{"title":"SharpStar SCA Cassegrain Astrographs","description":"\u003cp\u003eSharpStar SCA astrographs are Cassegrain telescopes with built-in correction, designed to give a flat, well-corrected field for imaging at longer focal lengths in a short tube. The SCA260 V2 is a 260mm f\/5 Super Cassegrain, and the SCA310 is a 310mm f\/3.8 aspherical Cassegrain that pairs large aperture with a fast focal ratio.\u003c\/p\u003e\u003cp\u003eThey suit galaxies, planetary nebulae and smaller deep-sky targets, and call for a solid mount with good guiding.\u003c\/p\u003e","products":[{"product_id":"sharpstar-sca260-v2-260mm-f-5-super-cassegrain-astrograph","title":"SharpStar SCA260 V2 260mm f\/5 Super Cassegrain Astrograph","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e260mm (10.2\") Aperture Aspherical Primary Mirror\u003c\/li\u003e\n\u003cli\u003e1300mm Focal Length at a fast f\/5 Focal Ratio\u003c\/li\u003e\n\u003cli\u003eMassive 80mm Corrected Image Circle for Large Format Sensors\u003c\/li\u003e\n\u003cli\u003eLightweight Carbon Fiber Tube Weighing 14.5kg\u003c\/li\u003e\n\u003cli\u003e3.35\" Rack and Pinion Focuser with 360° Rotator\u003c\/li\u003e\n\u003cli\u003e70mm Back Focus from the M48 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\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\u003eSharpStar SCA260 V2 260mm f\/5 Super Cassegrain Astrograph\u003c\/h2\u003e\n\u003cp\u003eThe SharpStar SCA260 V2 is an imaging instrument designed for large-format sensors, combining a 260mm aspherical primary mirror and a fast f\/5 optical system to produce a massive 80mm corrected image circle. With a native focal length of 1300mm, it achieves a theoretical resolution of 0.46 arc-seconds, capable of capturing fine detail in distant galaxies. The entire optical tube assembly weighs only 14.5kg, making it manageable for a wide range of equatorial mounts.\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\u003e260mm f\/5 Optics with an 80mm Corrected Image Circle\u003c\/h3\u003e\n\u003cp\u003eAt the heart of the SCA260 V2 is a 260mm aspherical primary mirror made from PZ33, a Pyrex-like glass with excellent thermal stability. Paired with a three-element air-spaced corrector, this f\/5 system illuminates an enormous 80mm image circle, free of significant vignette or distortion. This makes the SCA260 V2 fully compatible with the largest professional CMOS and CCD sensors available, including those with diagonals exceeding 60mm.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAspherical Primary Mirror:\u003c\/strong\u003e Provides superior correction compared to standard spherical mirrors, critical for achieving sharp focus across the large imaging field.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEnhanced Aluminum Coatings:\u003c\/strong\u003e Both the primary and 120mm minor axis secondary mirror feature coatings that ensure high reflectivity for brighter images and reduced exposure times.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFull-Frame and Beyond:\u003c\/strong\u003e The 80mm image circle provides ample coverage for full-frame (43mm diagonal) sensors and larger medium-format chips without requiring a separate reducer or flattener.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003e14.5kg Carbon Fiber Tube and Simplified Collimation\u003c\/h3\u003e\n\u003cp\u003eThe optical tube is constructed from carbon fiber, which provides a high stiffness-to-weight ratio and minimizes thermal expansion and contraction during long imaging sessions. This ensures focus remains stable as ambient temperatures change overnight. The total tube weight of 14.5kg places it within the payload capacity of many mid-to-high-end equatorial mounts.\u003c\/p\u003e\n\u003cp\u003eSharpStar has engineered the collimation mechanics for field accessibility. Unlike traditional Cassegrain designs that require complex adjustments, the SCA260 V2's optical alignment is primarily controlled by adjusting the secondary mirror's pull rod, simplifying the process of achieving perfect star shapes.\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\u003e3.35\" Focuser with 70mm of Back Focus\u003c\/h3\u003e\n\u003cp\u003eThe SCA260 V2 is equipped with a heavy-duty 3.35\" rack and pinion focuser designed to carry professional imaging trains without flexure or slippage. The rear of the focuser includes a 360° rotator for effortless camera framing and a built-in 2-inch filter holder. It provides a generous 70mm of back focus distance from the M48x0.75 threaded connection, accommodating filter wheels, off-axis guiders, and other accessories.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMultiple Connection Threads:\u003c\/strong\u003e The focuser terminates in a versatile adapter system with M68x1, M54x0.75, and M48x0.75 threads to connect to nearly any camera or accessory.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e360° Rotator:\u003c\/strong\u003e Allows you to frame your target precisely without loosening the camera or introducing tilt into the optical train.