{"product_id":"baader-planetarium-m68-varilock-extension-15-20-mm","title":"Baader Planetarium M68 VariLock Extension – 15-20 mm","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eVariable extension from 15mm to 20mm\u003c\/li\u003e\n\u003cli\u003eM68x1 thread standard\u003c\/li\u003e\n\u003cli\u003eFeatures M68 dovetail and receptor\u003c\/li\u003e\n\u003cli\u003eEnables precise back focus adjustment\u003c\/li\u003e\n\u003cli\u003eAllows for camera rotation without loosening threads\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\u003eM68 VariLock Extension – 15-20 mm\u003c\/h2\u003e\n\u003cp\u003eThe M68 VariLock Extension provides a continuous adjustment range from 15mm to 20mm, replacing an entire set of fixed M68 spacer rings within its range. This component is essential for achieving the exact back focus required by field flatteners and reducers, utilizing an M68 dovetail receptor for a secure, non-flexing connection.\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\u003ePrecise M68 Spacing: Dial in 15mm to 20mm of Back Focus\u003c\/h3\u003e\n\u003cp\u003eAchieving perfect star correction across the field depends on hitting a precise back focus distance, often to within a fraction of a millimeter. The M68 VariLock allows you to dial in any spacing between 15mm and 20mm, providing the fine control that fixed-length spacers cannot. This eliminates the trial-and-error of stacking shims and ensures your optical corrector performs exactly as designed.\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 Rotational Framing with the M68 Dovetail\u003c\/h3\u003e\n\u003cp\u003eBeyond spacing, the M68 VariLock integrates a dovetail and receptor system for robust connections and rotational adjustment. Once your imaging train is threaded on, you can loosen the lock, rotate your camera to frame your target perfectly, and re-tighten without losing optical alignment or introducing tilt. This is a significant advantage over standard threaded extensions, which can loosen or bind when trying to adjust camera orientation.\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 M68 VariLock 15-20mm Extension?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe M68 VariLock is designed for fine-tuning the back focus distance in an M68-threaded imaging train. It is crucial when using field flatteners or focal reducers that require a very specific distance to the sensor for optimal performance, allowing you to achieve any spacing between \u003cstrong\u003e15mm and 20mm\u003c\/strong\u003e.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the M68 VariLock's dovetail system improve on standard threads?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe M68 dovetail and receptor provide two key benefits. First, it creates a secure, zero-tilt mechanical lock that prevents flexure. Second, it allows you to rotate your camera for precise framing without unthreading any components, which maintains optical alignment and prevents the connection from loosening accidentally.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the M68 VariLock to set a back focus of 17.5mm for my reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, absolutely. The M68 VariLock's continuous 15mm to 20mm adjustment range covers 17.5mm perfectly. You can set it to that exact distance, lock it down, and be confident your spacing is correct without needing to stack multiple fixed-length spacers.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the M68 VariLock compatible with accessories from other brands?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe M68 VariLock uses the standard M68x1 thread pitch. It is designed to integrate with other components that use this common large-format thread, making it a versatile tool for building robust imaging trains with parts from various manufacturers.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I use the M68 VariLock to frame a target like the Andromeda Galaxy (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAfter achieving focus, you can slightly loosen the VariLock's locking mechanism. This will allow you to rotate your entire camera and filter wheel assembly smoothly. You can then orient your camera sensor to perfectly frame M31's elongated disc and then re-tighten the lock, all without affecting focus or optical alignment.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the M68 VariLock introduce any flexure into my imaging train?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. The M68 dovetail and receptor system is specifically engineered to provide a rigid, secure connection that resists flexure, even with heavy cameras or filter wheels. This is a significant improvement over simple friction-fit or set-screw extension tubes.\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\u003eType\u003c\/td\u003e\n\u003ctd\u003eVariable Locking Extension Tube\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAdjustment Range\u003c\/td\u003e\n\u003ctd\u003e15 mm - 20 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eThread Standard\u003c\/td\u003e\n\u003ctd\u003eM68 x 1 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eConnection System\u003c\/td\u003e\n\u003ctd\u003eM68 Dovetail and Receptor\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNet weight (kg)\u003c\/td\u003e\n\u003ctd\u003e0.06\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInner Diameter \/ Clear Aperture (mm)\u003c\/td\u003e\n\u003ctd\u003e65 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOuter Diameter\u003c\/td\u003e\n\u003ctd\u003e82.1 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType of Adapter\u003c\/td\u003e\n\u003ctd\u003eExtension, Variable Focusing\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\u003eM68 x 1\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\"\u003eM68 VariLock Extension (15-20 mm)\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\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Baader_Planetarium_PushFix_Adapter_Applications_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 PushFix Adapter Applications 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":52913174151453,"sku":"BAA-2458211","price":212.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/BaaderPlanetarium-M68-VariLock-Extension-15-20-mm-1_baa438ac-d79e-4fb8-b42c-581ee6088b37.jpg?v=1789087178","url":"https:\/\/davidastro.com\/products\/baader-planetarium-m68-varilock-extension-15-20-mm","provider":"David Astro","version":"1.0","type":"link"}