{"title":"Télécompresseurs Baader Alan Gee","description":"\u003cp\u003eLe télécompresseur Baader Alan Gee est un réducteur de focale conçu pour les télescopes Schmidt-Cassegrain et les lunettes à longue focale, souvent placé devant une tête binoculaire ou un renvoi coudé. Il raccourcit la focale effective pour offrir un champ plus large et plus lumineux sans changer d'oculaires.\u003c\/p\u003e\u003cp\u003eLa gamme comprend le Telecompressor Mark II, le télécompresseur universel 2\" (UAG II), une bague de centrage pour SCT 9.25\" et un tube allonge M36.5 de 19mm pour ajuster le facteur de réduction.\u003c\/p\u003e","products":[{"product_id":"baader-alan-gee-telecompressor-mark-ii","title":"Baader Télécompresseur Alan Gee Mark II","description":"\u003c!-- more --\u003e\u003cp\u003eUne limitation courante qui afflige les propriétaires des télescopes Schmidt-Cassegrain les plus populaires est la taille de champ étroite et les grossissements élevés produits par leur système optique lent (généralement, f\/10). Jusqu'à présent, les propriétaires de SCT ne disposaient pas d'une méthode vraiment polyvalente et de haute qualité pour réduire leurs systèmes f\/10 (ou plus lents) pour des champs photographiques\/CCD et visuels plus rapides et plus larges. (Remarque : le télécompresseur n'est pas destiné à être utilisé avec les SCT f\/6.3 natifs Meade). L'utilisation de l'Alan Gee avec des oculaires de 1¼\" peut donner des champs de vision réels qui correspondent ou dépassent ce que vous ne pourriez obtenir qu'avec des oculaires coûteux de 2\" !\u003c\/p\u003e \u003cp\u003eBaader Planetarium a développé un système de télécompresseur vraiment unique et extrêmement polyvalent qui offre les meilleurs champs plats larges dont votre SCT est capable. La clé du télépresseur Alan Gee Mark II est sa conception optique et mécanique innovante. Contrairement aux solutions simples et à usage unique couramment disponibles, le Alan Gee Telecompressor Mark II a été conçu spécifiquement pour bien fonctionner avec les SCT dans une grande variété de configurations visuelles et d'imagerie. La conception unique du télépresseur Alan Gee positionne les éléments de lentille à plusieurs centimètres à l'intérieur du tube déflecteur central du télescope (voir le C8 Cutaway, qui montre la lentille montée dans la configuration d'imagerie standard). Le résultat est un champ net, large et plat, à un rapport focal rapide de f\/5,9 - et il fonctionne même parfaitement avec les visionneuses binoculaires Baader Planetarium, Zeiss et Celestron !\u003c\/p\u003e \u003cp\u003eC'est exact. L'Alan Gee Mark II est conçu pour fonctionner avec de nombreuses visionneuses binoculaires populaires. Enfin, vous pouvez utiliser votre SCT à grande ouverture pour produire de superbes vues binoculaires à grand champ. Pour plus d'informations sur ce système de télécompresseur unique, y compris des exemples d'images CCD, veuillez cliquer sur le lien ci-dessous.\u003c\/p\u003e","brand":"Baader Planetarium","offers":[{"title":"Default Title","offer_id":44967374094621,"sku":"BAA-2454400","price":401.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Baader-Alan-Gee-Telecompressor-Mark-II-1__02804.1597111079.1280.1280.jpg?v=1684341616"},{"product_id":"baader-planetarium-alan-gee-universal-2-inch-telecompressor-uag-ii","title":"Baader Planetarium Alan Gee Universal 2\" Telecompressor (UAG II)","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eUnique telecompressor designed for visual use with binoviewers\u003c\/li\u003e\n\u003cli\u003eBased on the flat-field Alan Gee design by Roland Christen of AstroPhysics\u003c\/li\u003e\n\u003cli\u003eEnables wide, 2-inch-like fields of view with 1.25\" binoviewer systems\u003c\/li\u003e\n\u003cli\u003eHoused in a standard 2\" nosepiece with a T-2 thread on the telescope side\u003c\/li\u003e\n\u003cli\u003eCompatible with Schmidt-Cassegrain and EdgeHD optical tubes\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\u003eAlan Gee Universal 2\" Telecompressor (UAG II)\u003c\/h2\u003e\n\u003cp\u003eThe Alan Gee Universal 2\" Telecompressor (UAG II) is a unique focal reducer, derived from a Roland Christen design, engineered to deliver a flat, wide field of view in Schmidt-Cassegrain telescopes. Its proven optical group is housed in a versatile 2\" barrel with T-2 threads, making it the only telecompressor on the market specifically designed to work seamlessly with binoviewers. This configuration allows you to achieve the expansive fields of a 2\" eyepiece system while using your preferred 1.25\" binoviewer.\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\u003eFlat-Field Correction for 8\" to 14\" SCTs\u003c\/h3\u003e\n\u003cp\u003eOriginally designed by Roland Christen of AstroPhysics, the Alan Gee telecompressor was created to solve the dual problems of long focal ratios and field curvature in standard Schmidt-Cassegrain telescopes. The UAG II brings this powerful optical correction to a wider audience, delivering sharp, flat fields suitable for both visual observation and imaging.