{"product_id":"svbony-f9157-66-degree-ultra-wide-eyepiece","title":"SVBONY 66° Ultra Wide Eyepiece 1.25″ (6, 9, 15, 20 mm)","description":"\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6373103537233876538947073.jpg?v=1791669969\" alt=\"SVBONY F9157 66 degree ultra wide 1.25″ eyepiece overview\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe SVBONY F9157 series are 1.25″ ultra-wide eyepieces with a 66° apparent field of view and 16 mm of eye relief across the range, in 6 mm (F9157A), 9 mm (F9157B), 15 mm (F9157C) and 20 mm (F9157D) focal lengths. The optics are fully multi-coated, the optic edges and interior are blackened, and the aluminium barrels have a two-step anodized matte finish and threads for 1.25″ filters. A fold-down rubber eyecup works with or without glasses.\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6373103540893031306442761.jpg?v=1791669969\" alt=\"SVBONY F9157 66 degree eyepiece optics and field of view\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eWho It's For\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThis is a good match if you want a wider field than a Plössl with comfortable eye relief, including if you observe with glasses, across a range that covers low, medium and high power.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e66° apparent field:\u003c\/strong\u003e a wide view for lunar, cluster and nebula observing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e16 mm eye relief on every focal length:\u003c\/strong\u003e the same comfortable eye position throughout the set.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFully multi-coated optics:\u003c\/strong\u003e for bright, true-colour views.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBlackened edges and interior:\u003c\/strong\u003e reduce stray light and internal reflections.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1.25″ filter thread:\u003c\/strong\u003e takes SVBONY and other standard 1.25″ filters.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFold-down eyecup:\u003c\/strong\u003e for use with or without eyeglasses.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6373103542190598665903451.jpg?v=1791669969\" alt=\"SVBONY F9157 66 degree eyepiece lens group design\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eOptical Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eEach focal length uses its own multi-element design: 5 elements in 3 groups for the 6 mm, 6 elements in 4 groups for the 9 mm, 4 elements in 3 groups for the 15 mm, and 5 elements in 3 groups for the 20 mm. The extra elements over a four-element Plössl are what allow the wider 66° field and the constant 16 mm eye relief, particularly at the short focal lengths where a Plössl's eye relief becomes very tight.\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6373103544238055389881702.jpg?v=1791669969\" alt=\"SVBONY F9157 66 degree eyepiece blackened interior and filter thread\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eRecommended Uses\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e6 mm and 9 mm:\u003c\/strong\u003e the Moon and planets at high and medium-high power.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e15 mm:\u003c\/strong\u003e star clusters, lunar overviews and planetary nebulae.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e20 mm:\u003c\/strong\u003e wide views of nebulae, clusters and star fields.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6373103552846521428883771.jpg?v=1791669969\" alt=\"SVBONY F9157 66 degree eyepiece fold-down eyecup and body\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eCompatibility and Accessory Notes\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBarrel:\u003c\/strong\u003e 1.25″, for any 1.25″ focuser or diagonal.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFilters:\u003c\/strong\u003e threaded for standard 1.25″ filters.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFocal length:\u003c\/strong\u003e this listing is currently set up for the 6 mm (F9157A); contact us for the 9, 15 or 20 mm, or the set, while we add them.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6373103548155555661563582.jpg?v=1791669969\" alt=\"SVBONY F9157 66 degree eyepiece range 6mm 9mm 15mm 20mm\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eGood to Know Before You Order\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh power and seeing:\u003c\/strong\u003e the 6 mm gives high magnification, which is most rewarding on steady nights.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e SVBONY does not publish a weight for these eyepieces.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eIs it difficult to set up?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eNo. It slides into a 1.25″ focuser or diagonal like any eyepiece; tighten the thumbscrew and focus.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use it with glasses?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eYes. The 16 mm eye relief and fold-down eyecup are designed for observing with or without eyeglasses.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat magnification will each give?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eDivide your telescope's focal length by the eyepiece focal length. On a 1000 mm telescope: 167x (6 mm), 111x (9 mm), 67x (15 mm) and 50x (20 mm).\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: 1.25″ fully multi-coated eyepieces with a 66° field and 16 mm eye relief throughout, in 6, 9, 15 and 20 mm, for the Moon, planets and deep sky.\u003c\/p\u003e","brand":"SvBony","offers":[{"title":"6 mm","offer_id":67722351116399,"sku":"F9157A","price":45.6,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/f9157_20250806175622_2795_20260810142812_2172.webp?v=1791670671","url":"https:\/\/ontariotelescope.com\/products\/svbony-f9157-66-degree-ultra-wide-eyepiece","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}