{"product_id":"svbony-sv216-2x-4-element-barlow-lens-125in","title":"SVBONY SV216 2X 4-Element Barlow Lens - 1.25\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e2x Magnification Factor\u003c\/li\u003e\n\u003cli\u003e4-Element Optical Design\u003c\/li\u003e\n\u003cli\u003e1.25 inch Barrel Size\u003c\/li\u003e\n\u003cli\u003e3-Screw Coaxial Clamping System\u003c\/li\u003e\n\u003cli\u003eFully Multicoated Lenses\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- more --\u003e\n\u003cul class=\"tabs\"\u003e\n\u003cli class=\"active\"\u003eDescription\u003c\/li\u003e\n\u003cli\u003eFAQ\u003c\/li\u003e\n\u003cli\u003eSpecifications\u003c\/li\u003e\n\u003cli\u003eIn the Box\u003c\/li\u003e\n\u003cli\u003eDownloads\u003c\/li\u003e\n\u003cli\u003eWarranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul class=\"tabs-content\"\u003e\n\u003cli class=\"active\"\u003e\n\u003cdiv\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section-center\"\u003e\n\u003ch2\u003eSVBONY SV216 1.25\" 2X 4-Element Barlow Lens for Planetary Astronomy\u003c\/h2\u003e\n\u003cp\u003eThe SVBONY SV216 1.25\" Barlow Lens doubles your telescope's effective focal length using an advanced 4-element optical design to maintain a flat, sharp field of view. Its coaxial clamp utilizes 3 M3x10 thumbscrews for precise optical alignment, and the barrel's M28.5x0.6 threads accept standard 1.25\" filters for enhanced planetary contrast.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e4-Element Optics: A Flat Field for 2x Magnification\u003c\/h3\u003e\n\u003cp\u003eUnlike standard 2-element Barlows, the SV216 uses a 4-element lens group to deliver superior optical correction. This design significantly reduces chromatic aberration and flattens the field, ensuring stars remain sharp points even at the edge of wide-angle eyepieces. Fully multicoated surfaces on all elements maximize light transmission for bright, high-contrast views of planetary details like Jupiter's Great Red Spot or the Cassini Division in Saturn's rings.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eCoaxial Alignment: The 3-Screw Clamping Mechanism\u003c\/h3\u003e\n\u003cp\u003eThe SV216 replaces the single-screw standard with a robust 3-screw clamping system. This design allows you to apply even pressure from multiple points, forcing the eyepiece barrel to align perfectly with the Barlow's optical axis. This coaxial alignment is critical for high-magnification imaging and viewing, preventing optical tilt that can soften an entire side of the image. A brass compression ring prevents the stainless steel thumbscrews from marring your eyepiece barrels.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eSV216 4-Element vs. Standard 2-Element Barlows\u003c\/h3\u003e\n\u003cp\u003eA standard 2-element achromatic Barlow, like a Celestron Omni, is often lighter and more affordable, making it a common entry-level choice. However, the optical and mechanical design of the SVBONY SV216 provides distinct advantages for serious planetary observation and imaging.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eEdge Correction:\u003c\/strong\u003e The SV216's 4-element design provides a flatter field, crucial for keeping details sharp across the larger sensors of modern planetary cameras or when using wide-field eyepieces.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor Fidelity:\u003c\/strong\u003e By better controlling chromatic aberration, the SV216 minimizes distracting color fringing on bright targets like the lunar limb, Venus, and Jupiter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMechanical Centering:\u003c\/strong\u003e The 3-screw clamp of the SV216 offers superior optical alignment compared to the single-screw design common on most 2-element Barlows, preventing image-degrading tilt. The trade-off is weight; at 7.72oz (219g), the SV216 is substantially heavier and may require rebalancing your telescope.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the main advantage of the SVBONY SV216's 4-element design?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary advantage of the \u003cstrong\u003e4-element design\u003c\/strong\u003e is superior optical correction compared to simpler 2-element Barlows. It produces a flatter field of view, meaning stars stay sharp closer to the edge, and it significantly reduces chromatic aberration (color fringing) on bright objects.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the 3-screw clamp on the SVBONY SV216 improve views?