\u003c\/p\u003e\n\u003cp\u003eWhile standard reducers can increase the field of view, they often introduce other aberrations. The UAG II is designed to maintain high image quality across the field, making it an ideal match for Celestron EdgeHD telescopes and other modern SCTs where edge-to-edge sharpness is critical.\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\u003eAchieve 2\" Fields with Your 1.25\" Binoviewer\u003c\/h3\u003e\n\u003cp\u003eThe standout capability of the UAG II is its compatibility with binoviewers. For years, SCT users wanting immersive, two-eyed views were limited by the narrow fields of 1.25\" systems. The UAG II eliminates this trade-off by significantly widening the field of view, creating an experience comparable to using a low-power 2\" eyepiece.\u003c\/p\u003e\n\u003cp\u003eWhen paired with a binoviewer like the Baader Maxbright® II and wide-field 1.25\" eyepieces, the UAG II can frame enormous deep-sky objects like the Andromeda Galaxy (M31) or the North American Nebula (NGC 7000) in their entirety. It provides the benefit of a 2\" system without the cost and weight of a hypothetical 2\" binoviewer.\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\u003eFlexible Connectivity: 2\" Nosepiece and T-2 Threads\u003c\/h3\u003e\n\u003cp\u003eThe UAG II is built for system flexibility. Its primary body is a 2\" nosepiece that slides directly into any 2\" diagonal or focuser, such as the Baader 2\" ClickLock clamp. For a more rigid, direct connection, the telescope side also features a T-2 female thread.\u003c\/p\u003e\n\u003cp\u003eThis T-2 thread allows you to integrate the reducer into a solid, threaded optical train, which is ideal for binoviewing. You can attach it directly to a Baader T-2 prism diagonal, which in turn connects to your binoviewer, creating a compact and secure wide-field system. The actual focal reduction is variable and depends on the back focus distance you establish between the UAG II and your eyepieces, giving you control over the final magnification.\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 makes the Alan Gee Universal Telecompressor (UAG II) different from other reducers?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe UAG II is the only telecompressor on the market specifically designed to work correctly for \u003cstrong\u003evisual observation with a binoviewer\u003c\/strong\u003e. Most reducers are optimized for imaging sensors and can introduce aberrations when used visually with the long light paths of binoviewers. The UAG II, based on a Roland Christen flat-field design, corrects for field curvature in SCTs while dramatically expanding the field of view for two-eyed observing.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the UAG II improve binoviewing on a Celestron 8\" EdgeHD telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eOn an 8\" EdgeHD or standard SCT, a binoviewer provides comfortable viewing but with a very restricted field of view. The UAG II telecompressor widens this field significantly, allowing you to see large objects in context. For example, instead of seeing just the core of the Orion Nebula (M42), you can frame the entire structure from the Trapezium out to the fainter nebulosity in a single view.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the focal reduction of the Alan Gee Universal Telecompressor (UAG II) a fixed value?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, the reduction factor is variable. It depends entirely on the \u003cstrong\u003edistance between the UAG II's optics and the eyepiece field stop\u003c\/strong\u003e (or camera sensor). A longer distance results in a stronger reduction effect and a wider field. This allows you to customize the reduction by adding or removing T-2 extension tubes in your optical train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Alan Gee Universal Telecompressor (UAG II) for imaging?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile its primary design is for visual use, especially with binoviewers, its flat-field optical design by Roland Christen makes it suitable for imaging. It can help flatten the field of standard SCTs and provide a wider perspective for cameras with smaller sensors. The variable reduction allows you to fine-tune your imaging scale.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the best way to connect the UAG II to a Baader Maxbright II Binoviewer on my SCT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eFor the most rigid and compact setup, it is recommended to build a fully T-2 threaded system. A typical high-performance configuration would be:\n\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eSCT Visual Back -\u0026gt; Baader T-2 Prism Diagonal -\u0026gt; \u003cstrong\u003eUAG II Telecompressor\u003c\/strong\u003e -\u0026gt; Baader Maxbright II Binoviewer.