{"product_id":"orion-optics-uk-ct12l-optical-tube-assembly","title":"Orion Optics UK CT12L Optical Tube Assembly","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e300mm (12\") Aperture\u003c\/li\u003e\n\u003cli\u003e1590mm Focal Length, f\/5.3 Focal Ratio\u003c\/li\u003e\n\u003cli\u003eStandard 1\/10 PV Wavefront Optics\u003c\/li\u003e\n\u003cli\u003eCarbon Fibre Sandwich Tube Construction\u003c\/li\u003e\n\u003cli\u003e2\" Focuser with Reduction Gearing\u003c\/li\u003e\n\u003cli\u003e9-Point CNC Machined Mirror Cell\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 CT12L Optical Tube Assembly\u003c\/h2\u003e\n\u003cp\u003eThe Orion Optics UK CT12L is an imaging-first Newtonian built around a 300mm primary mirror hand-figured to a 1\/10 PV wavefront standard. Its 1590mm focal length delivers an f\/5.3 ratio, ideal for resolving fine detail on planets and capturing faint structures in deep-sky objects. The entire optical system is housed in a 1450mm carbon fibre sandwich tube weighing approximately 20kg, ensuring thermal stability and maintaining a precise focal plane through long imaging sessions.\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 Foundation of the 300mm System\u003c\/h3\u003e\n\u003cp\u003eThe heart of the CT12L is its 300mm Suprax primary mirror, which comes standard with Orion Optics UK's highest optical certification: a 1\/10 PV wavefront accuracy. This is not an optional upgrade but the baseline for the CT series, ensuring the highest possible contrast and sharpness. The mirror features Enhanced Hilux coatings for maximum reflectivity, and its performance is documented by an included Zygo interferometry report, providing empirical proof of its quality.\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 Tube: 1450mm of Thermally Stable Engineering\u003c\/h3\u003e\n\u003cp\u003eTo maintain the performance of its elite optics, the CT12L employs a carbon fibre sandwich tube. This advanced material has a near-zero coefficient of thermal expansion, preventing the 1590mm focal length from shifting as ambient temperature changes. The 350mm diameter tube is finished with a gloss exterior and a matte black interior to suppress stray light, providing a high-contrast backdrop for both visual observation and astrophotography.\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-inch Geared Focuser\u003c\/h3\u003e\n\u003cp\u003eThe CT12L's optical performance is supported by a robust mechanical framework. The primary mirror rests on a CNC machined 9-point flotation cell that prevents flexure and is aided by a fan for rapid thermal equalization. Up front, the 63mm secondary mirror is held by a fully adjustable, stainless steel 4-vane spider, while the 2-inch focuser with reduction gearing allows for the precise, repeatable focus adjustments necessary at an f\/5.3 focal ratio.\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 1\/10 PV Difference: Visualizing Optical Accuracy\u003c\/h3\u003e\n\u003cp\u003eOrion Optics UK offers several grades of optical accuracy, but the CT12L includes their finest 1\/10 PV grade as standard. Compared to a common 1\/4 PV \"diffraction-limited\" mirror, a 1\/10 PV surface delivers a wavefront that is significantly closer to a perfect parabola. In practice, this translates to visibly higher contrast on planetary details like Jupiter's cloud bands, tighter star points, and the ability to resolve fainter, more subtle nebulosity that would be lost in the noise of a less accurate system.\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 rating on the CT12L mean for observing?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e1\/10 Peak-to-Valley (PV) wavefront\u003c\/strong\u003e rating means the surface of the 300mm primary mirror deviates from a perfect parabola by no more than 1\/10th of a wavelength of light. This is an extremely high standard of accuracy that results in superior image contrast and sharpness. For you, the observer, this means seeing finer details on planets, resolving tighter double stars, and capturing more delicate structures in nebulae.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the CT12L's carbon fiber tube benefit astrophotography?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe carbon fiber tube has a near-zero thermal expansion coefficient. During a long imaging session, as temperatures drop overnight, a metal tube will contract and slightly change the focal length, causing images to lose focus. The \u003cstrong\u003eCT12L's 1450mm carbon fiber tube\u003c\/strong\u003e remains dimensionally stable, keeping the focal plane locked and ensuring your images remain sharp from the beginning of the night to the end without constant refocusing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the CT12L's 20kg weight manageable for a portable setup?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAt approximately \u003cstrong\u003e20kg for the tube and 2kg for the rings\u003c\/strong\u003e, the CT12L is a substantial instrument. While it can be transported to a dark sky site, it is not a grab-and-go telescope. It requires a robust equatorial mount and is best suited for a semi-permanent or observatory setup where its weight can be managed safely.\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 CT12L OTA?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith a combined weight of over 22kg (48.5 lbs) for the OTA and rings, plus the added weight of a camera, guide scope, and other accessories, you will need a heavy-duty equatorial mount. A mount with a rated payload capacity of at least 60-70 lbs is recommended to ensure stability for long-exposure astrophotography with the CT12L's 1590mm focal length.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the CT12L's f\/5.3 optics perform on faint galaxies like the Leo Triplet?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe CT12L's combination of a large \u003cstrong\u003e300mm aperture\u003c\/strong\u003e and a fast \u003cstrong\u003ef\/5.3 focal ratio\u003c\/strong\u003e is excellent for galaxy clusters. The large aperture gathers significant light to reveal faint extensions and dust lanes in galaxies like M65 and M66, while the 1\/10 PV optics ensure that the faint signal is rendered with maximum contrast against the sky background, making subtle details more visible.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat level of detail can I expect on Saturn with the CT12L's 300mm, 1\/10 PV mirror?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eUnder steady seeing conditions, the \u003cstrong\u003e300mm aperture and 1\/10 PV optics\u003c\/strong\u003e of the CT12L will provide exceptional planetary views. On Saturn, you can expect to clearly resolve the Cassini Division, subtle cloud banding on the planet's disk, and potentially the Encke Gap with excellent seeing. The high-contrast optics will also make it easier to pick out Saturn's fainter moons against the glare of the rings.\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\u003e300mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e1590mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/5.3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Mirror\u003c\/td\u003e\n\u003ctd\u003eSuprax with Enhanced Hilux Coatings\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\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\u003e1450mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Weight\u003c\/td\u003e\n\u003ctd\u003e20kg (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\u003eMachined aluminum, rotatable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRings\u003c\/td\u003e\n\u003ctd\u003eCNC machined tube rings, 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 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\u003eBox 1: 172x58x58mm, Box 2: 58x58x34mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBoxed Weight\u003c\/td\u003e\n\u003ctd\u003eBox 1: 18.5kg, 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\"\u003eCT12L 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\"\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\"\u003eCNC Machined Tube Rings\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1 Pair\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\"\u003e40mm Extension Tube\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":52942380335389,"sku":"OOUK-CT12L-OPTICAL-TUBE-ASSEMBLY","price":4590.87,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Logo_e05da382-d3e9-442f-8edc-fcc9182420bb.jpg?v=1789607213","url":"https:\/\/davidastro.com\/en-us\/products\/orion-optics-uk-ct12l-optical-tube-assembly","provider":"David Astro","version":"1.0","type":"link"}