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCNC Handlebar:\u003c\/strong\u003e The integrated handle is not just for carrying; it also serves as a mounting platform for guide scopes or other accessories, further streamlining your setup.\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\"\u003eWhat imaging sensors can the SCA260 V2's 80mm image circle cover?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e80mm image circle\u003c\/strong\u003e of the SharpStar SCA260 V2 is large enough to fully illuminate professional-grade sensors, including full-frame (e.g., IMX455, 43mm diagonal) and medium-format sensors (e.g., IMX461, 55mm diagonal) with minimal vignetting. This makes it an ideal choice for creating large-scale mosaics and imaging wide fields of view.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the f\/5 focal ratio of the SCA260 V2 benefit deep-sky imaging?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAn \u003cstrong\u003ef\/5 focal ratio\u003c\/strong\u003e is considered fast for an astrograph of this aperture. It allows you to collect a significant amount of light in a shorter period compared to slower f\/8 or f\/10 systems. This reduces individual sub-exposure times, which can lessen the impact of tracking errors and changing atmospheric conditions.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the advantage of the PZ33 primary mirror material in the SCA260 V2?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003e\u003cstrong\u003ePZ33\u003c\/strong\u003e is a borosilicate glass with a very low coefficient of thermal expansion, similar to Pyrex. This means the mirror's shape remains stable as the temperature drops throughout the night, preventing the focal point from shifting. This thermal stability is critical for maintaining sharp focus during long-exposure astrophotography.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I collimate the SharpStar SCA260 V2?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe SCA260 V2 features a simplified collimation system. The primary adjustment is made to the \u003cstrong\u003espherical secondary mirror\u003c\/strong\u003e using an integrated pull rod mechanism. This is generally more straightforward than adjusting both the primary and secondary mirrors on traditional Cassegrain telescopes.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I image the entire Veil Nebula (NGC 6960) with the SCA260 V2 and a full-frame camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The Veil Nebula complex spans approximately 3 degrees of the sky. With the SCA260 V2's \u003cstrong\u003e1300mm focal length\u003c\/strong\u003e and a full-frame sensor (like a Sony a7 series or ZWO ASI6200), you can capture large sections of the nebula in a single frame and create a high-resolution mosaic of the entire complex in just a few panes.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat class of mount is required for the 14.5kg tube weight of the SCA260 V2?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eGiven the \u003cstrong\u003e14.5kg tube weight\u003c\/strong\u003e, plus the additional weight of a camera, guide scope, and other accessories, a mount with a payload capacity of at least 25-30kg (55-66 lbs) is recommended for stable, long-exposure imaging. Mounts in the Sky-Watcher EQ8, iOptron CEM70\/CEM120, or equivalent class are appropriate.\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\u003eAperture\u003c\/td\u003e\n\u003ctd\u003e260mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e1300mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrected Image Circle\u003c\/td\u003e\n\u003ctd\u003e80mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Mirror Type\u003c\/td\u003e\n\u003ctd\u003eAspherical Reflector\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Mirror Material\u003c\/td\u003e\n\u003ctd\u003ePZ33 (Pyrex-like)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Mirror Type\u003c\/td\u003e\n\u003ctd\u003eSpherical Reflector\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Mirror Minor Axis\u003c\/td\u003e\n\u003ctd\u003e120mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrector\u003c\/td\u003e\n\u003ctd\u003eThree-element air-spaced lens structure\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e3.35\" Rack \u0026amp; Pinion\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus (from M48 thread)\u003c\/td\u003e\n\u003ctd\u003e70mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Material\u003c\/td\u003e\n\u003ctd\u003eCarbon Fiber\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Diameter\u003c\/td\u003e\n\u003ctd\u003e304mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Weight\u003c\/td\u003e\n\u003ctd\u003e14.5kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResolution\u003c\/td\u003e\n\u003ctd\u003e0.46 arc-seconds\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLimiting Visual Magnitude\u003c\/td\u003e\n\u003ctd\u003e13.8\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\"\u003eSharpStar SCA260 V2 OTA\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:\/\/www.sharpstar-optics.com\/download_list_1\/7.html\" 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\"\u003eDownload Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.sharpstar-optics.com\/download_list_1\/7.html\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e \n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software\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\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"SharpStar Optics","offers":[{"title":"Default Title","offer_id":44967740866845,"sku":"SSO-SCA260V2","price":6461.