{"product_id":"celestron-rasa-6-ota","title":"Celestron RASA 6\" OTA","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e152mm (5.98\") Rowe-Ackermann Schmidt Astrograph\u003c\/li\u003e\n\u003cli\u003eUltra-fast f\/2.2 focal ratio for extremely short exposures\u003c\/li\u003e\n\u003cli\u003e335mm focal length ideal for wide-field imaging\u003c\/li\u003e\n\u003cli\u003eCovers a 22mm useable field with minimal performance loss\u003c\/li\u003e\n\u003cli\u003eLightweight 8.4 lb optical tube for portability\u003c\/li\u003e\n\u003cli\u003eIntegrated filter drawer for 2\" and 1.25\" filters\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\u003eCelestron 6” Rowe-Ackermann Schmidt Astrograph (RASA 6)\u003c\/h2\u003e\n\u003cp\u003eThe Celestron 6” Rowe-Ackermann Schmidt Astrograph (RASA 6) combines a 152mm aperture with an incredibly fast f\/2.2 optical system to dramatically reduce exposure times for deep-sky imaging. Its 335mm focal length provides expansive views, illuminating a useable field of 22mm with spot sizes less than 1.5 μm RMS. Weighing just 8.4 lbs, this compact astrograph delivers professional-grade, flat-field images without requiring a massive equatorial mount.\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 152mm f\/2.2 RASA Optical System\u003c\/h3\u003e\n\u003cp\u003eAt the heart of the RASA 6 is a patented optical design engineered for one purpose: capturing stunning astroimages with unparalleled speed. The f\/2.2 focal ratio gathers light 472x faster than the human eye, allowing you to capture faint details in galaxies and nebulae with sub-exposures that are minutes, not hours, long. The system uses a Schmidt corrector, primary mirror, and a 3-element lens group with StarBright XLT coatings to deliver sharp, coma-free stars across its 16mm optimized image circle.\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 Filter Drawer and 12V Cooling System\u003c\/h3\u003e\n\u003cp\u003eThe RASA 6 is built for the modern imager with features that streamline your workflow. An integrated filter drawer accepts both 2\" and 1.25\" filters, allowing you to easily switch between broadband and narrowband targets without disassembling your camera setup. A 12V DC MagLev fan actively cools the optics to ambient temperature, minimizing thermal noise and ensuring your images are as clean as possible.\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\u003eAn 8.4 lb Portable Astrograph with a CG-5 Dovetail\u003c\/h3\u003e\n\u003cp\u003eDesigned for both backyard and dark-site imaging, the RASA 6 is exceptionally portable. The aluminum optical tube is just 500.5mm long and weighs only 8.4 lbs, making it compatible with a wide range of mid-sized equatorial mounts. It attaches securely via a standard CG-5 dovetail bar, and the included M42 T-thread adapter provides a standard 17.5mm back focus distance for most modern CMOS and CCD astronomy cameras.\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\u003eShort Exposures and a 22mm Useable Field\u003c\/h3\u003e\n\u003cp\u003eThe RASA 6's speed fundamentally changes the imaging experience, enabling a near-real-time view of the deep sky when paired with sensitive cameras and live-stacking software. The optical design provides a 22mm useable field, corresponding to a 3.76° swath of the sky—wide enough to frame large targets like the North America Nebula (NGC 7000). The trade-off for this speed is a significant 46% central obstruction, which reduces contrast on high-resolution planetary targets but is ideal for deep-sky objects where light-gathering is paramount.\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\u003eRASA 6 vs. Slower Refractors: The f\/2.2 Advantage\u003c\/h3\u003e\n\u003cp\u003eCompared to a comparably priced apochromatic refractor, the RASA 6 offers a distinct set of advantages for deep-sky imaging. While a refractor may offer higher contrast for visual use, the RASA 6's f\/2.2 focal ratio is drastically faster than the typical f\/6 or f\/7 of a refractor.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eExposure Speed:\u003c\/strong\u003e An f\/2.2 system captures an image approximately 8-10 times faster than an f\/7 system, meaning a 30-second RASA exposure is equivalent to a 4-5 minute exposure on a typical refractor.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTracking Demands:\u003c\/strong\u003e Shorter exposures significantly reduce the demands on your mount's tracking accuracy, often eliminating the need for an autoguider and simplifying your entire setup.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eResolution:\u003c\/strong\u003e With a Dawes' limit of 0.76 arc seconds, the RASA 6 out-resolves many smaller refractors, revealing finer details in distant galaxies and planetary nebulae.\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 kind of camera is best for the Celestron RASA 6?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe RASA 6 is designed for modern CMOS or CCD astronomy cameras with an M42 T-thread. The system has a fixed \u003cstrong\u003e17.5mm back focus\u003c\/strong\u003e, so you will need to ensure your camera's sensor is at this distance. Small, cylindrical-body cameras are ideal to minimize obstruction of the light path.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use my existing 1.25\" and 2\" filters with the RASA 6?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The RASA 6 includes an integrated filter drawer that holds standard 2\" mounted filters. It also comes with a 1.25\" filter adapter, giving you complete flexibility to use any of your existing astronomy filters for light pollution, narrowband, or LRGB imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow wide of a field can I capture with the RASA 6 on a target like the Andromeda Galaxy (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe RASA 6 provides a useable field of view of 3.76 degrees. Since the Andromeda Galaxy (M31) is approximately 3 degrees long, this astrograph is perfectly suited to frame the entire galaxy, including its faint outer arms and satellite galaxies, in a single shot.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy is the f\/2.2 focal ratio on the RASA 6 so important?