{"title":"Ritchey-Chrétien \u0026 Dall-Kirkham Telescopes","description":null,"products":[{"product_id":"ioptron-photron-8-ritchey-chretien","title":"iOptron Photron 8\" Ritchey-Chrétien","description":"\u003c!-- more --\u003e\u003cp\u003e \u003cbr\u003eLes télescopes de conception iOptron® Photron™ Ritchey-Chretien sont dotés de miroirs primaires et secondaires en quartz à faible dilatation thermique avec quatre-vingt-dix-neuf pour cent de revêtements diélectriques réfléchissants. La conception optique RC offre des résultats sans coma, sans aberration sphérique et chromatique, parfaits pour l'imagerie couleur ou monochrome. Un miroir primaire à position fixe élimine le décalage d'image qui se produit lors de la mise au point avec d'autres conceptions de télescope. L'iOptron RC8 est livré avec un porte-oculaire Crayford à roulement linéaire à double vitesse de 2\". Trois bagues d'extension de porte-oculaire sont fournies pour une extension solide \"sans flexion\" afin de prendre toute mise au point arrière inutile. Son tube en acier est équipé de 10 des déflecteurs à lame de couteau pour diminuer le contraste, réduire la lumière parasite et améliorer l'instrument dans les utilisations visuelles et d'imagerie.\u003c\/p\u003e\n\u003cul\u003e\n\n \u003cli\u003eOptique sans coma, sans aberration chromatique, sans aberration sphérique\u003c\/li\u003e\n\n\u003cli\u003eOuverture optique de 200 mm (8\")\u003c\/li\u003e\n\n\u003cli\u003eDistance focale de 1624 mm\u003c\/li\u003e\n\n\u003cli\u003erapport focal f\/8\u003c\/li\u003e\n\n\u003cli\u003ePrimaire fixe\u003c\/li\u003e\n\n\u003cli\u003eMiroirs en quartz à faible dilatation thermique\u003c\/li\u003e\n\n\u003cli\u003eSystème de déflecteurs multiples à lame de couteau\u003c\/li\u003e\n\n\u003cli\u003eMise au point Crayford à double vitesse de 2\"\u003c\/li\u003e\n\n\u003cli\u003eBase du chercheur et deux barres à queue d'aronde\u003c\/li\u003e\n\n\u003cli\u003eChercheur en option, diagonale et oculaire de 1,25\"\u003c\/li\u003e\n\n\n\u003c\/ul\u003e","brand":"iOptron","offers":[{"title":"Default Title","offer_id":44968071430429,"sku":"IOP-6112","price":1649.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/iOptron-Photron-8__65470.1673470512.1280.1280.jpg?v=1684348671"},{"product_id":"ioptron-photron-6-ritchey-chretien","title":"iOptron Photron 6\" Ritchey-Chrétien","description":"\u003c!-- more --\u003e \u003cp\u003e\u003cspan\u003eLes télescopes de conception iOptron® Photron™ Ritchey-Chrétien sont dotés de miroirs primaires et secondaires en quartz à faible dilatation thermique avec quatre-vingt-dix-neuf pour cent de revêtements diélectriques réfléchissants. La conception optique RC offre des résultats sans coma, sans aberration sphérique et chromatique, parfaits pour l'imagerie couleur ou monochrome. Un miroir primaire à position fixe élimine le décalage d'image qui se produit lors de la mise au point avec d'autres conceptions de télescope. L'iOptron RC6 est livré avec un porte-oculaire Crayford à double vitesse de 2\". Trois bagues d'extension de porte-oculaire sont fournies pour une extension solide \"sans flexion\" afin de prendre en charge toute mise au point arrière inutile. Son tube en acier est équipé de déflecteurs à lame de couteau pour diminuer le contraste réduisant la lumière parasite, améliorant l'instrument à la fois dans les utilisations visuelles et d'imagerie.Un modèle RC6 est livré avec des plaques à queue d'aronde de style Vixen.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003eOptique sans coma, sans aberration chromatique, sans aberration sphérique\u003c\/li\u003e\n\n\u003cli\u003eOuverture optique de 150 mm (6\") \u003c\/li\u003e\n\n\u003cli\u003eDistance focale de 1370 mm\u003c\/li\u003e\n\n\u003cli\u003erapport focal f\/9\u003c\/li\u003e\n\n\u003cli\u003ePrimaire fixe\u003c\/li\u003e\n\n\u003cli\u003eMiroirs en quartz à faible dilatation thermique\u003c\/li\u003e\n\n\u003cli\u003eSystème de déflecteurs multiples à lame de couteau\u003c\/li\u003e\n\n\u003cli\u003ePorte-oculaire Crayford 2\" à double vitesse\u003c\/li\u003e\n\n\u003cli\u003eBase du chercheur et barre de queues d'aronde\u003c\/li\u003e\n\n\u003cli\u003eChercheur en option, diagonale et oculaire de 1,25\"\u003c\/li\u003e\n\n\u003cli\u003eMise au point électrique iOptron en option ( \u003ca href=\"http:\/\/www.ioptron.com\/product-p\/8451.htm\"\u003e#8451\u003c\/a\u003e )\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan\u003e\u003cbr\u003e\u003cstrong\u003eLe forfait comprend\u003c\/strong\u003e\u003cbr\u003e \u003cstrong\u003e#6111\u003c\/strong\u003e 6\" RC OTA uniquement\u003cbr\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003eOTA avec porte-oculaire Crayford à double vitesse de 2\"\u003c\/li\u003e\n\n\u003cli\u003eExtension de mise au point 2X25mm, 1X 50mm\u003c\/li\u003e\n\n\u003cli\u003eAdaptateur accessoire 1,25\"\u003c\/li\u003e\n\n\u003cli\u003eBarre à queue d'aronde Vixen \u003c\/li\u003e\n\n\n\u003c\/ul\u003e","brand":"iOptron","offers":[{"title":"Default Title","offer_id":44968081359133,"sku":"IOP-6111","price":781.