{"product_id":"orion-optics-uk-vx20","title":"Orion Optics UK VX20 DOB Optical Tube Assembly","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e500mm (20\") primary mirror for exceptional light-gathering\u003c\/li\u003e\n\u003cli\u003eFast f\/4 focal ratio, ideal for deep-sky imaging\u003c\/li\u003e\n\u003cli\u003eStandard 1\/6 PV wavefront optics, hand-figured in the UK\u003c\/li\u003e\n\u003cli\u003e9-point CNC-machined mirror cell with cooling fan\u003c\/li\u003e\n\u003cli\u003e2\" focuser with reduction gearing for precise focus control\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\u003eOrion Optics UK VX20 DOB Optical Tube Assembly\u003c\/h2\u003e\n\u003cp\u003eThe Orion Optics UK VX20 DOB Optical Tube Assembly centers on a massive 500mm primary mirror with a fast f\/4 focal ratio, delivering immense light-gathering power for observing and imaging the faintest deep-sky objects. With a nominal focal length of 2000mm, this OTA features hand-figured optics certified to a minimum 1\/6 PV wavefront accuracy, ensuring high-contrast planetary and lunar views. The primary mirror is supported by a 9-point CNC-machined cell with an integrated cooling fan to maintain thermal stability and peak optical performance.\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\u003eA 500mm f\/4 Mirror with Certified 1\/6 PV Wavefront Accuracy\u003c\/h3\u003e\n\u003cp\u003eAt the heart of the VX20 is the 500mm parabolic primary mirror, hand-finished in the UK to a guaranteed surface accuracy of 1\/6 Peak-to-Valley wavefront error or better. This level of precision, verified by a Zygo laser interferometer report supplied with every scope, goes far beyond the \"diffraction-limited\" standard. The result is visibly higher contrast, sharper stars, and the ability to resolve finer detail on planetary surfaces, limited only by atmospheric seeing.\u003c\/p\u003e\n\u003cp\u003eThe fast f\/4 focal ratio makes the VX20 an exceptional instrument for deep-sky imaging, capturing faint nebulae and distant galaxies with shorter exposure times. This optical speed, combined with the sheer aperture, provides incredibly bright, wide-field views that can frame entire star clusters and large emission nebulae in a single field with the right eyepiece.\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\u003eMechanical Design: 9-Point Cell and Truss Tube for Thermal Stability\u003c\/h3\u003e\n\u003cp\u003eA mirror of this size requires uncompromising support. The VX20 utilizes a CNC-machined, 9-point flotation mirror cell that distributes the mirror's weight evenly, preventing flexure and preserving the optical figure at any viewing angle. An integrated cooling fan accelerates thermal equilibrium, reducing tube currents and ensuring your telescope is ready for high-magnification use as quickly as possible.\u003c\/p\u003e\n\u003cp\u003eThe aluminium truss tube design provides a rigid and lightweight structure, critical for maintaining collimation as the telescope moves. With a total weight of 40kg and a length of 1945mm, the truss structure is essential for breaking the OTA down into more manageable components for transport and setup.\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\u003eImaging Interface: 2\" Reduction-Geared Focuser for Precise Control\u003c\/h3\u003e\n\u003cp\u003eAchieving critical focus at f\/4 is demanding, and the VX20 is equipped with a 2\" focuser featuring reduction gearing. This dual-speed mechanism allows for coarse adjustments to find the general focus point, followed by fine, precise movements to snap the image into perfect sharpness. This level of control is essential for both high-resolution planetary imaging and ensuring pinpoint stars in astrophotography.\u003c\/p\u003e\n\u003cp\u003eThe focuser accepts standard 2\" eyepieces and accessories, providing access to the widest possible true fields of view. For added flexibility, it is also fitted with a 1.25\" adapter, allowing you to use a full range of standard eyepieces and filters for planetary observation.\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\u003eChoosing Your Optical Grade: 1\/6 PV vs. the 1\/8 PV and 1\/10 PV Upgrades\u003c\/h3\u003e\n\u003cp\u003eWhile the standard 1\/6 PV optic delivers superb images, Orion Optics UK offers two upgrade paths for the most demanding observers. Each step represents a significant increase in the time and skill invested during the hand-figuring process, resulting in a mirror surface that more closely approaches perfection.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1\/6 PV (Professional Grade):\u003c\/strong\u003e The standard offering. Excellent for all-around observing, providing sharp, high-contrast images that outperform mass-produced optics.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1\/8 PV (Research Grade):\u003c\/strong\u003e A meaningful step up for dedicated planetary and lunar observers. This higher precision minimizes light scatter, improving the visibility of low-contrast details like subtle banding on Saturn or intricate lunar rilles.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1\/10 PV (Ultra Grade):\u003c\/strong\u003e The highest level of correction available. This grade is for those seeking the ultimate in optical performance, capable of delivering the sharpest, highest-fidelity images the 500mm aperture can theoretically produce under perfect seeing conditions.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eComparing the Optical Grades\u003c\/h3\u003e\n\u003cp\u003eThe images below show the same view of Saturn captured through each available optical grade, under identical conditions -- a visual illustration of how each step up in wavefront accuracy sharpens contrast and fine detail.