{"product_id":"baader-planetarium-m48a-change-ring-with-s48a-ring-dovetail","title":"Baader Planetarium M48a Change Ring with S48a ring dovetail","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eConverts M48 threads to the Baader S48a dovetail standard\u003c\/li\u003e\n\u003cli\u003eEnables rapid, secure attachment and detachment of accessories\u003c\/li\u003e\n\u003cli\u003eProvides a rigid, non-rotating connection to prevent camera tilt\u003c\/li\u003e\n\u003cli\u003eDesigned for minimal optical path length to preserve back focus\u003c\/li\u003e\n\u003cli\u003ePart of the Baader M48 Quick Change System\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\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\u003eM48a Change Ring with S48a ring dovetail\u003c\/h2\u003e\n\u003cp\u003eThe Baader M48a Change Ring with S48a ring dovetail is a core component of the Baader Quick Change System, engineered to convert standard M48 filter threads into a fast, rigid, and repeatable connection. This ring allows for the rapid swapping of cameras and accessories without the risk of thread binding or altering your critical rotational alignment, streamlining your imaging sessions.\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\u003eSecure M48 Connections for a Modular Imaging Train\u003c\/h3\u003e\n\u003cp\u003eFor astrophotographers, threaded connections are a common source of flexure, tilt, and frustration in the dark. The Baader M48a Change Ring solves this by replacing the M48 thread with a secure S48a dovetail, which locks into the corresponding Baader M48 Quick Changer (#2958548) for a solid, repeatable fit.\u003c\/p\u003e\n\u003cp\u003eThis system is designed for modularity. By attaching a Change Ring to each of your M48-threaded components—such as a camera nosepiece, an off-axis guider, or a filter drawer—you can instantly switch between different imaging configurations without the tedious and error-prone process of unthreading gear in the field.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eZero-Flexure Interface:\u003c\/strong\u003e The S48a dovetail provides a wide, rigid contact surface that prevents the tilt and sag common with single-point threaded connections, ensuring your optical train remains perfectly aligned.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePreserves Back Focus:\u003c\/strong\u003e The ring is designed with a minimal optical path length, allowing it to be integrated into tight imaging trains without consuming your available back focus.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRepeatable Orientation:\u003c\/strong\u003e Once locked in, your camera and accessories return to the exact same rotational angle every time. This is critical for maintaining flat-frame calibration and consistent framing across multiple nights.\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 primary purpose of the Baader M48a Change Ring?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Baader M48a Change Ring is designed to convert an accessory's male M48 thread into the female S48a dovetail. This makes the accessory compatible with the Baader M48 Quick Changer, allowing you to attach and detach it from your telescope quickly and securely without rotating it or dealing with fine threads.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the M48a Change Ring improve imaging with a coma corrector on a Newtonian?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt allows you to detach your camera from the coma corrector without unthreading it. This is crucial because it \u003cstrong\u003epreserves the precise rotational alignment\u003c\/strong\u003e needed for optimal corner-star correction. You can easily remove the camera to check focus or add accessories and reattach it, knowing the orientation is unchanged.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the Baader M48a Change Ring add significant length to the optical path?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, it is designed to be very thin, adding only a minimal amount of optical length. This is essential for maintaining the correct back focus distance required by most field flatteners, reducers, and coma correctors.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use this M48a Change Ring to connect a full-frame camera to my SCT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The M48 thread format is ideal for full-frame sensors as it provides a wider, unvignetted light path compared to T2 threads. This change ring allows you to integrate your full-frame camera into a rigid, quick-release system, which is especially useful with Schmidt-Cassegrain telescopes that often have M48-threaded reducers or adapters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat other part do I need to use the Baader M48a Change Ring?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis M48a Change Ring (#2958547) is the accessory-side component. To create a complete system, you must pair it with the telescope-side \u003cstrong\u003eBaader M48 Quick Changer (#2958548)\u003c\/strong\u003e, which contains the locking mechanism that clamps onto this ring's dovetail.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the Baader M48a Change Ring allow for rotation after it's locked?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, and that is its key feature. Once the S48a dovetail is locked into the changer, the connection is fixed and non-rotational. This prevents your camera from rotating under its own weight and ensures your guide camera and imaging camera maintain their relative orientation.\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\u003eNet weight (kg)\u003c\/td\u003e\n\u003ctd\u003e0.04\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatible Brands\u003c\/td\u003e\n\u003ctd\u003eBaader Planetarium\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInner Diameter \/ Clear Aperture (mm)\u003c\/td\u003e\n\u003ctd\u003e44 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOuter Diameter\u003c\/td\u003e\n\u003ctd\u003e59 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType of Adapter\u003c\/td\u003e\n\u003ctd\u003eSame-Thread Adapter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical length (mm)\u003c\/td\u003e\n\u003ctd\u003e4\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOuter Connection (lens sided)\u003c\/td\u003e\n\u003ctd\u003eM48\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAdapters Family\u003c\/td\u003e\n\u003ctd\u003eM48 System\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\u003ca href=\"https:\/\/davidastro.com\/pages\/baader-planetarium-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eBaader Planetarium Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Baader Planetarium","offers":[{"title":"Default Title","offer_id":52913157701917,"sku":"BAA-2958595","price":61.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/BaaderPlanetarium-M48a-Change-Ring-with-S48a-ring-dovetail-1_097ab9cd-07aa-4d01-8353-653890b59470.jpg?v=1789086866","url":"https:\/\/davidastro.com\/en-us\/products\/baader-planetarium-m48a-change-ring-with-s48a-ring-dovetail","provider":"David Astro","version":"1.0","type":"link"}