\u003c\/li\u003e\n\u003c\/ul\u003e\nThis creates a solid, threaded connection that prevents any flexure and ensures perfect alignment.\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I need a 2\" diagonal to use the UAG II?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNot necessarily. While the UAG II has a 2\" nosepiece that can be used in any 2\" diagonal, its real flexibility comes from the T-2 thread on the telescope side. This allows for direct integration into T-2 systems like the Baader T-2 Prism or FlipMirror II, bypassing the need for a larger 2\" diagonal entirely.\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\u003eNet weight (kg)\u003c\/td\u003e\n\u003ctd\u003e0.13\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAR-Coating\u003c\/td\u003e\n\u003ctd\u003eMulti-Coated (MC)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Design\u003c\/td\u003e\n\u003ctd\u003eField Flattener, Telecompressor\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatible telescopes\u003c\/td\u003e\n\u003ctd\u003eSchmidt-Cassegrain\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical length (mm)\u003c\/td\u003e\n\u003ctd\u003e\u0026lt; 50\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUsage\u003c\/td\u003e\n\u003ctd\u003eMaxBright II Binocular\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\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Baader_Planetarium_Universal_Alan_Gee_II_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eBaader Planetarium Universal Alan Gee II Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/baader-planetarium-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eBaader Planetarium Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Baader Planetarium","offers":[{"title":"Default Title","offer_id":52913118970141,"sku":"BAA-2454405","price":286.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/BaaderPlanetarium-Alan-Gee-Universal-2-Telecompressor-UAG-II-1_48379d86-580f-4eff-a149-5d2f283f9573.jpg?v=1789086429"},{"product_id":"baader-planetarium-m36-5-extension-tube-for-alan-gee-ii-19mm","title":"Baader Planetarium M36.5 Extension tube for Alan Gee II – 19mm","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e19mm Extension Length\u003c\/li\u003e\n\u003cli\u003eProprietary M36.5 Threading\u003c\/li\u003e\n\u003cli\u003eDesigned for the Baader Alan Gee II Telecompressor\u003c\/li\u003e\n\u003cli\u003eThin-Walled for SCT Baffle Tube Clearance\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\u003eM36.5 Extension tube for Alan Gee II – 19mm\u003c\/h2\u003e\n\u003cp\u003eThe Baader Planetarium M36.5 Extension Tube adds a crucial 19mm of spacing, a required component for achieving the designed working distance with the Alan Gee II Telecompressor on Schmidt-Cassegrain telescopes. Its proprietary M36.5 threading and thin-walled construction are purpose-built to allow the telecompressor to recess deep inside an SCT's main baffle tube, ensuring optimal field correction.\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 19mm Extension for Correct Alan Gee II Positioning\u003c\/h3\u003e\n\u003cp\u003eThe Alan Gee II Telecompressor provides a variable focal reduction from f\/5.9 down to f\/3.5, but its optical correction is highly dependent on precise spacing. This 19mm extension tube is engineered to place the telecompressor at the correct distance within an SCT's optical path. Without it, the corrector sits too far forward, preventing it from achieving its full correction potential and compromising edge-of-field sharpness.\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\u003eM36.5 Threading: A Purpose-Built Interface for SCTs\u003c\/h3\u003e\n\u003cp\u003eTo fit inside the narrow baffle tube of a C8 or similar SCT, this extension utilizes a thin-walled design with a proprietary M36.5 thread. This specific construction is a necessary trade-off; a standard, thicker T-2 extension would not physically fit. This part is intended solely to complement the Alan Gee II, allowing you to achieve perfect spacing, experiment with different working distances, or replace a lost original component.\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\"\u003eWhy do I need this 19mm M36.5 extension for my Alan Gee II on a Celestron 8\" SCT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eOn a C8, the Alan Gee II corrector must be recessed inside the main baffle tube to reach the correct working distance for optimal performance. This 19mm extension provides the exact spacing required, while its thin-walled M36.5 design allows it to physically fit where a standard T-2 extension cannot.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use this 19mm M36.5 extension to connect my Alan Gee II to a T-2 filter wheel?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. This extension uses a proprietary \u003cstrong\u003eM36.5 thread\u003c\/strong\u003e and is not compatible with the standard T-2 (M42x0.75) system. It is designed exclusively for spacing the Alan Gee II telecompressor itself.