{"product_id":"lunt-solar-1-25-r-p-focuser-single-speed","title":"Lunt Solar 1.25\" R\u0026P Focuser - Single Speed","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eCompatible with LS40THa and LS50THa\u003c\/li\u003e\n\u003cli\u003eFocuser Type: Rack \u0026amp; Pinion\u003c\/li\u003e\n\u003cli\u003eFocuser Ratio: Dual Speed 10:1\u003c\/li\u003e\n\u003cli\u003eBarrel Size: 1.25\"\u003c\/li\u003e\n\u003cli\u003eConnection: Non-Marring Brass Compression Ring\u003c\/li\u003e\n\u003cli\u003eTension: Adjustable with Lock Screw\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\u003eFind the Sun's Sharpest Edge with this Lunt R\u0026amp;P Focuser\u003c\/h2\u003e\n\u003cp\u003eThis Lunt Solar 1.25\" R\u0026amp;P Focuser with dual-speed control is a direct upgrade for achieving the critical focus needed for high-contrast solar observation. Engineered for stability and precision, it replaces less exact helical focusers, giving you the mechanical advantage required to resolve delicate prominences and intricate surface granulation. It provides a solid, repeatable foundation for both visual work and lightweight imaging setups.\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\u003eThe Stability of a Rack and Pinion Drive\u003c\/h3\u003e\n\u003cp\u003eAt the core of this focuser is a robust rack and pinion gear system. Unlike simpler Crayford or helical designs, this geared mechanism provides a positive, slip-free connection between the knob and the drawtube. This is essential for solar observers, as it easily handles the weight of solar-specific eyepieces or a small imaging camera without drifting, ensuring your target remains sharp as you observe.\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\u003eIsolating Detail with 10:1 Fine Focus Control\u003c\/h3\u003e\n\u003cp\u003eThe most critical feature for any solar observer is the ability to make minute focus adjustments. The dual-speed mechanism provides a 10:1 reduction, meaning one full turn of the fine focus knob moves the drawtube one-tenth the distance of the coarse knob. This level of control is not a luxury; it is the key to seeing the faint, hair-like structure in a prominence or the subtle texture of a plage against the chromosphere. It allows you to precisely snap the image into focus where the maximum contrast is achieved.\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 Connections with a Non-Marring Compression Ring\u003c\/h3\u003e\n\u003cp\u003eTo hold your valuable eyepieces and cameras, the focuser uses a brass compression ring instead of a simple thumbscrew. When you tighten the knob, the soft metal ring squeezes evenly around the accessory barrel. This provides a more secure, centered alignment in the optical path and completely avoids the scratches and gouges that set screws inflict on your equipment.\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\u003eHolding Position with Adjustable Tension and Lock\u003c\/h3\u003e\n\u003cp\u003eA dedicated tension screw allows you to customize the focuser's drawtube resistance to match the weight of your accessory. Heavier loads can be supported by increasing tension, preventing focus sag when the telescope is aimed high. For imaging, the ability to completely lock the focus position is invaluable, preventing any accidental shifts during an exposure sequence.\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\u003eThe Solar Observer's Experience with a Precision Focuser\u003c\/h3\u003e\n\u003cp\u003eImagine you are tuned to a large, looping prominence on the solar limb with a Lunt LS50THa. With the coarse knob, you bring the limb into general focus. You then switch to the 10:1 fine focus knob, and with a tiny, deliberate turn, the fuzzy, bright mass resolves into a delicate tapestry of individual plasma filaments. The focuser holds this perfect point of sharpness without drift, allowing your eye to relax and take in the view as the structure slowly evolves.\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\u003eA Note on System Compatibility\u003c\/h3\u003e\n\u003cp\u003eThis 1.25\" focuser is an ideal match for visual solar work and setups using small, lightweight solar imagers. Its primary trade-off is its smaller barrel size. For observers planning to use heavy camera and filter wheel combinations, a larger 2-inch focuser would provide greater stability and avoid potential vignetting, though at a significant increase in size and cost.\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 Lunt Focuser Upgrade\u003c\/h3\u003e\n\u003cp\u003eLunt employs several focuser designs across their telescope line, each suited to a specific purpose. Understanding the differences helps you know if this R\u0026amp;P model is the right upgrade for your system.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003evs. Lunt Helical Focuser:\u003c\/strong\u003e The standard helical focuser found on some entry-level Lunt scopes is compact but can be difficult to adjust with precision. This Rack \u0026amp; Pinion model is a significant upgrade in smoothness, load-bearing capacity, and fine-focus control, making it easier to achieve and hold optimal sharpness.\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\"\u003eIs this R\u0026amp;P focuser better than the standard Lunt helical focuser?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, for most users it is a substantial upgrade. The dual-speed rack and pinion mechanism provides much finer focus control, is easier to adjust without shaking the telescope, and can better support the weight of a camera without slipping.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill this focuser fit my non-Lunt telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis focuser is designed specifically for the tube assemblies of Lunt solar telescopes like the LS40THa and LS50THa and LS60MT. It is not intended as a universal-fit upgrade for other brands.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat's the main benefit of the 10:1 fine focus for solar?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eSolar details exist at a very fine scale. The 10:1 fine focus knob allows you to make extremely small adjustments to achieve the sharpest possible view of solar prominences, filaments, and surface granulation, which can be impossible with a single-speed focuser.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use 2-inch eyepieces with this focuser?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this is a 1.25-inch format focuser. It only accepts eyepieces and accessories that have a 1.25\" barrel.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy use a rack and pinion focuser instead of a Crayford?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA rack and pinion system provides a positive, geared connection that does not slip, making it very reliable for holding heavier loads. While modern Crayford focusers are very smooth, the geared design of an R\u0026amp;P ensures it will not lose its position, even with a camera attached.\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\u003eFocuser Type\u003c\/td\u003e\n\u003ctd\u003eRack \u0026amp; Pinion (R\u0026amp;P)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocusing Ratio\u003c\/td\u003e\n\u003ctd\u003eDual Speed, 10:1 Reduction Fine Focus\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAccessory Size\u003c\/td\u003e\n\u003ctd\u003e1.25\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAccessory Connection\u003c\/td\u003e\n\u003ctd\u003eNon-Marring Brass Compression Ring\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTension Control\u003c\/td\u003e\n\u003ctd\u003eAdjustable via Thumbscrew\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocus Lock\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Compatibility\u003c\/td\u003e\n\u003ctd\u003eLunt Solar Systems Telescopes (e.g., LS50THa, LS60MT)\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\" Dual Speed R\u0026amp;P Focuser Assembly\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\"\u003e1.25\" Dust Cap\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\u003ca href=\"https:\/\/davidastro.com\/pages\/lunt-solar-system-warranty\" rel=\"noopener\" target=\"_blank\"\u003eLunt Solar Systems 5-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Lunt Solar Systems","offers":[{"title":"Default Title","offer_id":50904177672477,"sku":"LSS-001-147","price":169.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Lunt-125inch-RP-Focuser-Single-Speed-1.jpg?v=1769885106","url":"https:\/\/davidastro.com\/fr-us\/products\/lunt-solar-1-25-r-p-focuser-single-speed","provider":"David Astro","version":"1.0","type":"link"}