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/ioptron-photron-6__35063.1681926345.1280.1280.jpg?v=1684348859"},{"product_id":"ioptron-photron-14-ritchey-chretien","title":"iOptron Photron 14\" Ritchey-Chrétien","description":"\u003c!-- more --\u003e\u003cp\u003e \u003cspan\u003eLa gamme Photon™ du télescope astrographe Ritchey-Chretien a été élargie avec l'ajout de quatre nouveaux modèles de tubes en treillis (10, 12, 14 et 16 pouces). Conçus pour les imageurs astro d'aujourd'hui, les télescopes RC à tube en treillis Photron™ fournissent une image claire et nette d'un bord à l'autre. Les modèles de tubes en treillis sont conçus pour perpétuer notre réputation de longue date en matière de création et de fabrication de supports de suivi solides, stables et précis, dans un télescope astrographe RC de haute qualité.\u003c\/span\u003e\u003cbr\u003e \u003cbr\u003e\u003cspan\u003eLes télescopes RC à tube en treillis iOptron® Photron ™ sont dotés de miroirs primaires et secondaires en quartz à faible dilatation thermique avec des revêtements diélectriques hautement réfléchissants maximisant la lumière atteignant votre oculaire ou votre appareil d'imagination. La conception optique RC offre des résultats sans coma, sans aberration sphérique et chromatique, parfaits pour l'imagerie couleur et monochrome. Un miroir primaire à position fixe élimine le décalage d'image qui se produit lors de la mise au point à partir d'autres conceptions de télescope. Avec une onde 1\/12e ou un miroir primaire supérieur, nos oscilloscopes RC offrent des images et des vues qui sont hors de ce monde.\u003c\/span\u003e\u003cbr\u003e \u003cbr\u003e\u003cspan\u003eChaque instrument à tube en treillis Photron est équipé d'un porte-oculaire Crayford à roulement linéaire à double vitesse qui peut faciliter notre commande de mise au point électronique conforme à l'ASCOM en option. Trois bagues d'extension de mise au point sont fournies pour une extension solide \"sans flexion\" comme moyen de prendre toute mise au point arrière inutile. Son épine dorsale, composée de supports solides et légers en fibre de carbone, maintient l'optique fermement en place tout en minimisant le poids. Sa conception en plein air permet un refroidissement rapide, réduisant le \"temps d'attente\" avant utilisation. Photron™ by iOptron®, les télescopes à tube en treillis RC sont sûrs de répondre ou de dépasser les attentes des imageurs ou des observateurs les plus exigeants.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e \u003cspan\u003e\u003cstrong\u003eCaractéristiques\u003c\/strong\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003eOptique sans coma, sans aberration chromatique, sans aberration sphérique\u003c\/li\u003e\n\n\u003cli\u003eOuverture optique de 14\" (355 mm)\u003c\/li\u003e\n\n\u003cli\u003eDistance focale de 2848 mm\u003c\/li\u003e\n\n\u003cli\u003erapport focal f\/8\u003c\/li\u003e\n\n \u003cli\u003ePrimaire fixe\u003c\/li\u003e\n\n\u003cli\u003eMiroirs en quartz à faible dilatation thermique\u003c\/li\u003e\n\n\u003cli\u003ePorte-oculaire Crayford 3\" à double vitesse\u003c\/li\u003e\n\n\u003cli\u003eMise au point électronique iOptron en option ( \u003ca href=\"http:\/\/www.ioptron.com\/product-p\/8451.htm\"\u003e#8451\u003c\/a\u003e )\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan\u003e\u003cbr\u003e\u003cstrong\u003eLe forfait comprend\u003c\/strong\u003e\u003cbr\u003e \u003cstrong\u003e#6116\u003c\/strong\u003e 14\" Truss Tube RC OTA uniquement\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\n\u003cli\u003eOTA avec porte-oculaire Crayford à double vitesse de 3\"\u003c\/li\u003e\n\n\u003cli\u003eBagues d'extension de mise au point 2X 1 \"(25,4 mm), 1X 2\" (50,8 mm)\u003c\/li\u003e\n\n\u003cli\u003eSupport de batterie pour ventilateur de refroidissement\u003c\/li\u003e\n\n\u003cli\u003eCouvertures de miroir primaire et secondaire\u003c\/li\u003e\n\n\n\u003c\/ul\u003e","brand":"iOptron","offers":[{"title":"Default Title","offer_id":44968081457437,"sku":"IOP-6116","price":9379.