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ultra-fast f\/2.2 focal ratio is the key feature of the RASA 6. It allows the optics to collect a huge amount of light in a very short time. This means you can achieve deep, detailed images with much shorter sub-exposures, which simplifies tracking and reduces the chances of satellites or wind ruining your shot.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the RASA 6 work with my existing equatorial mount?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith an optical tube weight of only \u003cstrong\u003e8.4 lbs (3.8 kg)\u003c\/strong\u003e, the RASA 6 is compatible with a wide range of entry-level to intermediate equatorial mounts. It includes a standard CG-5 (Vixen-style) dovetail bar for easy attachment.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the RASA 6 suitable for imaging a bright star cluster like the Pleiades (M45)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. The RASA 6's flat-field optical design ensures that stars remain sharp and point-like across the entire 22mm useable field. Its small spot size of less than 1.5 μm RMS and StarBright XLT coatings will produce crisp stars with excellent color and reveal the faint nebulosity surrounding the Pleiades (M45).\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\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eRowe-Ackermann Schmidt Astrograph\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAperture\u003c\/td\u003e\n\u003ctd\u003e152mm (5.98\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e335mm (13.18\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/2.2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eImage Circle\u003c\/td\u003e\n\u003ctd\u003e16mm (0.63\") Ø, 2.74°\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUseable Field\u003c\/td\u003e\n\u003ctd\u003e22mm (0.86\") Ø, 3.76°\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpot Size\u003c\/td\u003e\n\u003ctd\u003e\u0026lt; 1.5 μm RMS across image circle\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResolution (Rayleigh)\u003c\/td\u003e\n\u003ctd\u003e0.91 arc seconds\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResolution (Dawes)\u003c\/td\u003e\n\u003ctd\u003e0.76 arc seconds\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLight Gathering Power\u003c\/td\u003e\n\u003ctd\u003e472x (Compared to human eye)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCentral Obstruction Diameter\u003c\/td\u003e\n\u003ctd\u003e77mm (3.03\") (46% of aperture)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWavelength Range\u003c\/td\u003e\n\u003ctd\u003e400 - 700 nm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOff-axis Illumination\u003c\/td\u003e\n\u003ctd\u003e91% at 8mm off-axis\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Coatings\u003c\/td\u003e\n\u003ctd\u003eStarBright XLT\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e17.5mm (0.69\") with included camera adapter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCamera Mounting Threads\u003c\/td\u003e\n\u003ctd\u003eM42\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Tube Material\u003c\/td\u003e\n\u003ctd\u003eAluminum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Tube Length\u003c\/td\u003e\n\u003ctd\u003e500.5mm (19.7\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Tube Diameter\u003c\/td\u003e\n\u003ctd\u003e177.8mm (7\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Tube Weight\u003c\/td\u003e\n\u003ctd\u003e8.4 lbs (3.8 kg)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDovetail\u003c\/td\u003e\n\u003ctd\u003eCG-5 Dovetail Bar\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003eStandard Schmidt-Cassegrain focuser\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCooling Fan\u003c\/td\u003e\n\u003ctd\u003e12V DC, MagLev\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Support\u003c\/td\u003e\n\u003ctd\u003eIntegrated drawer for 2\" and 1.25\" filters\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\u003cimg class=\"DAV-img-box\" alt=\"Celestron 6” RASA Optical Tube Assembly\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/celestron-6-rowe-ackermann-schmidt-astrograph-rasa-6-optical-tube-assembly-cg-5-dovetail-1.jpg?v=1795400516\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003e6\" Rowe-Ackermann Schmidt Astrograph OTA\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\u003cimg class=\"DAV-img-box\" alt=\"M42 Camera Adapter for RASA 6\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/celestron-rasa-m42-adapter.jpg?v=1795400892\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eM42 Camera Adapter\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\u003cimg class=\"DAV-img-box\" alt=\"Filter Drawer for RASA 6\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/celestron-rasa-6-filter-drawer.jpg?v=1795400892\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eFilter Drawer with 2\" Clear Filter\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\u003cimg class=\"DAV-img-box\" alt=\"Fan Battery Pack for RASA 6\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/celestron-rasa-fan-battery-pack.jpg?v=1795400892\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eFan Battery Pack\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\/Celestron-RASA-Optics-Whitepaper.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 RASA Whitepaper\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.celestron.com\/pages\/drivers-and-software\" 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 Celestron 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\u003ca href=\"https:\/\/davidastro.com\/pages\/celestron-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eCelestron 2-Year Limited Warranty\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Celestron","offers":[{"title":"Default Title","offer_id":49833921118493,"sku":"CEL-91071","price":1699.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Celestron-RASA-6-OTA-1.jpg?v=1743089875","url":"https:\/\/davidastro.com\/fr-us\/products\/celestron-rasa-6-ota","provider":"David Astro","version":"1.0","type":"link"}