{"product_id":"omegon-pro-apo-71-490-quadruplet-astrograph","title":"Omegon Pro APO AP 71\/490 Quadruplet Flat-Field Refractor OTA","description":"\u003cdiv class=\"dcs-product-description\"\u003e\n\n\u003ch2\u003eOmegon Pro APO AP 71\/490 – Compact Flat-Field Quadruplet Astrograph\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eOmegon Pro APO AP 71\/490 Quadruplet\u003c\/strong\u003e is a compact 71mm apochromatic refractor built around the needs of modern astrophotography. Its four-element ED optical system combines excellent colour correction with an \u003cstrong\u003eintegrated field corrector\u003c\/strong\u003e, giving you a flat imaging field without adding a separate field flattener to the optical train.\u003c\/p\u003e\n\n\u003cp\u003eWith a \u003cstrong\u003e490mm focal length\u003c\/strong\u003e, f\/6.9 focal ratio and \u003cstrong\u003e44mm fully corrected field\u003c\/strong\u003e, this portable Pro APO is an excellent choice for capturing nebulae, star fields, open clusters and other wide-field deep-sky targets. The telescope is also capable of high-quality visual observation when required.\u003c\/p\u003e\n\n\u003cdiv style=\"text-align:center;margin:30px 0;\"\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0523\/1650\/4241\/files\/Omegon-Apochromatic-Refractor-Pro-APO-AP-71-490-Quadruplet-OTA.jpg?v=1787645069\" alt=\"Omegon Pro APO AP 71\/490 Quadruplet apochromatic refractor OTA\" loading=\"lazy\" style=\"max-width:100%;height:auto;\"\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eFour-Element ED Optics with Integrated Field Correction\u003c\/h2\u003e\n\n\u003cp\u003eAt the heart of the Omegon Pro APO 71\/490 is a sophisticated \u003cstrong\u003equadruplet ED optical system\u003c\/strong\u003e. Four optical elements work together to control chromatic aberration while producing the flat field required for high-quality astrophotography.\u003c\/p\u003e\n\n\u003cp\u003eThe integrated corrector provides a \u003cstrong\u003e44mm fully corrected imaging field\u003c\/strong\u003e. This simplifies the imaging train and removes the need to purchase, space and configure a separate field flattener.\u003c\/p\u003e\n\n\u003cp\u003eAll lens surfaces receive effective multi-coatings to reduce unwanted reflections and improve light transmission, helping produce crisp stars, strong contrast and naturally rendered colour.\u003c\/p\u003e\n\n\u003cdiv style=\"text-align:center;margin:30px 0;\"\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0523\/1650\/4241\/files\/Omegon-Apochromatic-Refractor-Pro-APO-AP-71-490-Quadruplet-OTA_3.jpg?v=1787645067\" alt=\"Omegon 71mm quadruplet ED APO refractor optical system\" loading=\"lazy\" style=\"max-width:100%;height:auto;\"\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eDesigned for Deep-Sky Astrophotography\u003c\/h2\u003e\n\n\u003cp\u003eThe combination of \u003cstrong\u003e71mm aperture and 490mm focal length\u003c\/strong\u003e provides a highly useful field of view for deep-sky imaging. At f\/6.9, the telescope offers a good balance between image scale, optical correction and portability.\u003c\/p\u003e\n\n\u003cp\u003eIt is particularly well suited to larger emission and reflection nebulae, open star clusters, rich Milky Way regions and wide-field compositions. The relatively short focal length also makes guiding less demanding than with a long focal-length imaging telescope.\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003e71mm aperture\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003e490mm focal length\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003ef\/6.9 focal ratio\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFour-element quadruplet ED design\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eIntegrated field corrector\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003e44mm fully corrected field\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eFully multi-coated optics\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eCompact 373mm optical tube\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"text-align:center;margin:30px 0;\"\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0523\/1650\/4241\/files\/Omegon-Apochromatic-Refractor-Pro-APO-AP-71-490-Quadruplet-OTA_7.jpg?v=1787645067\" alt=\"Omegon Pro APO 71\/490 compact astrophotography refractor\" loading=\"lazy\" style=\"max-width:100%;height:auto;\"\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003e2.5-Inch Precision Focuser\u003c\/h2\u003e\n\n\u003cp\u003eA capable astrograph needs a focuser that can accurately position modern imaging equipment. The Omegon 71\/490 features a substantial \u003cstrong\u003e2.5-inch geared focuser\u003c\/strong\u003e with ball bearings for smooth, controlled movement.\u003c\/p\u003e\n\n\u003cp\u003eThe focuser can support accessories weighing up to approximately \u003cstrong\u003e4kg\u003c\/strong\u003e, making it suitable for cooled astronomy cameras and other imaging equipment. A \u003cstrong\u003e1:10 fine-focus reduction\u003c\/strong\u003e provides the precision required to reach critical focus.\u003c\/p\u003e\n\n\u003cp\u003eFocus travel is 50mm, while a ring clamp provides secure attachment for compatible equipment.