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat problem does the 19mm M36.5 extension solve for the Alan Gee II?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt solves the critical spacing problem in Schmidt-Cassegrain telescopes. Without this extension, the Alan Gee II corrector is positioned too far from the focal plane, which can lead to poor optical correction, especially at the edge of the field of view.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the 19mm M36.5 extension tube compatible with other telecompressors?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, this is a dedicated part designed specifically for the Baader Alan Gee II Telecompressor. Its unique M36.5 thread and dimensions are not intended for use with other optical accessories.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eI lost an extension for my Alan Gee II, is this the correct replacement?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The Alan Gee II system uses extensions like this to achieve different reduction factors and proper spacing. This 19mm tube is an original Baader component for replacing a lost part or for experimenting with custom spacing configurations.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhere can I find instructions for using the 19mm M36.5 extension tube?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eDetailed instructions, including diagrams showing how to configure the extensions for different reduction factors, can be found in the official manual for the \u003cstrong\u003eAlan Gee II Telecompressor\u003c\/strong\u003e.\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\u003eType of Adapter\u003c\/td\u003e\n\u003ctd\u003eExtension\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical length (mm)\u003c\/td\u003e\n\u003ctd\u003e19\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\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Baader_Planetarium_Alan_Gee_II_Telecompressor_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eBaader Planetarium Alan Gee II Telecompressor Manual\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/baader-planetarium-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eBaader Planetarium Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Baader Planetarium","offers":[{"title":"Default Title","offer_id":52913244438813,"sku":"BAA-2454411","price":30.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/BaaderPlanetarium-M36-5-Extension-tube-for-Alan-Gee-II-19mm-1_6ecca8e6-f0e7-4f5c-833c-74c95312ada5.jpg?v=1789088656"},{"product_id":"baader-planetarium-alan-gee-mark-ii-centering-ring-for-sc-9-1-4-inch","title":"Baader Planetarium Alan Gee Mark II Centering Ring for SC 9.25\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eAdapts Alan Gee II Telecompressor to larger SCTs\u003c\/li\u003e\n\u003cli\u003eEnsures precise optical alignment\u003c\/li\u003e\n\u003cli\u003eDesigned for Celestron 9.25\" and 11\" Schmidt-Cassegrain OTAs\u003c\/li\u003e\n\u003cli\u003ePrevents off-axis aberrations like coma\u003c\/li\u003e\n\u003cli\u003eRequired for optimal telecompressor imaging\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\u003eAlan Gee Mark II Centering Ring for SC 9.25\"\u003c\/h2\u003e\n\u003cp\u003eThis Alan Gee Mark II Centering Ring is the essential component for adapting the Baader Alan Gee II Telecompressor to Celestron 9.25\" and 11\" Schmidt-Cassegrain telescopes. It ensures the telecompressor is perfectly centered on the telescope's optical axis, a mandatory requirement for achieving sharp, coma-free images across the field.\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 Centering for the Alan Gee II Telecompressor\u003c\/h3\u003e\n\u003cp\u003eA telecompressor's position relative to the primary optical axis is critical. Even a slight misalignment can introduce significant off-axis aberrations, degrading image quality. This centering ring is machined to bridge the specific gap between the Alan Gee II's threads and the larger baffle tube of bigger SCTs, guaranteeing perfect axial alignment every time you attach it.\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\u003eDedicated Fit for Celestron 9.25\" and 11\" SCTs\u003c\/h3\u003e\n\u003cp\u003eThis ring is not a generic adapter; it is specifically designed for the baffle tube dimensions of Celestron's 9.25\" and 11\" SCT optical tubes. Using the telecompressor on these models without this ring will result in a poorly centered optical train, negating the benefits of the Alan Gee II's design. This component is a required part of the system for imagers using these specific telescope apertures.\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 is the purpose of the Alan Gee II Centering Ring for SC 9¼\"?