{"product_id":"orion-optics-uk-ct12-optical-tube-assembly","title":"Orion Optics UK CT12 Optical Tube Assembly","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e300mm (12\") Aperture f\/4 Newtonian Reflector\u003c\/li\u003e\n\u003cli\u003e1200mm Focal Length\u003c\/li\u003e\n\u003cli\u003eCertified 1\/10 PV Wavefront Primary Mirror\u003c\/li\u003e\n\u003cli\u003eCarbon Fiber Sandwich Tube Construction\u003c\/li\u003e\n\u003cli\u003e9-Point CNC-Machined Flotation Mirror Cell\u003c\/li\u003e\n\u003cli\u003e2\" Dual-Speed Focuser\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 CT12 Optical Tube Assembly\u003c\/h2\u003e\n\u003cp\u003eThe Orion Optics UK CT12 combines a fast f\/4 optical system with a massive 300mm aperture, built around a primary mirror hand-figured to a 1\/10 PV wavefront accuracy. Housed in a thermally stable carbon fiber sandwich tube measuring 1100mm long, this OTA is engineered for high-resolution planetary and deep-sky imaging where optical perfection is paramount. The 17kg assembly is supported by a 9-point flotation cell and CNC-machined rings, delivering a rigid and precise platform for capturing the finest details the night sky has to offer.\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 Wavefront Optics: The CT12's Defining Feature\u003c\/h3\u003e\n\u003cp\u003eThe heart of the CT12 is its 300mm Suprax primary mirror, which comes standard with Orion Optics UK's highest possible optical grade: 1\/10 Peak-to-Valley (PV) wavefront. This isn't an optional upgrade; it's the baseline for the CT series. This level of precision, verified by an included Zygo laser interferometer report, ensures that the telescope delivers the sharpest, highest-contrast images physically possible, limited only by atmospheric seeing.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1\/10 PV Wavefront Standard:\u003c\/strong\u003e Represents the pinnacle of mirror figuring, minimizing scattered light and maximizing fine detail on challenging targets like planetary cloud bands and tight double stars.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEnhanced Hilux Coatings:\u003c\/strong\u003e Provide superior reflectivity for brighter images and increased contrast, crucial for pulling faint deep-sky objects out of the background sky.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eZygo Test Report Included:\u003c\/strong\u003e Every CT12 ships with its own interferometry data, providing absolute proof of the primary mirror's exceptional quality and giving you full confidence in your instrument's capabilities.\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\u003eVisualizing the 1\/10 PV Advantage on High-Resolution Targets\u003c\/h3\u003e\n\u003cp\u003eA 1\/10 PV wavefront isn't just a number—it translates directly to superior performance at the eyepiece and sensor. Compared to standard 1\/4 PV or even upgraded 1\/6 PV optics, the near-perfect surface of the CT12's mirror concentrates more light into the central Airy disk of a star's image. This results in visibly higher contrast on low-contrast planetary features, like the subtle banding on Saturn or the Cassini Division in its rings, especially during moments of steady seeing.\u003c\/p\u003e\n\u003cdiv class=\"DAV-image-grid\"\u003e\n  \u003cdiv class=\"DAV-image-grid-item\"\u003e\n\u003cimg alt=\"Saturn view through 1\/4 PV optics\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Saturn-1_4-PV.jpg\"\u003e\n  \u003cp\u003e1\/4 PV (Standard)\u003c\/p\u003e\n\u003c\/div\u003e\n  \u003cdiv class=\"DAV-image-grid-item\"\u003e\n\u003cimg alt=\"Saturn view through 1\/6 PV optics\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Saturn-1_6-PV.jpg\"\u003e\n  \u003cp\u003e1\/6 PV (Professional)\u003c\/p\u003e\n\u003c\/div\u003e\n  \u003cdiv class=\"DAV-image-grid-item\"\u003e\n\u003cimg alt=\"Saturn view through 1\/8 PV optics\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Saturn-1_8-PV.jpg\"\u003e\n  \u003cp\u003e1\/8 PV (Research)\u003c\/p\u003e\n\u003c\/div\u003e\n  \u003cdiv class=\"DAV-image-grid-item\"\u003e\n\u003cimg alt=\"Saturn view through 1\/10 PV optics\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Saturn-1_10-PV.jpg\"\u003e\n  \u003cp\u003e1\/10 PV (Ultra)\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\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 Fiber Tube \u0026amp; 9-Point Cell: Stability for f\/4 Imaging\u003c\/h3\u003e\n\u003cp\u003eAt a fast f\/4 focal ratio, maintaining precise focus is critical. The CT12's carbon fiber sandwich tube, with a 350mm diameter, offers near-zero thermal expansion. This ensures the 1200mm focal length remains constant as temperatures drop overnight, eliminating the need for constant refocusing during an imaging session. The 300mm primary mirror is supported by a CNC-machined 9-point flotation cell, which prevents gravitational distortion and includes a fan for rapid thermal stabilization.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eZero-Expansion Tube:\u003c\/strong\u003e The carbon fiber construction maintains focus stability, a non-negotiable requirement for serious astrophotography with a fast optical system.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e9-Point Flotation Cell:\u003c\/strong\u003e Distributes the mirror's weight evenly to preserve its precise 1\/10 PV figure, regardless of the telescope's orientation.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eActive Cooling:\u003c\/strong\u003e An integrated fan accelerates the cooling of the primary mirror to match ambient temperature, reducing tube currents and sharpening the image faster.\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\u003ePrecision 2\" Focuser and 8x50 Finder: Critical Imaging Components\u003c\/h3\u003e\n\u003cp\u003eThe CT12 is equipped with components that match the quality of its optics. The 2\" focuser features reduction gearing for fine focus adjustments, essential for achieving sharp stars with a modern imaging sensor. For visual target acquisition, a high-quality 8x50 finder scope is included, providing a bright, wide field of view to easily locate objects before switching to the main eyepiece or camera.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDual-Speed Focuser:\u003c\/strong\u003e Allows for rapid coarse focusing and then extremely fine adjustments, critical for locking in perfect focus with the narrow focal zone of an f\/4 system.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e8x50 Finder:\u003c\/strong\u003e A substantial finder that gathers enough light to show many deep-sky objects directly, making star-hopping intuitive and fast.