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/iOptron-RC-Photron-14__83140.1682950317.1280.1280.jpg?v=1684348861"},{"product_id":"ioptron-photron-10-ritchey-chretien","title":"iOptron Photron 10\" Ritchey-Chrétien ","description":"\u003c!-- more --\u003e\u003ctable class=\"colors_descriptionbox\" border=\"0\" width=\"100%\" cellspacing=\"0\" cellpadding=\"0\"\u003e\u003ctbody\u003e\u003ctr\u003e\n\n\u003ctd valign=\"top\" width=\"100%\"\u003e\u003ctable border=\"0\" width=\"100%\" cellspacing=\"0\" cellpadding=\"0\"\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd\u003e\u003cdiv id=\"ProductDetail_ProductDetails_div\"\u003e\n\n\u003cspan id=\"product_description\" itemprop=\"description\"\u003eLa gamme Photon™ du télescope astrographe Ritchey-Chretien a été élargie avec l'ajout de quatre nouveaux modèles de tubes en treillis (10, 12, 14 et 16 pouces). Conçus pour les imageurs astro d'aujourd'hui, les télescopes RC à tube en treillis Photron™ fournissent une image claire et nette d'un bord à l'autre. Les modèles de tubes en treillis sont conçus pour perpétuer notre réputation de longue date en matière de création et de fabrication de supports de suivi solides, stables et précis, dans un télescope astrographe RC de haute qualité.\u003cbr\u003e\u003c\/span\u003e \u003cbr\u003eLes télescopes RC à tube en treillis iOptron® Photron ™ sont dotés de miroirs primaires et secondaires en quartz à faible dilatation thermique avec des revêtements diélectriques hautement réfléchissants maximisant la lumière atteignant votre oculaire ou votre appareil d'imagination. La conception optique RC offre des résultats sans coma, sans aberration sphérique et chromatique, parfaits pour l'imagerie couleur et monochrome. Un miroir primaire à position fixe élimine le décalage d'image qui se produit lors de la mise au point à partir d'autres conceptions de télescope. Avec une onde 1\/12e ou un miroir primaire supérieur, nos oscilloscopes RC offrent des images et des vues qui sont hors de ce monde.\u003cbr\u003e \u003cbr\u003eChaque instrument à tube en treillis Photron est équipé d'un porte-oculaire Crayford à roulement linéaire à double vitesse qui peut faciliter notre commande de mise au point électronique conforme à l'ASCOM en option. Trois bagues d'extension de mise au point sont fournies pour une extension solide \"sans flexion\" comme moyen de prendre toute mise au point arrière inutile. Son épine dorsale, composée de supports solides et légers en fibre de carbone, maintient l'optique fermement en place tout en minimisant le poids. Sa conception en plein air permet un refroidissement rapide, réduisant le \"temps d'attente\" avant utilisation. Photron™ par iOptron®, les télescopes à tube en treillis RC sont sûrs de répondre ou de dépasser les attentes des imageurs ou des observateurs les plus exigeants.\u003cbr\u003e\u003cbr\u003e\u003cdiv\u003e\u003c\/div\u003e\n\n\u003cdiv\u003e\u003c\/div\u003e\n\n\n\u003c\/div\u003e\u003c\/td\u003e\u003c\/tr\u003e\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/td\u003e\n\n\u003ctd valign=\"middle\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_clear1x1.gif?v=1684348338\" alt=\"\" width=\"1\" height=\"1\"\u003e\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cdiv id=\"ProductDetail_ProductDetails_div2\"\u003e\u003ctable class=\"colors_descriptionbox\" border=\"0\" width=\"100%\" cellspacing=\"0\" cellpadding=\"0\"\u003e\u003ctbody\u003e\n\n\u003ctr\u003e\n\n\u003ctd valign=\"bottom\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_DBox_Border_Left_Bottom.gif?v=1684348340\" alt=\"\"\u003e\u003c\/td\u003e\n\n\u003ctd valign=\"top\" width=\"100%\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_clear1x1.gif?v=1684348338\" alt=\"\" width=\"1\" height=\"1\"\u003e\u003c\/td\u003e\n\n\u003ctd align=\"left\" valign=\"bottom\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_DBox_Border_Right_Bottom.gif?v=1684348341\" alt=\"\"\u003e\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n \u003ctr\u003e\n\n\u003ctd align=\"left\" valign=\"top\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_DBox_Border_Left_MidDiv.gif?v=1684348342\" alt=\"\"\u003e\u003c\/td\u003e\n\n\u003ctd valign=\"top\" width=\"100%\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_clear1x1.gif?v=1684348338\" alt=\"\" width=\"1\" height=\"1\"\u003e\u003c\/td\u003e\n\n\u003ctd align=\"left\" valign=\"top\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_DBox_Border_Right_MidDiv.gif?v=1684348343\" alt=\"\"\u003e\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd valign=\"middle\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_clear1x1.gif?v=1684348338\" alt=\"\" width=\"1\" height=\"1\"\u003e\u003c\/td\u003e\n\n\u003ctd