\u003eCan I use color or nebula filters with the BT-120 SF?\u003c\/summary\u003e\n\u003cp class=\"faq-content\"\u003eYes. The 1.25\" plug-in eyepiece system supports optional color and nebula filters, which can be threaded onto compatible eyepieces to enhance contrast on specific astronomical targets such as nebulae, planets, and the moon. These filters are sold separately.\u003c\/p\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e","brand":"Explore Scientific","offers":[{"title":"Default Title","offer_id":55918236467505,"sku":"01-14230","price":2499.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1724\/7681\/files\/2c434c58450323676f8cb215705793e7_0114230_m_1.jpg?v=1787663236","url":"https:\/\/omahasportsandgames.com\/products\/bt-120-sf-large-binoculars-with-62-degree-ler-eyepieces","provider":"Omaha Sports \u0026 Games","version":"1.0","type":"link"}