{"product_id":"primalucelab-pl3600317","title":"PrimaLuceLab 40mm Extension Tube for ESATTO 3\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eAdds 40mm of back focus for ESATTO 3\" focusers\u003c\/li\u003e\n\u003cli\u003eEnables focus with long-travel telescopes like refractors\u003c\/li\u003e\n\u003cli\u003ePrecise dovetail coupling system for rigidity\u003c\/li\u003e\n\u003cli\u003eAllows manual focuser rotation for camera framing\u003c\/li\u003e\n\u003cli\u003eFeatures 3 locking screws set at 120° for a secure, no-tilt connection\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\u003ePrimaLuceLab 40mm Extension Tube for ESATTO 3\"\u003c\/h2\u003e\n\u003cp\u003eThe PrimaLuceLab 40mm Extension Tube solves critical back focus issues when installing the ESATTO 3\" on telescopes with long-travel stock focusers. Its integrated dovetail system, secured by 3 screws set at 120° intervals, also provides manual rotation for precise camera framing.\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\u003eBridge the 40mm Back Focus Gap for ESATTO 3\"\u003c\/h3\u003e\n\u003cp\u003eThe ESATTO 3\" is a micrometric focuser, engineered for high-precision adjustments rather than extensive draw tube travel. When retrofitting it onto telescopes like refractors that often feature long-travel stock focusers, this 40mm extension tube provides the necessary spacing to bring your camera and accessories to the focal plane.\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\u003eFrame Your Target with the 3-Screw, 120° Lock System\u003c\/h3\u003e\n\u003cp\u003eThis is more than a simple spacer. The extension incorporates a precise dovetail coupling system that allows you to manually rotate the entire ESATTO 3\" focuser. By loosening the three locking screws, you can orient your imaging train for optimal composition of celestial objects, then tighten them down for a rigid, flex-free connection. The 120° spacing of the screws ensures the load is distributed evenly, preventing any tilt in the optical path.\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\u003eChoosing Your Extension: 40mm vs. 65mm for ESATTO 3\"\u003c\/h3\u003e\n\u003cp\u003ePrimaLuceLab also offers a 65mm extension for the ESATTO 3\". The correct choice depends entirely on your telescope's specific back focus requirements. The 40mm extension is ideal for setups that need a moderate amount of additional spacing to reach focus. For systems with even longer focal paths, the 65mm version may be required. Always measure your required back focus before selecting an extension.\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\"\u003eWhy do I need this 40mm extension for my ESATTO 3\"?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eMany stock focusers, especially on refractor telescopes, have a long range of travel. The ESATTO 3\" is a high-precision robotic focuser with a shorter, more exact travel range. The \u003cstrong\u003e40mm extension tube\u003c\/strong\u003e compensates for this difference, adding the fixed spacing needed to ensure your camera can reach focus with the ESATTO 3\".\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the rotational adjustment on the 40mm ESATTO 3\" extension work?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe extension features a dovetail mechanism with three locking screws set at 120-degree intervals around its body. To rotate your focuser:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eSlightly loosen the three screws.\u003c\/li\u003e\n\u003cli\u003eManually rotate the connected ESATTO 3\" focuser to your desired orientation.\u003c\/li\u003e\n\u003cli\u003eRe-tighten the three screws to lock it securely in place.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThis allows you to perfectly frame objects like the Andromeda Galaxy (M31) or manage cable routing without disassembling your imaging train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhen should I choose the 40mm ESATTO 3\" extension over the 65mm version?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe choice depends on your specific telescope and imaging train. The \u003cstrong\u003e40mm extension\u003c\/strong\u003e is suitable when you need a moderate amount of extra back focus. If you find your ESATTO 3\" runs out of inward travel and is still far from focus, you likely need a longer extension like the 65mm version. It's best to measure the focus position with your original focuser to determine the required extension length.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill adding the 40mm extension tube introduce flexure to my imaging setup?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. The PrimaLuceLab 40mm extension is designed for rigidity. The precise dovetail coupling and the three-screw locking system create a solid, stable connection between the telescope and the ESATTO 3\" focuser, preventing tilt and flexure even with heavy imaging loads.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the 40mm extension tube with a Ritchey-Chrétien telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile this extension is primarily designed to solve the travel-length issue common with refractors, it can be used on any telescope where the ESATTO 3\" requires exactly 40mm of additional spacing to reach focus. For specific telescopes like large GSO\/Orion\/TPO Ritchey-Chrétiens, PrimaLuceLab makes dedicated adapters (like PL3600236) which may be more suitable as they adapt the thread type as well as providing spacing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I stack multiple 40mm ESATTO 3\" extension tubes?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eStacking extensions is generally not recommended as each connection point is a potential source of tilt or flexure. If you require more than 40mm of spacing, it is mechanically superior to use a single, longer extension, such as the 65mm version for the ESATTO 3\", to ensure maximum rigidity for your imaging train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\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\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/primalucelab-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003ePrimaLuceLab 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"PrimaLuceLab","offers":[{"title":"Default Title","offer_id":52913379148061,"sku":"PLL-PL3600317","price":175.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/PrimaLuceLab-40mm-extension-tube-for-ESATTO-3-1_f84dd50c-fdd2-470f-ae06-bf5a65bdd944.jpg?v=1789090088","url":"https:\/\/davidastro.com\/fr\/products\/primalucelab-pl3600317","provider":"David Astro","version":"1.0","type":"link"}