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/SharpStar-SCA260-1__12455.1608934024.1280.1280.jpg?v=1684345748"},{"product_id":"sharpstar-sca310","title":"Sharpstar SCA310 f\/3.8 Aspherical Cassegrain Astrograph","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e310mm Aperture Aspherical Primary Mirror\u003c\/li\u003e\n\u003cli\u003e1178mm Focal Length at a Fast f\/3.8\u003c\/li\u003e\n\u003cli\u003e55mm Corrected Image Circle for Medium Format Sensors\u003c\/li\u003e\n\u003cli\u003eTriplet Corrector with one ED Glass Element\u003c\/li\u003e\n\u003cli\u003eLightweight Carbon Fiber Tube Construction\u003c\/li\u003e\n\u003cli\u003e3.5-inch Rack-and-Pinion Focuser with 360° Rotator\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\u003eSharpstar SCA310 f\/3.8 Aspherical Cassegrain Astrograph\u003c\/h2\u003e\n\u003cp\u003eThe Sharpstar SCA310 combines a massive 310mm aspherical primary mirror with a fast f\/3.8 focal ratio to deliver exceptional light-gathering power in a compact design. Its integrated triplet corrector produces a flat, coma-free 55mm image circle, fully illuminating medium-format sensors. With a tube length of just 721mm and a total weight of 23.5kg, this astrograph provides the deep-sky imaging capability of a much larger instrument.\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\u003e310mm f\/3.8 Aspherical Optics: A 55mm Corrected Image Circle\u003c\/h3\u003e\n\u003cp\u003eAt the core of the SCA310 is a 310mm aspherical primary mirror, precisely figured to eliminate spherical aberration for sharp, point-like stars. Paired with a thermally stable secondary, this system achieves a 1178mm focal length. A permanently integrated 3-element corrector, featuring one ED glass element, flattens the field and corrects for coma, producing a 55mm image circle capable of covering the largest full-frame and medium-format CMOS sensors with near 100% illumination.\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\u003e721mm Carbon Fiber Tube: Thermal Stability at 23.5kg\u003c\/h3\u003e\n\u003cp\u003eThe SCA310's optical path is housed in a carbon fiber tube, which offers a superior stiffness-to-weight ratio and minimal thermal expansion. This ensures that focus remains stable during temperature drops over a long imaging session. The entire optical tube assembly is only 721mm long, a significant advantage for portability and mount requirements compared to other designs of similar aperture, and weighs a substantial 23.5kg.\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\u003e3.5-inch Focuser: 30mm Travel and 360° Rotation\u003c\/h3\u003e\n\u003cp\u003eTo handle modern heavy imaging trains, the SCA310 is equipped with a 3.5-inch high-rigidity rack-and-pinion focuser. This unit provides 30mm of travel with a 1:10 dual-speed knob for precise adjustments and can support heavy camera and filter wheel combinations without slippage. A 360° rotator allows for easy framing of your target, and the rear is equipped with M68, M54, and M48 adapters for direct connection to your camera. The M48 adapter also includes a built-in thread for 2-inch filters.\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\u003eIntegrated Cooling: 3 Fans for Rapid Thermal Equilibrium\u003c\/h3\u003e\n\u003cp\u003eTo maximize image quality from the start of your session, the SCA310 integrates three cooling fans behind the primary mirror. Activating these fans before you begin imaging rapidly brings the 310mm primary mirror to ambient temperature. This minimizes tube currents and ensures the sharpest possible views, significantly improving efficiency and overall imaging results.\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\u003eSCA310 vs. 12\" Newtonian Astrographs: The Cassegrain Advantage\u003c\/h3\u003e\n\u003cp\u003eWhile a 12\" (approx. 300mm) f\/4 Newtonian offers similar aperture and speed, the SCA310's Cassegrain design provides distinct advantages for the dedicated astrophotographer.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompactness:\u003c\/strong\u003e The SCA310's 721mm tube is over 400mm shorter than a typical 12\" f\/4 Newtonian OTA. This makes it easier to transport, balance, and house in an observatory, and it places less strain on the mount.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIntegrated Correction:\u003c\/strong\u003e The SCA310's corrector is a permanent, optimized part of the optical design. You do not need to purchase or install a separate coma corrector, and the back focus is fixed and simple to work with.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStray Light and Dew:\u003c\/strong\u003e The closed carbon fiber tube offers superior protection against stray light and dew formation compared to the open-truss or single-wall design of most large Newtonians.