valign=\"top\" width=\"100%\"\u003e\u003ctable border=\"0\" width=\"100%\" cellspacing=\"0\" cellpadding=\"0\"\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd\u003e\n\n\u003cstrong\u003eCaractéristiques\u003c\/strong\u003e\u003cbr\u003e\u003cul\u003e\n\n\u003cli\u003eOptique sans coma, sans aberration chromatique, sans aberration sphérique\u003c\/li\u003e\n\n\u003cli\u003eOuverture optique de 10\" (254 mm)\u003c\/li\u003e\n\n\u003cli\u003eDistance focale de 2032 mm\u003c\/li\u003e\n\n\u003cli\u003erapport focal f\/8\u003c\/li\u003e\n\n\u003cli\u003ePrimaire fixe\u003c\/li\u003e\n\n\u003cli\u003eMiroirs en quartz à faible dilatation thermique\u003c\/li\u003e\n\n\u003cli\u003ePorte-oculaire Crayford 3\" à double vitesse\u003c\/li\u003e\n\n\u003cli\u003eMise au point électronique iOptron en option ( \u003ca href=\"http:\/\/www.ioptron.com\/product-p\/8451.htm\"\u003e#8451\u003c\/a\u003e )\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cbr\u003e\u003cstrong\u003eLe forfait comprend\u003c\/strong\u003e \u003cbr\u003e\u003cstrong\u003e#6114\u003c\/strong\u003e\u003cspan\u003e\u003c\/span\u003e 10\" Truss Tube RC OTA uniquement\u003cbr\u003e\u003cul\u003e\n\n\u003cli\u003eOTA avec porte-oculaire Crayford à double vitesse de 3\"\u003c\/li\u003e\n\n\u003cli\u003eBagues d'extension de mise au point 2X 1 \"(25,4 mm), 1X 2\" (50,8 mm)\u003c\/li\u003e\n\n\u003cli\u003eSupport de batterie pour ventilateur de refroidissement\u003c\/li\u003e\n\n\u003cli\u003eCouvertures de miroir primaire et secondaire\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\n\u003c\/td\u003e\u003c\/tr\u003e\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\n\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/div\u003e","brand":"iOptron","offers":[{"title":"Default Title","offer_id":44968091549981,"sku":"IOP-6114","price":4477.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/6114-4__81737.1683224337.1280.1280.jpg?v=1684348984"},{"product_id":"ioptron-photron-12-ritchey-chretien","title":"iOptron Photron 12\" Ritchey-Chrétien ","description":"\u003c!-- more --\u003e\u003ctable class=\"colors_descriptionbox\" border=\"0\" width=\"100%\" cellspacing=\"0\" cellpadding=\"0\"\u003e\u003ctbody\u003e\u003ctr\u003e\n\n\u003ctd valign=\"top\" width=\"100%\"\u003e\u003ctable border=\"0\" width=\"100%\" cellspacing=\"0\" cellpadding=\"0\"\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd\u003e \u003cdiv id=\"ProductDetail_ProductDetails_div\"\u003e\n\n\u003cspan id=\"product_description\" itemprop=\"description\"\u003eLa gamme Photon™ du télescope astrographe Ritchey-Chretien a été élargie avec l'ajout de quatre nouveaux modèles de tubes en treillis (10, 12, 14 et 16 pouces). Conçus pour les imageurs astro d'aujourd'hui, les télescopes RC à tube en treillis Photron™ fournissent une image claire et nette d'un bord à l'autre. Les modèles de tubes en treillis sont conçus pour perpétuer notre réputation de longue date en matière de création et de fabrication de supports de suivi solides, stables et précis, dans un télescope astrographe RC de haute qualité.\u003cbr\u003e\u003c\/span\u003e \u003cbr\u003eLes télescopes RC à tube en treillis iOptron® Photron ™ sont dotés de miroirs primaires et secondaires en quartz à faible dilatation thermique avec des revêtements diélectriques hautement réfléchissants maximisant la lumière atteignant votre oculaire ou votre appareil d'imagination. La conception optique RC offre des résultats sans coma, sans aberration sphérique et chromatique, parfaits pour l'imagerie couleur et monochrome. Un miroir primaire à position fixe élimine le décalage d'image qui se produit lors de la mise au point à partir d'autres conceptions de télescope. Avec une onde 1\/12e ou un miroir primaire supérieur, nos oscilloscopes RC offrent des images et des vues qui sont hors de ce monde.\u003cbr\u003e \u003cbr\u003eChaque instrument à tube en treillis Photron est équipé d'un porte-oculaire Crayford à roulement linéaire à double vitesse qui peut faciliter notre commande de mise au point électronique conforme à l'ASCOM en option. Trois bagues d'extension de mise au point sont fournies pour une extension solide \"sans flexion\" comme moyen de prendre toute mise au point arrière inutile. Son épine dorsale, composée de supports solides et légers en fibre de carbone, maintient l'optique fermement en place tout en minimisant le poids. Sa conception en plein air permet un refroidissement rapide, réduisant le \"temps d'attente\" avant utilisation. Photron™ par iOptron®, les télescopes à tube en treillis RC sont sûrs de répondre ou de dépasser les attentes des imageurs ou des observateurs les plus exigeants.