{"product_id":"m48-extension-tube-15-mm-m48x075-male-to-female-spacer","title":"M48 Extension Tube – 15 mm (M48x0.75 Male to Female Spacer)","description":"\u003ch3 data-start=\"103\" data-end=\"132\"\u003e\u003cstrong data-start=\"107\" data-end=\"130\"\u003eProduct Description\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-start=\"133\" data-end=\"524\"\u003eThis precision-machined \u003cstrong data-start=\"157\" data-end=\"185\"\u003e15 mm M48 Extension Tube\u003c\/strong\u003e is designed to provide an exact increase in optical path length for fine-tuning backfocus in astrophotography systems. Featuring \u003cstrong data-start=\"315\" data-end=\"392\"\u003eM48x0.75 male threads on one end and M48x0.75 female threads on the other\u003c\/strong\u003e, this spacer integrates seamlessly with any accessory, camera, or reducer\/flattener that uses the standard 2\" filter-thread format.\u003c\/p\u003e\n\u003cp data-start=\"526\" data-end=\"843\"\u003eConstructed from high-grade anodized aluminum, the tube offers excellent rigidity, smooth threading, and long-term durability even under frequent configuration changes. Its internal surface is fully blackened to minimize reflections, enhancing image contrast and reducing unwanted stray light in fast optical systems.\u003c\/p\u003e\n\u003cp data-start=\"845\" data-end=\"1190\"\u003eUse this extension when dialing in backfocus for reducers, flatteners, or correctors, or when achieving the ideal spacing between filters, tilt adjusters, off-axis guiders, and imaging sensors. At a true \u003cstrong data-start=\"1049\" data-end=\"1073\"\u003e15 mm optical length\u003c\/strong\u003e, it provides reliable and repeatable spacing with no added optical elements—just clean, simple mechanical extension.\u003cbr\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003ctable style=\"width: 99.9988%;\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth style=\"text-align: left; width: 24.344%;\"\u003e\n\u003ch2\u003eSpecification\u003c\/h2\u003e\n\u003c\/th\u003e\n\u003cth style=\"width: 75.3842%;\"\u003e\u003cbr\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 24.344%;\"\u003e\u003cstrong\u003eThread Size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 75.3842%;\"\u003eM48 × 0.75 (male to female)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 24.344%;\"\u003e\u003cstrong\u003eOptical Length\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 75.3842%;\"\u003e15 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 24.344%;\"\u003e\u003cstrong\u003eMechanical Length\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 75.3842%;\"\u003e15 mm (excluding threads)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 24.344%;\"\u003e\u003cstrong\u003eClear Aperture\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 75.3842%;\"\u003e45 mm depending on step-in geometry\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 24.344%;\"\u003e\u003cstrong\u003eMaterial\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 75.3842%;\"\u003eCNC-machined aluminum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 24.344%;\"\u003e\u003cstrong\u003eFinish\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 75.3842%;\"\u003eHard anodized, matte black\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 24.344%;\"\u003e\u003cstrong\u003eInternal Treatment\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 75.3842%;\"\u003eBlack-matte, anti-reflection internal surface\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 24.344%;\"\u003e\u003cstrong\u003eUse Case\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 75.3842%;\"\u003eBackfocus spacing, threaded extension, imaging train optimization\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 24.344%;\"\u003e\u003cstrong\u003eCompatibility\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 75.3842%;\"\u003eAny accessories using \u003cmeta charset=\"utf-8\"\u003eM48 × 0.75 threads (filter drawers, correctors, OAGs, cameras, etc.)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Starizona","offers":[{"title":"Default Title","offer_id":52412609102114,"sku":"sqo1787928457347","price":15.79,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0944\/2249\/9618\/files\/m48-extension-tube-15-mm-m48x075-male-to-female-spacer_1.png?v=1787928463","url":"https:\/\/mossmerton.com\/products\/m48-extension-tube-15-mm-m48x075-male-to-female-spacer","provider":"Mossmerton","version":"1.0","type":"link"}