{"product_id":"baader-planetarium-adapter-m55a-to-m68i","title":"Baader Planetarium Adapter M55a to M68i","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eAdapts M55 External (M55a) Threads\u003c\/li\u003e\n\u003cli\u003eProvides a Secure M68 Internal (M68i) Thread\u003c\/li\u003e\n\u003cli\u003eEnables Connection to the Baader M68 System\u003c\/li\u003e\n\u003cli\u003eDesigned for Specific Baader Mirrors and Diagonals\u003c\/li\u003e\n\u003cli\u003ePrevents Vignetting with Large Format Sensors\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\u003eAdapter M55a to M68i\u003c\/h2\u003e\n\u003cp\u003eThe Baader Planetarium Adapter M55a to M68i is a specialized expansion ring designed to integrate components into the larger, more robust Baader M68 optical system. It directly converts an M55 external thread into a secure M68 internal thread, opening up compatibility with a wide range of professional-grade accessories for serious imaging.\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\u003eConvert M55 Threads to the M68 System for Secure Imaging\u003c\/h3\u003e\n\u003cp\u003eThis adapter serves a critical function: bridging the gap between components using the M55 thread and the versatile Baader M68 system. By providing a secure M68 internal thread, you can create a rigid, wide-aperture connection for your imaging train. This is essential for attaching M68 accessories like off-axis guiders, filter wheels, or spacers without introducing flexure or vignetting, especially when using cameras with large sensors.\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\u003eInstallation Note: Face Spanner #2450062 Recommended\u003c\/h3\u003e\n\u003cp\u003eProper installation of this adapter on compatible Baader mirrors or diagonals requires a specific procedure. You must first unthread and remove the standard 2\" barrel and the M55 \/ 2\" UNC threaded ring from the component's housing. Baader Planetarium recommends using their Face Spanner (#2450062) to safely perform this task before threading on the M55a to M68i adapter.\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\"\u003eWhat is the primary use for the Baader M55a to M68i Adapter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Baader M55a to M68i Adapter is used to connect accessories with an M55 external thread to the Baader M68 system, providing a larger, more secure M68 internal thread. This is ideal for building rigid, wide-aperture imaging trains that minimize vignetting and prevent flexure.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I need a special tool to install the M55a to M68i Adapter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, proper installation often requires a specific tool. To fit this adapter to a compatible Baader mirror or diagonal, you must first remove the existing 2\" barrel and M55 retaining ring. Baader strongly recommends using their \u003cstrong\u003eFace Spanner (#2450062)\u003c\/strong\u003e for this task to avoid damage.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill this adapter help reduce vignetting in my imaging setup with a Baader diagonal?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. By converting the connection to the larger M68 standard, this adapter provides a wider, un-obstructed light path compared to a standard 2\" nosepiece or a smaller M55 thread. This is a key benefit for minimizing vignetting, especially when imaging with large-format APS-C or full-frame camera sensors.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the M55a to M68i Adapter help when imaging galaxies like Andromeda (M31) with a large sensor camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhen imaging large targets like the Andromeda Galaxy (M31) with a full-frame or APS-C sensor, maintaining an unvignetted field is critical. This adapter allows you to build a complete M68 threaded imaging train from your diagonal to the camera, ensuring the light cone is not clipped by smaller adapters, resulting in more evenly illuminated images across the entire frame.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of accessories can I attach after installing the M55a to M68i Adapter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eOnce installed, your component will have a female M68 thread, allowing you to attach any accessory from the Baader M68 system. This includes the M68 Off-Axis Guider, M68 filter changers, or various M68 extension tubes needed to achieve precise back focus distances.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs this adapter the same as a standard step-up ring?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt is more specialized. While it functions as a step-up ring (M55 to M68), it is specifically engineered to replace the 2\" barrel assembly on certain Baader components. This makes it an integrated part of the optical system rather than a simple, generic add-on adapter.\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\u003e0.03\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\u003e51\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType of Adapter\u003c\/td\u003e\n\u003ctd\u003eReducing Adapter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical length (mm)\u003c\/td\u003e\n\u003ctd\u003e8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInner Connection (eyepiece\/-camera-sided)\u003c\/td\u003e\n\u003ctd\u003eM68 x 1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOuter Connection (lens sided)\u003c\/td\u003e\n\u003ctd\u003eM55\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAdapters Family\u003c\/td\u003e\n\u003ctd\u003eM68 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\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Baader_Planetarium_Star_Diagonals_T-2_and_2in_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eBaader Planetarium Star Diagonals T-2 and 2in Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\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":52913175134493,"sku":"BAA-2458234","price":69.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/BaaderPlanetarium-Adapter-M55a-to-M68i-1_a3d45c44-d399-44e7-8726-1d10e7b2ff74.jpg?v=1789087210","url":"https:\/\/davidastro.com\/products\/baader-planetarium-adapter-m55a-to-m68i","provider":"David Astro","version":"1.0","type":"link"}