\u003cbr\u003e\u003cbr\u003e\u003cdiv\u003e\u003c\/div\u003e\n\n\u003cdiv\u003e\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\u003c\/td\u003e\u003c\/tr\u003e\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/td\u003e\n\n\u003ctd valign=\"middle\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_clear1x1.gif?v=1684348338\" alt=\"\" width=\"1\" height=\"1\"\u003e\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cdiv id=\"ProductDetail_ProductDetails_div2\"\u003e\u003ctable class=\"colors_descriptionbox\" border=\"0\" width=\"100%\" cellspacing=\"0\" cellpadding=\"0\"\u003e\u003ctbody\u003e\n\n\u003ctr\u003e\n\n\u003ctd valign=\"bottom\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_DBox_Border_Left_Bottom.gif?v=1684348340\" alt=\"\"\u003e\u003c\/td\u003e\n\n\u003ctd valign=\"top\" width=\"100%\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_clear1x1.gif?v=1684348338\" alt=\"\" width=\"1\" height=\"1\"\u003e\u003c\/td\u003e\n\n\u003ctd align=\"left\" valign=\"bottom\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_DBox_Border_Right_Bottom.gif?v=1684348341\" alt=\"\"\u003e\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n \u003ctr\u003e\n\n\u003ctd align=\"left\" valign=\"top\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_DBox_Border_Left_MidDiv.gif?v=1684348342\" alt=\"\"\u003e\u003c\/td\u003e\n\n\u003ctd valign=\"top\" width=\"100%\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_clear1x1.gif?v=1684348338\" alt=\"\" width=\"1\" height=\"1\"\u003e\u003c\/td\u003e\n\n\u003ctd align=\"left\" valign=\"top\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_DBox_Border_Right_MidDiv.gif?v=1684348343\" alt=\"\"\u003e\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd valign=\"middle\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_clear1x1.gif?v=1684348338\" alt=\"\" width=\"1\" height=\"1\"\u003e\u003c\/td\u003e\n\n\u003ctd valign=\"top\" width=\"100%\"\u003e\u003ctable border=\"0\" width=\"100%\" cellspacing=\"0\" cellpadding=\"0\"\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd\u003e\n\n\u003cstrong\u003eCaractéristiques\u003c\/strong\u003e\u003cbr\u003e\u003cul\u003e\n\n\u003cli\u003eOptique sans coma, sans aberration chromatique, sans aberration sphérique\u003c\/li\u003e\n\n\u003cli\u003eOuverture optique de 12\" (304 mm)\u003c\/li\u003e\n\n\u003cli\u003eDistance focale de 2432 mm\u003c\/li\u003e\n\n\u003cli\u003erapport focal f\/8\u003c\/li\u003e\n\n\u003cli\u003ePrimaire fixe\u003c\/li\u003e\n\n\u003cli\u003eMiroirs en quartz à faible dilatation thermique\u003c\/li\u003e\n\n\u003cli\u003ePorte-oculaire Crayford 3\" à double vitesse\u003c\/li\u003e\n\n\u003cli\u003eMise au point électronique iOptron en option ( \u003ca href=\"http:\/\/www.ioptron.com\/product-p\/8451.htm\"\u003e#8451\u003c\/a\u003e )\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cbr\u003e\u003cstrong\u003eLe forfait comprend\u003c\/strong\u003e \u003cbr\u003e\u003cstrong\u003e#6115\u003c\/strong\u003e\u003cspan\u003e\u003c\/span\u003e 12\" Truss Tube RC OTA uniquement\u003cbr\u003e\u003cul\u003e\n\n\u003cli\u003eOTA avec porte-oculaire Crayford à double vitesse de 3\"\u003c\/li\u003e\n\n\u003cli\u003eBagues d'extension de mise au point 2X 1 \"(25,4 mm), 1X 2\" (50,8 mm)\u003c\/li\u003e\n\n\u003cli\u003eSupport de batterie pour ventilateur de refroidissement\u003c\/li\u003e\n\n\u003cli\u003eCouvertures de miroir primaire et secondaire\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\n\u003c\/td\u003e\u003c\/tr\u003e\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/td\u003e\n\n\u003ctd valign=\"middle\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_clear1x1.gif?v=1684348338\" alt=\"\" width=\"1\" height=\"1\"\u003e\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd valign=\"bottom\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_DBox_Border_Left_Bottom.gif?v=1684348340\" alt=\"\"\u003e\u003c\/td\u003e\n\n\u003ctd valign=\"top\" width=\"100%\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_clear1x1.gif?v=1684348338\" alt=\"\" width=\"1\" height=\"1\"\u003e\u003c\/td\u003e\n\n\u003ctd align=\"left\" valign=\"bottom\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_DBox_Border_Right_Bottom.gif?v=1684348341\" alt=\"\"\u003e\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\n\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/div\u003e","brand":"iOptron","offers":[{"title":"Default Title","offer_id":44968091582749,"sku":"IOP-6115","price":5821.