{"product_id":"svbony-sv158-75mm-extension-tube-2in","title":"SVBONY SV158 75mm Extension Tube - 2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e2-Inch Barrel Diameter\u003c\/li\u003e\n\u003cli\u003eCNC-Machined Aluminum Alloy\u003c\/li\u003e\n\u003cli\u003eBlack Anodized Finish\u003c\/li\u003e\n\u003cli\u003eAdds Back Focus for Imaging\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 SV158 75mm Extension Tube 2 inch\u003c\/h2\u003e\n\u003cp\u003eThe SVBONY SV158 75mm Extension Tube 2 inch provides the critical back focus needed for imaging trains or eyepieces that cannot reach focus within your telescope's standard travel. Designed for any system using 2-inch accessories, it bridges the gap when your camera sensor or field flattener sits too far back. Constructed from black aluminum alloy, it maintains a rigid, non-flexing connection in any 2-inch focuser or visual back.\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\u003eCNC-Machined Construction for 2-Inch Focusers\u003c\/h3\u003e\n\u003cp\u003eThe SV158 is CNC-machined from a single piece of black aluminum alloy, ensuring a solid and secure fit in your optical train. This rigid construction prevents the flexure and tilt that can ruin an image, which is critical when supporting cameras or other heavy accessories at the end of a 2-inch focuser.\u003c\/p\u003e\n\u003cp\u003eBy extending the focal plane outwards, this tube allows you to achieve a sharp image with accessories that require more back focus than your telescope natively provides. It is an essential component for many astrophotography setups, especially when combining focal reducers, off-axis guiders, and filter wheels.\u003c\/p\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\"\u003eWhy do I need the SVBONY SV158 Extension Tube for my telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYou need the SVBONY SV158 when your camera, focal reducer, or certain eyepieces cannot reach focus because the telescope's focuser lacks sufficient \"out-travel\". This tube adds the necessary physical distance to push the focal plane out, bringing these accessories into sharp focus.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the SVBONY SV158 Extension Tube help me reach focus with my DSLR on an 8\" SCT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, this is a very common application. An 8\" Schmidt-Cassegrain often has limited out-travel, and when you attach a T-ring and DSLR, the camera's sensor is positioned too far back. The SVBONY SV158 provides the extension required to push the focal plane out to meet the DSLR sensor.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the SVBONY SV158 Extension Tube made of?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe SVBONY SV158 is constructed from durable, \u003cstrong\u003eCNC-machined aluminum alloy\u003c\/strong\u003e. It features a black anodized finish to minimize internal reflections and maintain high contrast in your images.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eI'm trying to use a planetary camera with a Barlow lens, but the image is blurry. Can the SVBONY SV158 help?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt can. Adding a Barlow lens to your optical train pushes the focal point further out from the focuser. If you cannot rack your focuser out far enough to compensate, the SVBONY SV158 Extension Tube will provide the extra spacing needed to achieve a sharp image of planets like Jupiter or Saturn.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the SVBONY SV158 Extension Tube add any optics to the light path?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, it is a purely mechanical spacer. The SVBONY SV158 contains no lenses or glass, so it does not alter the focal length or optical properties of your telescope. It only extends the position of the focal plane.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eAre there any downsides to using the SVBONY SV158 Extension Tube?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile essential for reaching focus, adding any extension increases the leverage on your focuser. With heavy cameras or accessory stacks, you must ensure your focuser can handle the extra weight and moment arm without sagging or tilting, which could harm image quality.\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\u003eBarrel Size\u003c\/td\u003e\n\u003ctd\u003e2''\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaterial\u003c\/td\u003e\n\u003ctd\u003eAluminum Alloy\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eColor\u003c\/td\u003e\n\u003ctd\u003eBlack\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\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eSVBONY SV158 75mm Extension Tube 2 inch\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\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 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"SVBONY","offers":[{"title":"Default Title","offer_id":52861243523357,"sku":"SV-W9119A","price":19.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/SVBONY-SV158-75mm-Extension-Tube-2-inch-1_e1a1311b-271e-46b5-8e4e-0ee8e6b94176.jpg?v=1788660528","url":"https:\/\/davidastro.com\/products\/svbony-sv158-75mm-extension-tube-2in","provider":"David Astro","version":"1.0","type":"link"}