{"product_id":"svbony-sv135-7-21mm-zoom-eyepiece-60-40","title":"SVBONY SV135 1.25″ 7–21mm 60°–40° Zoom Eyepiece","description":"\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6387599343670693111174393.jpg?v=1791669869\" alt=\"SVBONY SV135 7-21mm 60-40 degree zoom eyepiece key visual\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eProduct Overview\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eThe SVBONY SV135 60°–40° (item W9105D) is a fully multi-coated 1.25″ zoom eyepiece that runs continuously from 7 mm to 21 mm. It is the widest-field SV135, with a 60° apparent field at 7 mm and 40° at 21 mm, from seven elements in four groups of high-index glass. Eye relief is 13–15 mm, the barrel has an M28.5 × 0.6 filter thread, and it weighs 145 g.\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6387599343704293863361889.jpg?v=1791669868\" alt=\"SVBONY SV135 7-21mm 60-40 degree zoom eyepiece optical design\" 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 one eyepiece for the Moon, Jupiter and Saturn, nebulae and star clusters, and you value a wider field at high power — helpful for keeping a planet in view longer on a manual or undriven mount.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e7–21 mm linear zoom\u003c\/strong\u003e with a 60°–40° apparent field.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e4 groups \/ 7 elements:\u003c\/strong\u003e fully multi-coated high-index glass.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e13–15 mm eye relief:\u003c\/strong\u003e rubber eye guard for comfort with glasses and to block stray light.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSafety undercut barrel:\u003c\/strong\u003e helps keep it seated in the focuser or diagonal.\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eBlackened lens edges and anti-reflection threads.\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM28.5 × 0.6 filter thread\u003c\/strong\u003e for 1.25″ accessories.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6387599343736592705505396.jpg?v=1791669869\" alt=\"SVBONY SV135 7-21mm 60-40 degree zoom eyepiece barrel and thread\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eOptical Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eWith seven elements in four groups, this SV135 holds a wider field across the zoom range than the five- and six-element versions: 60° at 7 mm, 40° at 21 mm. The trade is weight — 145 g against 95 g and 133 g for the other two. On a 1000 mm telescope it gives roughly 48× to 143×.\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/w9105d-2_20250807161957_0616.jpg?v=1791670293\" alt=\"SVBONY SV135 60-40 degree zoom eyepiece with rubber eye guard\" 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\u003eMoon and planets:\u003c\/strong\u003e Jupiter and Saturn at the power the seeing allows.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNebulae and star clusters,\u003c\/strong\u003e including diffuse nebulae, at the low-power end.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGrab-and-go and outreach:\u003c\/strong\u003e one eyepiece in place of several.\u003c\/li\u003e\n\u003c\/ul\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 standard 1.25″ focusers and diagonals.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFilters:\u003c\/strong\u003e M28.5 × 0.6 thread, compatible with 1.25″ filters.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/w9105d-3_20250807161957_0850.jpg?v=1791670293\" alt=\"SVBONY SV135 60-40 degree zoom eyepiece 1.25 inch barrel\" 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\u003eField narrows to 40° at 21 mm,\u003c\/strong\u003e as is typical of zooms.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThree SV135 versions:\u003c\/strong\u003e 52°–36°, 57°–40° and 60°–40° (this one), each with its own design and weight.\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; twist to zoom and refocus slightly as needed.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan I use it with glasses?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eThe 13–15 mm eye relief and rubber eye guard are designed for use with glasses.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhich SV135 has the widest field?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eThis one: 60° at 7 mm and 40° at 21 mm.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: a 145 g, 4-group\/7-element 1.25″ 7–21 mm zoom with a 60°–40° field — the widest-field SV135 for lunar, planetary and cluster observing.\u003c\/p\u003e","brand":"SvBony","offers":[{"title":"Default Title","offer_id":67722265264239,"sku":"W9105D","price":78.38,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/w9105d-0_20251231152231_0727.webp?v=1791670293","url":"https:\/\/ontariotelescope.com\/products\/svbony-sv135-7-21mm-zoom-eyepiece-60-40","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}