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/6115-2__65464.1683224704.1280.1280.jpg?v=1684348985"},{"product_id":"ioptron-photron-16-ritchey-chretien","title":"iOptron Photron 16\" Ritchey-Chrétien ","description":"\u003c!-- more --\u003e\u003ctable class=\"colors_descriptionbox\" border=\"0\" width=\"100%\" cellspacing=\"0\" cellpadding=\"0\"\u003e\u003ctbody\u003e\u003ctr\u003e\n\n\u003ctd valign=\"top\" width=\"100%\"\u003e\u003ctable border=\"0\" width=\"100%\" cellspacing=\"0\" cellpadding=\"0\"\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd\u003e \u003cdiv id=\"ProductDetail_ProductDetails_div\"\u003e\n\n\u003cspan id=\"product_description\" itemprop=\"description\"\u003eLa gamme Photon™ du télescope astrographe Ritchey-Chretien a été élargie avec l'ajout de quatre nouveaux modèles de tubes en treillis (10, 12, 14 et 16 pouces). Conçus pour les imageurs astro d'aujourd'hui, les télescopes RC à tube en treillis Photron™ fournissent une image claire et nette d'un bord à l'autre. Les modèles de tubes en treillis sont conçus pour perpétuer notre réputation de longue date en matière de création et de fabrication de supports de suivi solides, stables et précis, dans un télescope astrographe RC de haute qualité.\u003cbr\u003e\u003c\/span\u003e \u003cbr\u003eLes télescopes RC à tube en treillis iOptron® Photron ™ sont dotés de miroirs primaires et secondaires en quartz à faible dilatation thermique avec des revêtements diélectriques hautement réfléchissants maximisant la lumière atteignant votre oculaire ou votre appareil d'imagination. La conception optique RC offre des résultats sans coma, sans aberration sphérique et chromatique, parfaits pour l'imagerie couleur et monochrome. Un miroir primaire à position fixe élimine le décalage d'image qui se produit lors de la mise au point à partir d'autres conceptions de télescope. Avec une onde 1\/12e ou un miroir primaire supérieur, nos oscilloscopes RC offrent des images et des vues qui sont hors de ce monde.\u003cbr\u003e \u003cbr\u003eChaque instrument à tube en treillis Photron est équipé d'un porte-oculaire Crayford à roulement linéaire à double vitesse qui peut faciliter notre commande de mise au point électronique conforme à l'ASCOM en option. Trois bagues d'extension de mise au point sont fournies pour une extension solide \"sans flexion\" comme moyen de prendre toute mise au point arrière inutile. Son épine dorsale, composée de supports solides et légers en fibre de carbone, maintient l'optique fermement en place tout en minimisant le poids. Sa conception en plein air permet un refroidissement rapide, réduisant le \"temps d'attente\" avant utilisation. Photron™ par iOptron®, les télescopes à tube en treillis RC sont sûrs de répondre ou de dépasser les attentes des imageurs ou des observateurs les plus exigeants.\u003cbr\u003e\u003cbr\u003e\u003cdiv\u003e\u003c\/div\u003e\n\n\u003cdiv\u003e\u003c\/div\u003e\n\n\n\u003c\/div\u003e\n\u003c\/td\u003e\u003c\/tr\u003e\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/td\u003e\n\n\u003ctd valign=\"middle\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_clear1x1.gif?v=1684348338\" alt=\"\" width=\"1\" height=\"1\"\u003e\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cdiv id=\"ProductDetail_ProductDetails_div2\"\u003e\u003ctable class=\"colors_descriptionbox\" border=\"0\" width=\"100%\" cellspacing=\"0\" cellpadding=\"0\"\u003e\u003ctbody\u003e\n\n\u003ctr\u003e\n\n\u003ctd valign=\"bottom\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_DBox_Border_Left_Bottom.gif?v=1684348340\" alt=\"\"\u003e\u003c\/td\u003e\n\n\u003ctd valign=\"top\" width=\"100%\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_clear1x1.gif?v=1684348338\" alt=\"\" width=\"1\" height=\"1\"\u003e\u003c\/td\u003e\n\n\u003ctd align=\"left\" valign=\"bottom\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_DBox_Border_Right_Bottom.gif?v=1684348341\" alt=\"\"\u003e\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n \u003ctr\u003e\n\n\u003ctd align=\"left\" valign=\"top\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_DBox_Border_Left_MidDiv.gif?v=1684348342\" alt=\"\"\u003e\u003c\/td\u003e\n\n\u003ctd valign=\"top\" width=\"100%\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_clear1x1.gif?v=1684348338\" alt=\"\" width=\"1\" height=\"1\"\u003e\u003c\/td\u003e\n\n\u003ctd align=\"left\" valign=\"top\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_DBox_Border_Right_MidDiv.gif?v=1684348343\" alt=\"\"\u003e\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\u003ctr\u003e\n\n\u003ctd