\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\"\u003eWhat makes the Sharpstar SCA310's f\/3.8 Cassegrain design unique?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe SCA310 uses an \u003cstrong\u003easpherical primary mirror\u003c\/strong\u003e in a Cassegrain configuration. This allows it to achieve a fast f\/3.8 focal ratio and a long 1178mm focal length within a very short 721mm tube. Combined with its integrated triplet corrector, it delivers a large, flat, and coma-free field for serious deep-sky imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the SCA310's integrated corrector handle large sensors?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe 3-element corrector is specifically designed to produce a \u003cstrong\u003e55mm image circle\u003c\/strong\u003e. This is large enough to cover medium-format sensors and provides excellent, pinpoint stars from edge to edge on full-frame sensors without vignetting, making it ideal for large-format cameras.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan the Sharpstar SCA310 fully illuminate a camera like the ZWO ASI2600MC Pro?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, absolutely. The ZWO ASI2600MC Pro has an APS-C sensor with a diagonal of about 28mm. The SCA310's \u003cstrong\u003e55mm image circle\u003c\/strong\u003e will fully illuminate this sensor with plenty of room to spare, ensuring a bright, flat field without any vignetting caused by the optics.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I need to calculate back focus for the Sharpstar SCA310?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. According to Sharpstar, the SCA310's optical structure is optimized so that you do not need to perform additional back focus calculations. The included M68, M54, and M48 adapters are designed to place your sensor at the correct distance, simplifying the imaging process significantly.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the SCA310's 1178mm focal length perform on small targets like the Dumbbell Nebula (M27)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e1178mm focal length\u003c\/strong\u003e is excellent for framing planetary nebulae like M27 or galaxies like the Whirlpool Galaxy (M51). When paired with a camera using small pixels, you can achieve high-resolution sampling to capture fine structural details in these smaller deep-sky objects.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat class of mount is required for the 23.5kg Sharpstar SCA310?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith a gross weight of \u003cstrong\u003e23.5kg (51.8 lbs)\u003c\/strong\u003e before adding a camera, guide scope, and other accessories, the SCA310 requires a high-capacity equatorial mount. You should look for a mount with a stated instrument capacity of at least 70-80 lbs (approx. 32-36 kg) to ensure stable, flexure-free tracking for long-exposure astrophotography.\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\u003eAperture\u003c\/td\u003e\n\u003ctd\u003e310mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e1178mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/3.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResolution\u003c\/td\u003e\n\u003ctd\u003e0.37\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eImage Circle\u003c\/td\u003e\n\u003ctd\u003e55mm (Medium Format)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Mirror Type\u003c\/td\u003e\n\u003ctd\u003eAspherical\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Mirror Diameter\u003c\/td\u003e\n\u003ctd\u003e184mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrector Type\u003c\/td\u003e\n\u003ctd\u003eTriplet design (with one ED glass element)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Material\u003c\/td\u003e\n\u003ctd\u003eCarbon Fiber\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Outer Diameter\u003c\/td\u003e\n\u003ctd\u003e378mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Length\u003c\/td\u003e\n\u003ctd\u003e721mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGross Weight\u003c\/td\u003e\n\u003ctd\u003e23.5kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRear Thread Adapters\u003c\/td\u003e\n\u003ctd\u003eM68, M54, M48 (with M48x0.75 filter thread)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus Range\u003c\/td\u003e\n\u003ctd\u003eSupports 38-66mm\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\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/SharpStar_SCA310_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\"\u003eDownload Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/askar-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eAskar 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"SharpStar Optics","offers":[{"title":"Default Title","offer_id":52851347718429,"sku":"SSO-SCA310","price":11193.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Askar-SCA310-1_df2ed418-69a4-4967-82b4-11f294440cc2.jpg?v=1788401926"}],"url":"https:\/\/davidastro.com\/collections\/sharpstar-sca-cassegrain-astrographs.oembed","provider":"David Astro","version":"1.0","type":"link"}