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIts sole purpose is to adapt the \u003cstrong\u003eBaader Alan Gee Mark II Telecompressor\u003c\/strong\u003e for use with larger \u003cstrong\u003eCelestron 9.25\" and 11\" Schmidt-Cassegrain telescopes\u003c\/strong\u003e. It ensures the telecompressor is held perfectly on the optical axis, which is crucial for preventing image defects.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy is a specific centering ring needed for the Alan Gee II on a 9.25\" SCT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe baffle tubes of the Celestron 9.25\" and 11\" SCTs have a different diameter than the 8\" models for which the Alan Gee II was originally designed. This ring compensates for that size difference, ensuring the telecompressor's optical elements are precisely centered with the telescope's optics to avoid introducing coma and astigmatism.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs this ring compatible with Celestron 8\" SCTs or EdgeHD models?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. This ring is specifically for the non-EdgeHD Celestron 9.25\" and 11\" SCTs. The standard Alan Gee II Telecompressor attaches directly to a C8 without this ring. EdgeHD models have a different optical design and require different reducer solutions.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I install the Alan Gee II Centering Ring on my Celestron 9.25\" telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eInstallation is straightforward. You first thread the centering ring onto the rear cell of your Celestron 9.25\" or 11\" SCT. Then, you thread the Alan Gee Mark II Telecompressor into the centering ring. This ensures the entire assembly is secure and optically aligned.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Alan Gee II Telecompressor without this centering ring on my C9.25?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, you cannot. Attempting to attach the telecompressor without this ring will result in a loose fit and a severely misaligned optical train. This will produce poor quality images with significant aberrations. The ring is a mandatory component for these specific telescopes.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes this Alan Gee II Centering Ring work with other telecompressors?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis ring is designed exclusively for the Baader Alan Gee Mark II Telecompressor. It is not intended to work with reducers from other manufacturers, as thread specifications and spacing requirements can vary significantly.\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\u003eCompatibility\u003c\/td\u003e\n\u003ctd\u003eBaader Alan Gee Mark II Telecompressor\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTelescope Compatibility\u003c\/td\u003e\n\u003ctd\u003eCelestron 9.25\" and 11\" Schmidt-Cassegrain Telescopes (non-EdgeHD)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNet weight (kg)\u003c\/td\u003e\n\u003ctd\u003e0.01\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\"\u003eAlan Gee II Centering Ring for SC 9¼\"\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\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Baader_Planetarium_Alan_Gee_II_Telecompressor_Manual.pdf\" target=\"_blank\"\u003e\u003csvg class=\"DAV-img-box\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath d=\"M0 64C0 28.7 28.7 0 64 0L224 0l0 128c0 17.7 14.3 32 32 32l128 0 0 144-208 0c-35.3 0-64 28.7-64 64l0 144-48 0c-35.3 0-64-28.7-64-64L0 64zm384 64l-128 0L256 0 384 128zM176 352l32 0c30.9 0 56 25.1 56 56s-25.1 56-56 56l-16 0 0 32c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-48 0-80c0-8.8 7.2-16 16-16zm32 80c13.3 0 24-10.7 24-24s-10.7-24-24-24l-16 0 0 48 16 0zm96-80l32 0c26.5 0 48 21.5 48 48l0 64c0 26.5-21.5 48-48 48l-32 0c-8.8 0-16-7.2-16-16l0-128c0-8.8 7.2-16 16-16zm32 128c8.8 0 16-7.2 16-16l0-64c0-8.8-7.2-16-16-16l-16 0 0 96 16 0zm80-112c0-8.8 7.2-16 16-16l48 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 32 32 0c8.8 0 16 7.2 16 16s-7.2 16-16 16l-32 0 0 48c0 8.8-7.2 16-16 16s-16-7.2-16-16l0-64 0-64z\" fill=\"#0047a7\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eBaader Planetarium Alan Gee II Telecompressor Manual\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003eFor Alan Gee II Telecompressor\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/baader-planetarium-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eBaader Planetarium Warranty Policy\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Baader Planetarium","offers":[{"title":"Default Title","offer_id":52913244995869,"sku":"BAA-2454410","price":40.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/BaaderPlanetarium-Alan-Gee-Mark-II-Centering-Ring-for-SC-9-1_cb259621-4286-4607-99c5-99f605315708.jpg?v=1789088666"}],"url":"https:\/\/davidastro.com\/fr-us\/collections\/baader-alan-gee-telecompressors.oembed","provider":"David Astro","version":"1.0","type":"link"}