valign=\"middle\" width=\"1\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/t\/7\/assets\/description_image_clear1x1.gif?v=1684348338\" alt=\"\" width=\"1\" height=\"1\"\u003e\u003c\/td\u003e\n\n\u003ctd valign=\"top\" width=\"100%\"\u003e\u003ctable border=\"0\" width=\"100%\" cellspacing=\"0\" cellpadding=\"0\"\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd\u003e\n\n\u003cstrong\u003eCaractéristiques\u003c\/strong\u003e\u003cbr\u003e\u003cul\u003e\n\n\u003cli\u003eOptique sans coma, sans aberration chromatique, sans aberration sphérique\u003c\/li\u003e\n\n\u003cli\u003eOuverture optique de 16\" (406 mm)\u003c\/li\u003e\n\n\u003cli\u003eDistance focale de 3250 mm\u003c\/li\u003e\n\n\u003cli\u003erapport focal f\/8\u003c\/li\u003e\n\n\u003cli\u003ePrimaire fixe\u003c\/li\u003e\n\n\u003cli\u003eMiroirs en quartz à faible dilatation thermique\u003c\/li\u003e\n\n\u003cli\u003ePorte-oculaire Crayford 3\" à double vitesse\u003c\/li\u003e\n\n\u003cli\u003eMise au point électronique iOptron en option ( \u003ca href=\"http:\/\/www.ioptron.com\/product-p\/8451.htm\"\u003e#8451\u003c\/a\u003e )\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\u003cbr\u003e\u003cstrong\u003eLe forfait comprend\u003c\/strong\u003e \u003cbr\u003e\u003cstrong\u003e#6117\u003c\/strong\u003e\u003cspan\u003e\u003c\/span\u003e 16\" Truss Tube RC OTA uniquement\u003cbr\u003e\u003cul\u003e\n\n\u003cli\u003eOTA avec porte-oculaire Crayford à double vitesse de 3\"\u003c\/li\u003e\n\n\u003cli\u003eBagues d'extension de mise au point 2X 1 \"(25,4 mm), 1X 2\" (50,8 mm)\u003c\/li\u003e\n\n\u003cli\u003eSupport de batterie pour ventilateur de refroidissement\u003c\/li\u003e\n\n\u003cli\u003eCouvertures de miroir primaire et secondaire\u003c\/li\u003e\n\n\n\u003c\/ul\u003e\n\n\n\u003c\/td\u003e\u003c\/tr\u003e\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/td\u003e\n\n\n\u003c\/tr\u003e\n\n\n\u003c\/tbody\u003e\u003c\/table\u003e\u003c\/div\u003e","brand":"iOptron","offers":[{"title":"Default Title","offer_id":44968091615517,"sku":"IOP-6117","price":12319.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/6117-2__46241.1683224893.1280.1280.jpg?v=1684348987"},{"product_id":"ioptron-6113","title":"iOptron Photron™ 10-inch Ritchey-Chrétien Telescope (RC10) 3'' Focuser","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e250mm (10-inch) Ritchey-Chrétien Optical Design\u003c\/li\u003e\n\u003cli\u003e2000mm Focal Length at f\/8\u003c\/li\u003e\n\u003cli\u003e0.46 arc second Resolving Power\u003c\/li\u003e\n\u003cli\u003e3-inch Dual Speed Focuser\u003c\/li\u003e\n\u003cli\u003e35 lb Steel Tube with Three Cooling Fans\u003c\/li\u003e\n\u003cli\u003eDual Losmandy-style Dovetail Bars\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\u003ePhotron™ 10-inch Ritchey-Chrétien Telescope (RC10) 3'' Focuser\u003c\/h2\u003e\n\u003cp\u003eThe Photron™ RC10 combines a large 250mm aperture with a 2000mm focal length in a native f\/8 Ritchey-Chrétien optical design, delivering a coma-free imaging field ideal for modern sensors. This astrograph achieves a theoretical resolving power of 0.46 arc seconds, enabling you to capture fine details in distant galaxies and planetary nebulae. The robust imaging platform is built around a heavy-duty 3-inch dual-speed focuser and a 35 lb steel optical tube equipped with three primary mirror cooling fans for rapid thermal stabilization.\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\u003e10-inch f\/8 Ritchey-Chrétien Optics: 0.46 Arc Second Resolution\u003c\/h3\u003e\n\u003cp\u003eThe Ritchey-Chrétien configuration uses hyperbolic primary and secondary mirrors to eliminate coma, an optical aberration that distorts stars at the edge of the field in other reflector designs. With a 250mm clear aperture and 2000mm focal length, the Photron RC10 provides the image scale necessary for resolving small targets like the Whirlpool Galaxy (M51) or the Ring Nebula (M57). The system's 0.46 arc second resolution and 14.7 limiting magnitude give you the power to pull in faint details from your backyard observatory.\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\u003e3-inch Dual-Speed Focuser: Support for Heavy Imaging Payloads\u003c\/h3\u003e\n\u003cp\u003eA key feature of the RC10 is its massive 3-inch dual-speed focuser, a significant upgrade for serious imagers. This large-format focuser minimizes vignetting on full-frame and larger sensors and provides the rigidity to carry heavy camera packages, filter wheels, and off-axis guiders without flexure. The fine-focus knob is critical for achieving sharp stars at the 2000mm focal length. To accommodate a wide range of cameras and accessories, the telescope includes two 1-inch and one 2-inch extension tubes to correctly set the back focus distance.