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncluded 40mm Extension Tube:\u003c\/strong\u003e Ensures that a wide range of eyepieces and cameras can reach focus without requiring additional accessories.\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\"\u003eWhy is the CT12's 1\/10 PV wavefront specification so important for planetary imaging?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eFor planetary imaging, contrast is everything. A \u003cstrong\u003e1\/10 PV wavefront\u003c\/strong\u003e mirror minimizes light scatter, which directly increases the contrast of fine, low-contrast details like Jupiter's cloud belts, the Great Red Spot, or subtle features on Mars. This higher precision allows you to push magnification further during moments of good seeing and resolve details that would be smeared out by optics with a lower PV rating.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the CT12's f\/4 focal ratio affect imaging of deep-sky objects like the Orion Nebula (M42)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe fast \u003cstrong\u003ef\/4 focal ratio\u003c\/strong\u003e allows the CT12 to capture photons at a much faster rate than an f\/8 or f\/10 system. When imaging a large, bright target like the Orion Nebula (M42), this means you can collect the same amount of data in significantly shorter sub-exposures. This reduces demands on your mount's tracking accuracy and allows you to build up a deep, high-signal image more efficiently.\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 17kg CT12 OTA?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith an approximate tube weight of \u003cstrong\u003e17kg\u003c\/strong\u003e (plus 2kg for rings and additional weight for a camera and guide scope), the CT12 requires a substantial equatorial mount with a high payload capacity. For imaging, you should look for a mount rated for at least 25-30kg to ensure stability and precise tracking. Mounts in the EQ6-R Pro, CGX, or higher class are recommended.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the carbon fiber tube on the CT12 really prevent focus shift during temperature changes?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. Carbon fiber has an extremely low coefficient of thermal expansion, especially compared to aluminum or steel tubes. This means that as the ambient temperature drops throughout the night, the \u003cstrong\u003e1100mm tube\u003c\/strong\u003e will not shrink, keeping the distance between the primary mirror and the focuser constant. This maintains a stable focal plane, which is critical for long imaging sessions at f\/4 where the depth of focus is very shallow.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat do I need to add to the CT12 to start observing or imaging?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe CT12 is an Optical Tube Assembly (OTA) and requires several key components to be operational. You will need:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eA suitable equatorial mount (see above).\u003c\/li\u003e\n\u003cli\u003eAt least one 2\" or 1.25\" eyepiece for visual observation (none are included).\u003c\/li\u003e\n\u003cli\u003eA collimation tool (essential for a fast Newtonian).\u003c\/li\u003e\n\u003cli\u003eA 12V power supply for the mirror's cooling fan.\u003c\/li\u003e\n\u003cli\u003eAn astronomy camera and any necessary adapters if you plan to do astrophotography.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the CT12 for high-magnification views of Jupiter in my light-polluted backyard?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. The CT12's large \u003cstrong\u003e300mm aperture\u003c\/strong\u003e provides incredible light-gathering power and high potential resolution. Light pollution primarily affects faint deep-sky objects, but bright targets like Jupiter are largely immune. The limiting factor for planetary viewing is atmospheric seeing, not light pollution. On a night with steady air, the 1\/10 PV optics will deliver exceptionally sharp and detailed views of Jupiter's atmospheric bands and its Galilean moons.\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 Quality\u003c\/td\u003e\n\u003ctd\u003e1\/10 PV wavefront (Standard)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAperture\u003c\/td\u003e\n\u003ctd\u003e300mm\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\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\u003eMirror Coatings\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\u003e75mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e2\" 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\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\u003e350mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Length\u003c\/td\u003e\n\u003ctd\u003e1100mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Weight\u003c\/td\u003e\n\u003ctd\u003e17kg (approx)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMirror Cell\u003c\/td\u003e\n\u003ctd\u003e9-point suspension, CNC machined aluminum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpider\u003c\/td\u003e\n\u003ctd\u003e4-vane stainless steel, fully adjustable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Holder\u003c\/td\u003e\n\u003ctd\u003eCNC machined aluminum, rotatable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting Rings\u003c\/td\u003e\n\u003ctd\u003eCNC machined, anodised black\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRings Weight\u003c\/td\u003e\n\u003ctd\u003e2kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eExtension Tube\u003c\/td\u003e\n\u003ctd\u003e40mm, screw threaded\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBoxed Dimensions\u003c\/td\u003e\n\u003ctd\u003eBox 1: 128x52x52mm, Box 2: 58x58x34mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBoxed Weight\u003c\/td\u003e\n\u003ctd\u003eBox 1: 14kg, Box 2: 12kg\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\"\u003eCT12 f\/4 Optical Tube 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\"\u003eCNC Machined Tube Rings\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 2\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\"\u003e8x50 Finder Scope\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\"\u003eZygo Interferometry Test Report\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\/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":52942380237085,"sku":"OOUK-CT12-OPTICAL-TUBE-ASSEMBLY","price":5702.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Logo_96e87270-bbce-4f23-845d-a9a4f25223af.jpg?v=1789607205","url":"https:\/\/davidastro.com\/products\/orion-optics-uk-ct12-optical-tube-assembly","provider":"David Astro","version":"1.0","type":"link"}