{"product_id":"orion-optics-uk-ag16-optical-tube-assembly-only","title":"Orion Optics UK AG16 Optical Tube Assembly","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e400mm (16\") Primary Mirror Diameter\u003c\/li\u003e\n\u003cli\u003e1520mm Focal Length at a fast f\/3.8 Focal Ratio\u003c\/li\u003e\n\u003cli\u003eCorrected Flat Field Size \u0026gt;50mm\u003c\/li\u003e\n\u003cli\u003eCarbon Fibre Sandwich Tube Construction\u003c\/li\u003e\n\u003cli\u003e3\" Ceres Rack and Pinion Focuser with 10:1 Reduction\u003c\/li\u003e\n\u003cli\u003eApproximate Tube Weight of 33kg\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 AG16 Optical Tube Assembly\u003c\/h2\u003e\n\u003cp\u003eThe Orion Optics UK AG16 Astrograph is an imaging instrument engineered for large-format sensors, combining a massive 400mm primary mirror with a fast f\/3.8 focal ratio. Its integrated 4-lens ED corrector delivers a flat field greater than 50mm, producing on-axis spot sizes of just 4.1µm. The entire optical system is housed in a rigid, 1320mm carbon fibre sandwich tube weighing approximately 33kg, providing the thermal stability required for consistent focus 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\u003eThe 400mm f\/3.8 Optical System: A \u0026gt;50mm Flat Field Astrograph\u003c\/h3\u003e\n\u003cp\u003eAt the heart of the AG16 is a 400mm primary mirror operating at an aggressive f\/3.8 focal ratio, designed to capture faint signal from deep-sky objects in significantly shorter exposure times. To manage this fast optical train, a computer-designed 4-lens ED corrector is permanently installed, yielding a corrected image circle greater than 50mm in diameter. This comfortably illuminates large full-frame and medium-format astronomy sensors, ensuring sharp stars across the entire frame.\u003c\/p\u003e\n\u003cp\u003eThe optical correction achieves spot sizes of just 4.1µm on-axis and 6.6µm at the edge of the field. This level of precision allows you to resolve fine details with modern, small-pixel CMOS and CCD cameras, transforming the AG16's light-gathering power into high-resolution data.\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 Construction: Thermal Stability and Active Cooling at 33kg\u003c\/h3\u003e\n\u003cp\u003eThe AG16's optical components are housed in a 450mm diameter carbon fibre sandwich tube, a material chosen for its exceptional stiffness and low coefficient of thermal expansion. This construction minimizes focus shift as ambient temperatures change during the night, a critical factor for maintaining sharpness in an f\/3.8 system. At approximately 33kg, the tube assembly remains manageable for observatory-class mounts.\u003c\/p\u003e\n\u003cp\u003eTo accelerate mirror cooling and reduce tube currents, the primary mirror cell is equipped with three controllable fans. This active cooling system allows the large 400mm mirror to reach thermal equilibrium with the surrounding air more quickly, stabilizing the image for sharp, high-contrast viewing and imaging.\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-Ready Mechanics: 3\" Ceres Focuser and 9-Point Mirror Cell\u003c\/h3\u003e\n\u003cp\u003eThe AG16 comes standard with the robust 3\" Ceres Rack and Pinion focuser, featuring a 10:1 reduction for fine focus control. This heavy-duty focuser is designed to carry large camera packages, filter wheels, and off-axis guiders without flexure or image shift. With 79mm of focus distance available to the image plane, you have ample room to configure a complete imaging train.\u003c\/p\u003e\n\u003cp\u003eThe 400mm primary mirror is supported by a CNC machined aluminum 9-point suspension cell. This design distributes the mirror's weight evenly, preventing gravitational sag and preserving the precise optical figure required for high-resolution imaging, regardless of the telescope's orientation.\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 AG16 Advantage: 400mm Aperture vs. Portability\u003c\/h3\u003e\n\u003cp\u003eCompared to smaller astrographs in the AG series, the AG16's primary advantage is its immense 400mm aperture. This provides a significant increase in light-gathering power and resolution over 12\" or 14\" models, allowing for deeper images with shorter sub-exposures and the ability to resolve finer details in galactic structures and planetary nebulae.\u003c\/p\u003e\n\u003cp\u003eThe trade-off for this capability is size and mass. At approximately 33kg and 1320mm in length, the AG16 demands a heavy-duty, observatory-grade mount with a substantial payload capacity. While smaller AG models offer greater portability and more modest mounting requirements, the AG16 is the choice for imagers seeking the ultimate in light collection and resolving power from a fixed installation.\u003c\/p\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 the included Professional grade and the optional Ultra (Lambda\/10 PV) upgrade, under identical conditions -- a visual illustration of the difference in contrast and fine detail the upgrade delivers.\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_10-PV.jpg\" alt=\"Saturn viewed through the Ultra (Lambda\/10 PV) grade optics upgrade\"\u003e\n\u003cp\u003eLambda\/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 class of mount is required for the Orion Optics AG16 OTA?