\u003c\/p\u003e\n\u003cdiv class=\"DAV-comparison-grid\"\u003e\n\u003cdiv class=\"DAV-comparison-item\"\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Saturn-1_6-PV.jpg\" alt=\"Saturn viewed through 1\/6 PV Professional grade optics\"\u003e\n\u003cp\u003e1\/6 PV (Professional)\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-comparison-item\"\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Saturn-1_8-PV.jpg\" alt=\"Saturn viewed through 1\/8 PV Research grade optics\"\u003e\n\u003cp\u003e1\/8 PV (Research)\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-comparison-item\"\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Saturn-1_10-PV.jpg\" alt=\"Saturn viewed through 1\/10 PV Ultra grade optics\"\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\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 is the real-world difference between the 1\/6 PV and 1\/10 PV optics on the VX20?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe difference is most apparent during high-magnification viewing of bright objects under steady skies. While the \u003cstrong\u003e1\/6 PV\u003c\/strong\u003e optic provides excellent, sharp views, the \u003cstrong\u003e1\/10 PV Ultra\u003c\/strong\u003e optic will show a higher level of contrast and resolve finer, lower-contrast details. On Jupiter, this could mean seeing more subtle swirls and festoons within the cloud belts; on the Moon, it translates to sharper crater wall terraces and rilles.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the Orion Optics UK VX20 perform on Jupiter with its f\/4 optics?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe VX20's 500mm aperture will resolve an incredible amount of detail on Jupiter. The fast f\/4 focal ratio is primarily for wide-field, deep-sky work, but when paired with a quality Barlow lens to increase the effective focal length, it becomes a formidable planetary instrument. The certified optical quality ensures that you can push the magnification to the limit of the atmosphere, revealing intricate details in the Great Red Spot and the main equatorial belts.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the 40kg weight of the VX20 OTA manageable for setup?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e40kg\u003c\/strong\u003e weight is for the fully assembled optical tube. The truss design allows the VX20 to be broken down into smaller, lighter components: the mirror box, the upper tube assembly, and the truss poles. While still a very large instrument, this disassembly makes it significantly more manageable to transport and set up than a solid-tube telescope of a similar size. It is typically a two-person job for safe and efficient assembly.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow critical is the cooling fan for the VX20's 500mm mirror?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eFor a \u003cstrong\u003e500mm\u003c\/strong\u003e mirror, active cooling is essential. The fan dramatically reduces the time it takes for the large mirror to reach ambient temperature. Without it, the mirror would continue to radiate heat for hours, creating disruptive air currents inside the optical tube (tube currents) that blur the image and prevent sharp, high-magnification views.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat kind of views can I expect of the Dumbbell Nebula (M27) with the VX20?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith its 500mm aperture, the VX20 will provide stunning views of M27. The immense light-gathering ability will show the nebula's classic apple-core shape with remarkable brightness and clarity. With a UHC or O-III filter, you can expect to see intricate internal structures, faint outer extensions, and a clear distinction between the brighter central regions and the fainter lobes, all set against a dark sky background.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the VX20's f\/4 focal ratio require special eyepieces?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, fast f\/4 systems are demanding on eyepieces. To get sharp stars across the entire field of view, it is highly recommended to use premium eyepieces well-corrected for coma, a common aberration in fast Newtonians. Additionally, a coma corrector accessory is strongly advised, especially for imaging, to ensure pinpoint stars from edge to edge. The fast focal ratio also makes precise collimation absolutely critical for optimal performance.\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\u003eNewtonian Reflector\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Mirror Diameter\u003c\/td\u003e\n\u003ctd\u003e500mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e2000mm (nominal)\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\u003eStandard Optics Grade\u003c\/td\u003e\n\u003ctd\u003e1\/6 PV wavefront\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Upgrades\u003c\/td\u003e\n\u003ctd\u003e1\/8 PV and 1\/10 PV Ultra available\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Mirror Size\u003c\/td\u003e\n\u003ctd\u003e100mm\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\u003eMirror Cell\u003c\/td\u003e\n\u003ctd\u003e9-point CNC machined\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMirror Cooling\u003c\/td\u003e\n\u003ctd\u003eIntegrated Fan\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Type\u003c\/td\u003e\n\u003ctd\u003eTruss\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Material\u003c\/td\u003e\n\u003ctd\u003eAluminium\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Length\u003c\/td\u003e\n\u003ctd\u003e1945mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Weight\u003c\/td\u003e\n\u003ctd\u003e40kg (nominal)\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\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":"Professional (1\/6 PV)","offer_id":52942651588893,"sku":"OOUK-VX20","price":11165.0,"currency_code":"CAD","in_stock":true},{"title":"Research (1\/8 PV)","offer_id":52942651621661,"sku":"OOUK-VX20-1-8-PV-OPTICS","price":11600.0,"currency_code":"CAD","in_stock":true},{"title":"Ultra (1\/10 PV)","offer_id":52942651654429,"sku":"OOUK-VX20-1-10PV-OPTICS","price":12336.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Logo_6d378984-e56f-4039-bd8a-80fd764cfc1a.jpg?v=1789608606","url":"https:\/\/davidastro.com\/fr\/products\/orion-optics-uk-vx20","provider":"David Astro","version":"1.0","type":"link"}