{"product_id":"svbony-sv161-double-helical-micro-focuser-125in","title":"SVBONY SV161 Double Helical Micro Focuser - 1.25\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003ePrecise 0.05mm adjustment accuracy for fine focusing\u003c\/li\u003e\n\u003cli\u003e10mm of draw tube travel\u003c\/li\u003e\n\u003cli\u003eNon-rotating mechanism keeps camera orientation fixed\u003c\/li\u003e\n\u003cli\u003eStandard M42x0.75 T2-threads for universal compatibility\u003c\/li\u003e\n\u003cli\u003eAccepts 1.25\" eyepieces and accessories\u003c\/li\u003e\n\u003cli\u003eLightweight at only 100g\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\u003eSVBONY SV161 1.25-inch Double Helical Micro Focuser\u003c\/h2\u003e\n\u003cp\u003eThe SVBONY SV161 1.25-inch Double Helical Micro Focuser provides critical focus control with a 0.05mm adjustment accuracy over 10mm of travel. Its dual M42x0.75 threads ensure broad compatibility with guide scopes and cameras, while the entire assembly adds only 100g to your imaging train and extends from a minimum height of 43mm to a maximum of 53mm.\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\u003e0.05mm Adjustment Accuracy: Fine-Tune Your Guide Star Focus\u003c\/h3\u003e\n\u003cp\u003eAchieving tight, round stars in a long-exposure image depends on precise guiding, which starts with a perfectly focused guide camera. The SV161 helical focuser offers a 0.05mm adjustment accuracy, allowing you to make minute changes that bring faint guide stars into sharp relief. This level of control eliminates the slop and backlash common in basic guide scope focusers, ensuring your autoguiding software has a crisp, high-signal star to lock onto.\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\u003eNon-Rotating Stability Across 10mm of Travel\u003c\/h3\u003e\n\u003cp\u003eA common frustration with simple helical focusers is the rotation of the attached camera or eyepiece during adjustment. The SV161's double helical design provides 10mm of smooth focus travel without rotating your camera. This is essential for maintaining your guide star selection in software and keeping your camera's orientation fixed, simplifying setup and calibration. Once focus is achieved, a locking screw holds the position firmly, preventing any drift during an imaging session.\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\u003eUniversal M42x0.75 Threading and 1.25\" Compatibility\u003c\/h3\u003e\n\u003cp\u003eEngineered for versatility, the SV161 features a female M42x0.75 (T2) thread on the telescope side and a male M42x0.75 thread on the camera side. This industry-standard threading allows it to integrate seamlessly into most guide scope and small camera setups without extra adapters. The focuser's 1.25\" inner diameter also allows you to use it visually with 1.25\" eyepieces, making it a useful tool for accurately setting the focus of a finder or guide scope before attaching a camera.\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 advantage of the SVBONY SV161 over a guide scope's built-in focuser?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe SVBONY SV161 provides significantly finer control with its \u003cstrong\u003e0.05mm adjustment accuracy\u003c\/strong\u003e. Most built-in focusers on guide scopes are simple sliding tubes or have coarse threads, making precise focus difficult. The SV161's double helical mechanism eliminates this issue, allowing for the critical sharpness needed for accurate autoguiding.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the SVBONY SV161 rotate my guide camera when I adjust focus?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, it will not. The SV161 uses a non-rotating double helical design. This means your camera or eyepiece remains in a fixed orientation as you move through the \u003cstrong\u003e10mm of focus travel\u003c\/strong\u003e, which is critical for maintaining your guide star selection within your software.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I attach the SVBONY SV161 to my equipment?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe SV161 uses standard \u003cstrong\u003eM42x0.75 T2-threads\u003c\/strong\u003e. The bottom female thread attaches to your guide scope or off-axis guider, and the top male thread connects to your T-threaded guide camera or a 1.25\" eyepiece holder. The 1.25\" inner diameter also allows direct insertion of 1.25\" nosepieces.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the 10mm travel of the SVBONY SV161 enough for most guide cameras?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eFor most setups where the SV161 is used for fine-tuning, the \u003cstrong\u003e10mm of travel\u003c\/strong\u003e is sufficient. It is designed to provide precise final adjustments after coarse focus is set by sliding the camera in its holder. For setups requiring a very large focus shift, you may need additional extension tubes.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the SVBONY SV161 to get a sharp focus on a guide star near the Pinwheel Galaxy (M101) with my 50mm guide scope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. This is an ideal use case. Finding a suitable guide star near a dim target like M101 often means using a fainter star. The SV161's \u003cstrong\u003e0.05mm adjustment accuracy\u003c\/strong\u003e will allow you to dial in the focus perfectly, maximizing the signal-to-noise ratio on that faint star and enabling more accurate guiding for your main exposure.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the SVBONY SV161 work with my off-axis guider (OAG)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the SV161 is an excellent tool for focusing an OAG. The limited and often tricky focusing mechanisms on OAGs can be replaced or supplemented by the SV161. Its M42x0.75 threads and non-rotating design make it easy to achieve and lock critical focus on the guide prism without disturbing the main camera.\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\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eSVBONY\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInner Diameter\u003c\/td\u003e\n\u003ctd\u003e1.25\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDraw Tube Travel\u003c\/td\u003e\n\u003ctd\u003e10mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAdjustment Accuracy\u003c\/td\u003e\n\u003ctd\u003e0.05mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTop Male Thread\u003c\/td\u003e\n\u003ctd\u003eM42x0.75\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBottom Female Thread\u003c\/td\u003e\n\u003ctd\u003eM42x0.75\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMinimum Height\u003c\/td\u003e\n\u003ctd\u003e43mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum Height\u003c\/td\u003e\n\u003ctd\u003e53mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNet Weight\u003c\/td\u003e\n\u003ctd\u003e100g \/ 3.53oz\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\"\u003e1.25\" Double Helical Focuser w\/ Female T2-Thread\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eM3 Screw\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 3\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/svbony-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eSVBONY 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"SVBONY","offers":[{"title":"Default Title","offer_id":52861262823709,"sku":"SV-F9173B","price":40.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/SVBONY-SV161-1-25inch-Double-Helical-Micro-Focuser-Metal-Black-for-Telescope-1_b1bd5007-1496-4a02-bcbc-0eebbeaedb77.jpg?v=1788660711","url":"https:\/\/davidastro.com\/fr\/products\/svbony-sv161-double-helical-micro-focuser-125in","provider":"David Astro","version":"1.0","type":"link"}