\u003c\/p\u003e\n\n\u003cdiv style=\"text-align:center;margin:30px 0;\"\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0523\/1650\/4241\/files\/Omegon-Apochromatic-Refractor-Pro-APO-AP-71-490-Quadruplet-OTA_6.jpg?v=1787645068\" alt=\"Omegon Pro APO 71\/490 2.5 inch precision focuser\" loading=\"lazy\" style=\"max-width:100%;height:auto;\"\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eReady for Electronic Autofocusing\u003c\/h2\u003e\n\n\u003cp\u003eThe focuser is compatible with several popular electronic focus motors without requiring additional adapters, making the telescope particularly attractive for automated astrophotography rigs.\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eOmegon Pro Focus Motor Estia\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eZWO Electronic Automatic Focuser EAF N\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cstrong\u003eiOptron Electronic Automatic Focuser iEAF\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eElectronic focusing allows compatible astrophotography software to perform repeatable autofocus routines throughout an imaging session, helping compensate for focus changes caused by temperature variation.\u003c\/p\u003e\n\n\u003cdiv style=\"text-align:center;margin:30px 0;\"\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0523\/1650\/4241\/files\/Omegon-Apochromatic-Refractor-Pro-APO-AP-71-490-Quadruplet-OTA_4.jpg?v=1787645067\" alt=\"Omegon 71\/490 APO refractor focuser and camera connection\" loading=\"lazy\" style=\"max-width:100%;height:auto;\"\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003e360° Rotation for Precise Camera Framing\u003c\/h2\u003e\n\n\u003cp\u003eFinding the target is only part of creating a great astrophotograph. Camera orientation can be equally important, particularly when imaging elongated nebulae, galaxies or planning mosaics.\u003c\/p\u003e\n\n\u003cp\u003eThe \u003cstrong\u003e360° rotating focuser\u003c\/strong\u003e allows you to change camera orientation without rotating the optical tube or disturbing the telescope's position on the mount.\u003c\/p\u003e\n\n\u003cp\u003eThe 2-inch eyepiece adapter can also be removed to reveal an \u003cstrong\u003eM64x0.75 female thread\u003c\/strong\u003e for compatible imaging configurations.\u003c\/p\u003e\n\n\u003cdiv style=\"text-align:center;margin:30px 0;\"\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0523\/1650\/4241\/files\/Omegon-Apochromatic-Refractor-Pro-APO-AP-71-490-Quadruplet-OTA_8.jpg?v=1787645067\" alt=\"Omegon Pro APO 71\/490 rotating focuser for astrophotography camera framing\" loading=\"lazy\" style=\"max-width:100%;height:auto;\"\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eCompact, Lightweight and Portable\u003c\/h2\u003e\n\n\u003cp\u003eWith an optical tube length of approximately \u003cstrong\u003e373mm\u003c\/strong\u003e and tube weight of around \u003cstrong\u003e3kg\u003c\/strong\u003e, the 71\/490 is well suited to portable astrophotography.\u003c\/p\u003e\n\n\u003cp\u003eThe telescope includes tube rings and a \u003cstrong\u003eVixen-style dovetail rail\u003c\/strong\u003e for compatibility with a wide range of astronomy mounts. A Vixen\/Sky-Watcher style finder base also provides a convenient mounting point for a finder or compact guidescope.\u003c\/p\u003e\n\n\u003cdiv style=\"text-align:center;margin:30px 0;\"\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0523\/1650\/4241\/files\/Omegon-Apochromatic-Refractor-Pro-APO-AP-71-490-Quadruplet-OTA_1.jpg?v=1787645067\" alt=\"Omegon Pro APO 71\/490 OTA with tube rings and Vixen dovetail\" loading=\"lazy\" style=\"max-width:100%;height:auto;\"\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eMore Than an Imaging Telescope\u003c\/h2\u003e\n\n\u003cp\u003eAlthough optimised for astrophotography, the Omegon Pro APO 71\/490 can also be used visually. Its colour-corrected refractor optics make it suitable for observing the Moon and planets as well as brighter nebulae, galaxies and star fields.\u003c\/p\u003e\n\n\u003cp\u003eThe compact optical tube can also be used for terrestrial and nature observation with suitable accessories.\u003c\/p\u003e\n\n\u003ch2\u003eOmegon Pro APO AP 71\/490 Specifications\u003c\/h2\u003e\n\n\u003ctable style=\"width:100%;border-collapse:collapse;\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eType\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eApochromatic refractor\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSeries\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003ePro APO\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eOptical design\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eQuadruplet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eVariant\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eFlat-Field\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eAperture\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e71mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFocal length\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e490mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFocal