{"product_id":"orion-optics-uk-ct10-optical-tube-assembly","title":"Orion Optics UK CT10 Optical Tube Assembly","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e250mm (10\") Aperture Newtonian Reflector\u003c\/li\u003e\n\u003cli\u003e1200mm Focal Length\u003c\/li\u003e\n\u003cli\u003ef\/4.8 Focal Ratio\u003c\/li\u003e\n\u003cli\u003eGuaranteed 1\/10 PV Wavefront Optics\u003c\/li\u003e\n\u003cli\u003eCarbon Fibre Sandwich Construction Tube\u003c\/li\u003e\n\u003cli\u003e9-Point CNC Machined Mirror Cell\u003c\/li\u003e\n\u003cli\u003e2\" Focuser with Reduction Gearing\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\u003eOrion Optics UK CT10 Optical Tube Assembly\u003c\/h2\u003e\n\u003cp\u003eThe Orion Optics UK CT10 sets an uncompromising standard for high-resolution imaging, built around a hand-figured 250mm Suprax primary mirror guaranteed to a 1\/10 PV wavefront accuracy. Its fast f\/4.8 focal ratio and 1200mm focal length provide the image scale needed for detailed views of planets and deep-sky targets. Housed in a 1050mm carbon fibre sandwich tube and supported by a 9-point CNC-machined cell, the CT10 delivers optical perfection with the mechanical stability required to achieve it.\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\u003eUltra-Grade 1\/10 PV Optics: The Apex of Newtonian Performance\u003c\/h3\u003e\n\u003cp\u003eThe heart of the CT10 is its 250mm primary mirror, figured to Orion Optics UK's highest \"Ultra\" grade of 1\/10 Peak-to-Valley (PV) wavefront. This level of precision, verified by an included Zygo interferometer report, ensures that the maximum amount of light is focused into a single point, producing images with exceptional contrast and sharpness. Paired with enhanced Hilux coatings, the optical system delivers maximum light transmission for brighter views of faint objects.\u003c\/p\u003e\n\u003cp\u003eCompared to standard \"diffraction-limited\" 1\/4 PV optics, a 1\/10 PV mirror minimizes scattered light and resolves finer details, a critical advantage for separating tight double stars or discerning subtle cloud bands on Jupiter. This isn't an optional upgrade; it's the standard for the CT series, built for observers who demand the highest possible fidelity from their 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\u003eCarbon Fibre Sandwich Tube: 1050mm of Thermal Stability\u003c\/h3\u003e\n\u003cp\u003eTo maintain the precision of its optics, the CT10 employs a carbon fibre sandwich tube with a 300mm diameter. This advanced material has a near-zero coefficient of thermal expansion, meaning the 1200mm focal length remains constant even as ambient temperatures drop during an observing session. This eliminates the need for constant refocusing, a common issue with aluminum or steel tube telescopes, making it ideal for long-exposure astrophotography.\u003c\/p\u003e\n\u003cp\u003eThe 1050mm tube is finished with a gloss exterior and a matte black interior to absorb stray light and maximize image contrast. At a weight of only 11kg, the CT10 OTA is manageable for a wide range of equatorial mounts capable of supporting its payload and length.\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\u003ePrecision Mechanics: A 9-Point Cell and 2\" Geared Focuser\u003c\/h3\u003e\n\u003cp\u003eAn exceptional mirror requires an equally capable support system. The CT10 features a CNC-machined 9-point flotation cell that supports the 250mm primary mirror without introducing any print-through or astigmatism. This ensures the mirror's lab-tested accuracy is realized at the eyepiece. The secondary mirror is held in a rigid, rotatable aluminum holder by a fully adjustable 4-vane stainless steel spider, minimizing diffraction effects.\u003c\/p\u003e\n\u003cp\u003eFor critical focusing, the CT10 is equipped with a 2\" focuser with reduction gearing, allowing for smooth, minute adjustments essential for achieving sharp focus at high magnifications or with an imaging camera. The optical train is completed with a pair of CNC-machined tube rings, providing a secure and stable mounting platform for the 11kg tube assembly.\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 does the 1\/10 PV wavefront accuracy of the CT10 mean for visual observing?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA \u003cstrong\u003e1\/10 PV wavefront\u003c\/strong\u003e means the primary mirror's surface is exceptionally close to a perfect parabola. For visual observers, this translates to higher contrast and sharpness, especially on challenging targets. You'll notice crisper detail in planetary cloud bands, tighter star points, and the ability to resolve faint companion stars closer to their brighter primaries. It ensures you are seeing everything the telescope's 250mm aperture is capable of resolving.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the CT10's carbon fibre tube help with astrophotography?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003ecarbon fibre sandwich tube\u003c\/strong\u003e has virtually zero thermal expansion. During a long imaging session, temperature changes can cause metal tubes to shrink, shifting the focal plane and ruining sharp focus. The CT10's tube holds focus rigidly throughout the night, preventing focus drift in your sub-exposures and resulting in consistently sharp images from start to finish.