{"product_id":"svbony-sv109-m42-variable-extension-tube","title":"SVBONY SV109 M42 (T2) Variable Extension Tube (24–35 mm)","description":"\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6387056507705877491635536.jpg?v=1791669830\" alt=\"SVBONY SV109 M42 variable extension tube 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 SV109 M42 (item F9180A) is a variable-length T2 extension tube with M42×0.75 male and female threads. It adjusts from 24 mm to 35 mm, giving you continuous control of the spacing behind a reducer or field flattener, or of focus position in a camera or eyepiece train. The body is all-metal with an anodized aluminium finish.\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/f9180a-1_20250807155418_9571_20260810154556_6734.webp?v=1791670127\" alt=\"SVBONY SV109 M42 variable extension tube\" 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 your imaging train is M42\/T2-threaded and you need to hit a corrector's backfocus precisely, or you want an adjustable spacer for focus and framing.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eKey Features \u0026amp; Design\u003c\/strong\u003e\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAdjustable 24–35 mm:\u003c\/strong\u003e continuous spacing without stacking fixed rings.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eM42×0.75 (T2) male and female threads:\u003c\/strong\u003e connects cameras, eyepiece adapters and other T2 accessories.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAll-metal, anodized aluminium:\u003c\/strong\u003e for long-term durability.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6387056507743767088378019.jpg?v=1791669830\" alt=\"SVBONY SV109 M42 extension tube construction graphic\" style=\"max-width:100%;height:auto;\"\u003e\u003c\/p\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6387056507810908498804469.jpg?v=1791669830\" alt=\"SVBONY SV109 M42 extension tube T2 thread graphic\" 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\u003eBackfocus tuning\u003c\/strong\u003e behind M42 reducers and field flatteners.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFocus adjustment\u003c\/strong\u003e for astrophotography or visual trains.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/6387056507843238929104658.jpg?v=1791669830\" alt=\"SVBONY SV109 M42 extension tube adjustment graphic\" 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\u003eThreads:\u003c\/strong\u003e M42×0.75 (T2) male and female.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpacing:\u003c\/strong\u003e add 24–35 mm to your camera's flange distance and any filter holder to reach your corrector's backfocus. Send us your setup and we will work the figure out with you.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/f9180a-2_20250807155419_0256.jpg?v=1791670126\" alt=\"SVBONY SV109 M42 variable extension tube detail\" 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\u003eMechanical spacer only:\u003c\/strong\u003e no glass.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMinimum length 24 mm:\u003c\/strong\u003e shorter gaps need fixed M42 spacers.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e SVBONY does not publish a weight for this item.\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. Thread it between your corrector and camera, adjust the length to your target spacing, and lock it.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the adjustment range?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e24 mm to 35 mm.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs there an M48 version?\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eYes, SVBONY makes the SV109 in an M48 version as a separate product.\u003c\/p\u003e\u003ch3\u003e\u003cstrong\u003eBottom Line\u003c\/strong\u003e\u003c\/h3\u003e\u003cp\u003eIn short: an all-metal M42×0.75 (T2) extension tube that adjusts from 24 to 35 mm for precise backfocus and focus spacing.\u003c\/p\u003e","brand":"SvBony","offers":[{"title":"Default Title","offer_id":67722230136943,"sku":"F9180A","price":28.49,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0686\/0049\/6239\/files\/f9180a-1_20250807155418_9571_20260810154556_6734.webp?v=1791670127","url":"https:\/\/ontariotelescope.com\/products\/svbony-sv109-m42-variable-extension-tube","provider":"Ontario Telescope and Accessories","version":"1.0","type":"link"}