ratio\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003ef\/6.9\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFully corrected field\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e44mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMaximum useful magnification\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e142x\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eLimiting magnitude\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e12.3\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFocuser\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eRack and pinion\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFine focusing\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e1:10 reduction\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFocus travel\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e50mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eRotating focuser\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eYes\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eEyepiece connection\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e2-inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eImaging thread\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eM64x0.75 female beneath adapter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eCorrector\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eIntegrated\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eTube length\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e373mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eTube weight\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e3.0kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eTotal weight\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e4.7kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eDew shield diameter\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e93mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMounting rail\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eVixen style\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFinder base\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eVixen\/Sky-Watcher style\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003cdiv style=\"text-align:center;margin:30px 0;\"\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0523\/1650\/4241\/files\/Omegon-Apochromatic-Refractor-Pro-APO-AP-71-490-Quadruplet-OTA_5.jpg?v=1787645067\" alt=\"Omegon Pro APO AP 71\/490 flat field quadruplet telescope details\" loading=\"lazy\" style=\"max-width:100%;height:auto;\"\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eWhat's Included?\u003c\/h2\u003e\n\n\u003cul\u003e\n\u003cli\u003eOmegon Pro APO AP 71\/490 Quadruplet OTA\u003c\/li\u003e\n\u003cli\u003eIntegrated field corrector\u003c\/li\u003e\n\u003cli\u003eTube clamps\u003c\/li\u003e\n\u003cli\u003eVixen-style dovetail rail\u003c\/li\u003e\n\u003cli\u003eDew shield\u003c\/li\u003e\n\u003cli\u003eExtension tubes\u003c\/li\u003e\n\u003cli\u003e1.25-inch and 2-inch eyepiece adapters\u003c\/li\u003e\n\u003cli\u003e45° 1.25-inch Amici prism\u003c\/li\u003e\n\u003cli\u003e8mm eyepiece\u003c\/li\u003e\n\u003cli\u003e20mm eyepiece\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv style=\"text-align:center;margin:30px 0;\"\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0523\/1650\/4241\/files\/Omegon-Apochromatic-Refractor-Pro-APO-AP-71-490-Quadruplet-OTA_2.jpg?v=1787645067\" alt=\"Omegon Pro APO 71\/490 quadruplet telescope included accessories\" loading=\"lazy\" style=\"max-width:100%;height:auto;\"\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eA Portable Flat-Field Astrograph for Modern Imaging\u003c\/h2\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eOmegon Pro APO AP 71\/490 Quadruplet\u003c\/strong\u003e brings together four-element ED optics, integrated field correction, a 44mm corrected field and precision focusing in a genuinely portable package.\u003c\/p\u003e\n\n\u003cp\u003eFor astrophotographers looking to build a compact deep-sky imaging rig without the complication of a separate field flattener, it offers an attractive combination of optical performance, portability and imaging-focused mechanics.\u003c\/p\u003e\n\n\u003cdiv style=\"text-align:center;margin:30px 0;\"\u003e\n\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0523\/1650\/4241\/files\/Omegon-Apochromatic-Refractor-Pro-APO-AP-71-490-Quadruplet-OTA_9.jpg?v=1787645067\" alt=\"Omegon Pro APO AP 71\/490 quadruplet flat field astrograph UK\" loading=\"lazy\" style=\"max-width:100%;height:auto;\"\u003e\n\u003c\/div\u003e\n\n\u003cp\u003e\u003cstrong\u003eAvailable from Dark Clear Skies – UK astronomy equipment specialists.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003c\/div\u003e","brand":"Omegon","offers":[{"title":"Default Title","offer_id":55639445995896,"sku":"85631","price":659.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0523\/1650\/4241\/files\/Omegon-Apochromatic-Refractor-Pro-APO-AP-71-490-Quadruplet-OTA.jpg?v=1787645069","url":"https:\/\/www.darkclearskies.co.uk\/products\/omegon-pro-apo-71-490-quadruplet-astrograph","provider":"Dark Clear Skies ","version":"1.0","type":"link"}