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the f\/4.8 focal ratio of the CT10 good for imaging galaxies like the Andromeda Galaxy (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the \u003cstrong\u003ef\/4.8 focal ratio\u003c\/strong\u003e is considered fast and is excellent for deep-sky imaging. It allows you to collect a significant amount of light in shorter exposure times compared to slower f\/8 or f\/10 systems. While a coma corrector (sold separately) is recommended for achieving perfect star shapes across the entire field with large camera sensors, the CT10's combination of aperture and speed makes it a powerful instrument for capturing faint details in galaxies and nebulae.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of mount is required for the Orion Optics UK CT10?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe CT10 optical tube weighs \u003cstrong\u003e11kg\u003c\/strong\u003e and the rings add another \u003cstrong\u003e1.5kg\u003c\/strong\u003e, for a total of 12.5kg (approx. 27.5 lbs) before adding a camera or other accessories. For stable astrophotography, you should choose a German Equatorial Mount with a payload capacity of at least 40-45 lbs (approx. 20kg) to ensure rigidity and accurate tracking.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Orion Optics UK CT10 for high-magnification views of Jupiter's Great Red Spot?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. The CT10 is an exceptional planetary instrument. Its guaranteed \u003cstrong\u003e1\/10 PV wavefront\u003c\/strong\u003e optics, combined with the large \u003cstrong\u003e250mm aperture\u003c\/strong\u003e for high resolution, will deliver incredibly detailed and high-contrast views of Jupiter, Saturn, and Mars when seeing conditions permit. The precision 2\" focuser with reduction gearing is crucial for achieving the critical focus needed at the high magnifications required for such observations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the benefit of the CT10's 9-point mirror cell for a 250mm mirror?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA \u003cstrong\u003e9-point flotation cell\u003c\/strong\u003e provides optimized support for the 250mm (10-inch) primary mirror. It distributes the mirror's \u003cstrong\u003e11kg\u003c\/strong\u003e weight evenly across nine points, preventing gravitational sag or flexure as the telescope moves. This ensures the mirror retains its precise 1\/10 PV shape, free from any induced astigmatism, regardless of where the telescope is pointed in the sky.\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\u003eOptics Grade\u003c\/td\u003e\n\u003ctd\u003e1\/10 PV Wavefront\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAperture\u003c\/td\u003e\n\u003ctd\u003e250mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e1200mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/4.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Mirror Glass\u003c\/td\u003e\n\u003ctd\u003eSuprax\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCoatings\u003c\/td\u003e\n\u003ctd\u003eEnhanced Hilux\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Mirror Size\u003c\/td\u003e\n\u003ctd\u003e63mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Material\u003c\/td\u003e\n\u003ctd\u003eCarbon fibre sandwich\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Diameter\u003c\/td\u003e\n\u003ctd\u003e300mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Length\u003c\/td\u003e\n\u003ctd\u003e1050mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Weight\u003c\/td\u003e\n\u003ctd\u003e11kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e2\" focuser with reduction gearing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFinder Scope\u003c\/td\u003e\n\u003ctd\u003e8x50\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMirror Cell\u003c\/td\u003e\n\u003ctd\u003eCNC machined aluminium, 9 point suspension\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpider\u003c\/td\u003e\n\u003ctd\u003eAdjustable 4 vane, stainless steel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Holder\u003c\/td\u003e\n\u003ctd\u003eMachined aluminium, rotatable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting Rings\u003c\/td\u003e\n\u003ctd\u003eCNC machined tube rings, anodised black\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRing Weight\u003c\/td\u003e\n\u003ctd\u003e1.5kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eExtension Tubes\u003c\/td\u003e\n\u003ctd\u003e40mm long, screw threaded\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBoxed Dimensions\u003c\/td\u003e\n\u003ctd\u003e128x52x52mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBoxed Weight\u003c\/td\u003e\n\u003ctd\u003e17kg\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\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/orion-optics-uk-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eOrion Optics UK 1-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Orion Optics UK","offers":[{"title":"Default Title","offer_id":52942379516189,"sku":"OOUK-CT10-OPTICAL-TUBE-ASSEMBLY","price":3111.27,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Logo_ae8497e7-2f2c-4d11-b94e-f91dc5d21578.jpg?v=1789607188","url":"https:\/\/davidastro.com\/en-us\/products\/orion-optics-uk-ct10-optical-tube-assembly","provider":"David Astro","version":"1.0","type":"link"}