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith an approximate tube weight of 33kg (73 lbs) before adding a camera, guidescope, and other accessories, the Orion Optics AG16 requires a high-capacity, observatory-class equatorial mount. For reliable imaging, you should look for mounts rated to carry at least 45-50 kg (100-110 lbs) for astrophotography.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the AG16's f\/3.8 focal ratio affect imaging of faint nebulae like the Cygnus Loop?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe fast \u003cstrong\u003ef\/3.8 focal ratio\u003c\/strong\u003e is a major advantage for large, faint emission nebulae like the Cygnus Loop (including NGC 6960 and NGC 6992). Compared to a slower f\/8 system, the AG16 gathers light much more rapidly, allowing you to capture deep signal in a fraction of the time. This means you can achieve a higher signal-to-noise ratio with shorter individual sub-exposures, reducing the demands on your mount's tracking accuracy.\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 \u0026gt;50mm flat field on the AG16?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e\u0026gt;50mm corrected flat field\u003c\/strong\u003e ensures that stars remain sharp and round across very large imaging sensors, including full-frame (36x24mm) and some medium-format chips. Without this correction, stars at the corners of a large sensor would appear elongated or comatic in a fast Newtonian system. This makes the AG16 ideal for creating wide-field mosaics and imaging large targets like the Andromeda Galaxy (M31) without compromise.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the optical quality of the AG16's primary mirror?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis AG16 model is built with Orion Optics UK's hand-figured optics, guaranteed to a minimum accuracy of 1\/6 PV (Professional grade) wavefront as standard. The company is renowned for its rigorous testing using Zygo interferometers, and every mirror is supplied with its own test report. For imagers who want the tightest possible star images, an Ultra (Lambda\/10 PV) hand-figured optics upgrade is available.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the purpose of the three cooling fans on the AG16 mirror cell?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe three controllable fans are part of an active cooling system for the \u003cstrong\u003e400mm primary mirror\u003c\/strong\u003e. Large mirrors have significant thermal mass and can take hours to cool to ambient temperature. The fans accelerate this process, which is critical for two reasons: it minimizes tube currents that can degrade image sharpness, and it helps prevent focus shift caused by the mirror changing shape as it cools.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use a different focuser with the AG16 instead of the included Ceres?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. While the included \u003cstrong\u003e3\" Ceres focuser\u003c\/strong\u003e is a high-quality unit designed for heavy loads, Orion Optics UK can supply customized adapters for other focusers, such as the FLI Atlas. They also offer a 'FocusForm' reinforcement option to further eliminate any potential for flexure with exceptionally heavy imaging trains.\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\u003eAperture\u003c\/td\u003e\n\u003ctd\u003e400mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e1520mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/3.8\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 Length\u003c\/td\u003e\n\u003ctd\u003e1320mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Diameter\u003c\/td\u003e\n\u003ctd\u003e450mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Weight\u003c\/td\u003e\n\u003ctd\u003eapprox. 33kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Mirror Size\u003c\/td\u003e\n\u003ctd\u003e130mm\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\u003eCorrector Design\u003c\/td\u003e\n\u003ctd\u003e4-lens ED\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrected Field Size\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;50mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpot Size (On-Axis)\u003c\/td\u003e\n\u003ctd\u003e4.1µm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpot Size (Field Edge)\u003c\/td\u003e\n\u003ctd\u003e6.6µm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e79mm (from corrector)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e3\" Ceres Rack and Pinion with 10:1 reduction\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCooling System\u003c\/td\u003e\n\u003ctd\u003e3 controllable primary mirror fans\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting\u003c\/td\u003e\n\u003ctd\u003eCNC machined aluminium cradles \u0026amp; dovetail plate\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\"\u003eAG16 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 Aluminium Cradles\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\"\u003eDovetail Plate\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":"Professional (1\/6 PV)","offer_id":52942364115229,"sku":"OOUK-AG16-OPTICAL-TUBE-ASSEMBLY-ONLY","price":13945.23,"currency_code":"USD","in_stock":true},{"title":"Ultra (Lambda\/10 PV)","offer_id":52942364147997,"sku":"OOUK-AG16-OPTICAL-TUBE-ASSEMBLY-ONLY-2","price":14566.66,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Logo_8c93370b-66bc-43d6-a5d3-dda57e7c2380.jpg?v=1789606822","url":"https:\/\/davidastro.com\/en-us\/products\/orion-optics-uk-ag16-optical-tube-assembly-only","provider":"David Astro","version":"1.0","type":"link"}