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e3-screw clamp\u003c\/strong\u003e ensures your eyepiece or camera is held perfectly on the optical axis (coaxially). A single thumbscrew can push the eyepiece slightly to one side, creating tilt that degrades sharpness, especially at high magnification. The SV216's design provides even pressure for a more precise, stable optical train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use filters with the SVBONY SV216 Barlow?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The 1.25\" barrel is threaded with standard \u003cstrong\u003eM28.5x0.6\u003c\/strong\u003e threads, allowing you to attach any standard 1.25\" filter. This is ideal for using color filters to enhance planetary features or a UV\/IR cut filter for imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the SVBONY SV216 work well for imaging Jupiter with my 8\" f\/10 SCT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. An 8\" SCT has a focal length around 2000mm. The \u003cstrong\u003eSVBONY SV216 2x Barlow\u003c\/strong\u003e will double this to 4000mm (f\/20), providing the ideal image scale for capturing fine detail in Jupiter's cloud bands with most modern planetary cameras. The flat-field 4-element design will keep the planet sharp across the entire sensor.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the SVBONY SV216 a good match for wide-angle eyepieces in my fast Dobsonian?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, it's an excellent match. Fast telescopes (f\/4-f\/5) and wide-angle eyepieces are very demanding on optics. The \u003cstrong\u003eSV216's 4-element design\u003c\/strong\u003e provides the necessary correction to control aberrations like coma and astigmatism at the edge of the field, which would be amplified by a simpler Barlow.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill I need to rebalance my telescope with the SVBONY SV216?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eMost likely, yes. The SVBONY SV216 weighs \u003cstrong\u003e7.72oz (219g)\u003c\/strong\u003e, which is significantly heavier than a standard eyepiece or a lightweight Barlow. You should expect to adjust your counterweights or tube position to maintain proper balance, especially on smaller mounts.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eSVBONY\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMagnification Factor\u003c\/td\u003e\n\u003ctd\u003e2x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBarrel Size\u003c\/td\u003e\n\u003ctd\u003e1.25 inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLens Elements\u003c\/td\u003e\n\u003ctd\u003e4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLens Coatings\u003c\/td\u003e\n\u003ctd\u003eFully multicoated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Threads\u003c\/td\u003e\n\u003ctd\u003eM28.5x0.6\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompression Ring\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBarrel Material\u003c\/td\u003e\n\u003ctd\u003eStainless Steel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBarrel Type\u003c\/td\u003e\n\u003ctd\u003eStraight Barrel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThumbscrews\u003c\/td\u003e\n\u003ctd\u003e3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThumbscrew Thread\u003c\/td\u003e\n\u003ctd\u003eM3x10\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInsertion Depth\u003c\/td\u003e\n\u003ctd\u003e1.55 inch \/ 39.5 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLength of Upper Body\u003c\/td\u003e\n\u003ctd\u003e2.34 inch \/ 59.5 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax Diameter\u003c\/td\u003e\n\u003ctd\u003e1.73 inch \/ 44 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNet Weight\u003c\/td\u003e\n\u003ctd\u003e7.72 oz \/ 219 g\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/svbony-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eSVBONY Warranty Policy\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"SVBONY","offers":[{"title":"Default Title","offer_id":52861236805917,"sku":"SV-W9168A","price":70.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/SVBONY-SV216-1-25-2X-4-Element-Barlow-Lens-for-Planetary-Astronomy-1_161fcb3c-059d-402a-82aa-b9880252a975.jpg?v=1788883577","url":"https:\/\/davidastro.com\/products\/svbony-sv216-2x-4-element-barlow-lens-125in","provider":"David Astro","version":"1.0","type":"link"}