\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\u003e35 lb Steel Tube Construction with Active Cooling\u003c\/h3\u003e\n\u003cp\u003eThe Photron RC10 is built with a steel tube, which provides excellent rigidity and thermal stability, though it contributes to a total OTA weight of 35 lbs. To combat thermal currents inside the closed tube, three built-in fans are mounted behind the primary mirror to accelerate cooling to ambient temperature, reducing tube seeing and ensuring the sharpest possible images. The OTA is equipped with two Losmandy-style dovetail bars—one for mounting to your equatorial mount and a second on top for attaching guide scopes, computers, or other accessories.\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\u003ePhotron RC10 vs. Other 10\" RCs: Focuser and Tube Material\u003c\/h3\u003e\n\u003cp\u003eWhen comparing the Photron RC10 to other 10-inch Ritchey-Chrétien telescopes, such as those from GSO or Astro-Tech, the primary differences lie in the focuser and tube material.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompetitor Advantage:\u003c\/strong\u003e Many competing 10\" RCs are available with carbon fiber tubes. Carbon fiber is lighter than steel and has a lower coefficient of thermal expansion, which can reduce the need for focus adjustments during temperature drops.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePhotron RC10 Advantage:\u003c\/strong\u003e The included 3-inch focuser on the Photron is a significant upgrade over the 2-inch focusers commonly found on standard models. For imagers using large sensors or heavy equipment, the larger, more robust focuser of the RC10 is a decisive benefit that prevents both vignetting and mechanical flex.\u003c\/li\u003e\n\u003c\/ul\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 kind of mount does the Photron RC10 require?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Photron RC10 has an optical tube weight of \u003cstrong\u003e35 lbs\u003c\/strong\u003e. For astrophotography, you should add the weight of your camera, guide scope, and all accessories, which can easily bring the total payload to 40-45 lbs. A mount with a payload capacity of at least 50-60 lbs, such as an iOptron CEM60\/70 or Celestron CGX, is recommended for stable, long-exposure imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Photron RC10 good for imaging small galaxies like the Sombrero Galaxy (M104)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, absolutely. The \u003cstrong\u003e2000mm focal length\u003c\/strong\u003e provides the ideal image scale for capturing details in smaller deep-sky objects like M104 or planetary nebulae like the Dumbbell Nebula (M27). The coma-free field ensures that stars across the frame remain sharp, highlighting the structure of your target.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the Photron RC10 need a field flattener or reducer?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile the Ritchey-Chrétien design is inherently free of coma, it does have natural field curvature. For cameras with smaller sensors (APS-C or smaller), this may not be noticeable. However, for full-frame or larger sensors, a dedicated field flattener is recommended to achieve perfectly sharp stars across the entire image. Reducers are also available to shorten the focal ratio for wider-field imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Photron RC10 for visual observing?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYou can, but it is not its primary design purpose. RCs are optimized for photographic use. The large \u003cstrong\u003e110mm secondary mirror\u003c\/strong\u003e creates a significant central obstruction, which reduces image contrast compared to a Newtonian or refractor of similar aperture. While planets and bright objects will be sharp, it will not deliver the same high-contrast views as a dedicated visual telescope.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy are there three extension tubes included with the Photron RC10?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eRitchey-Chrétien telescopes have a long back focus distance to accommodate various imaging accessories. The included \u003cstrong\u003e1-inch (x2) and 2-inch (x1) extension tubes\u003c\/strong\u003e are used to bridge the gap between the focuser and your camera's sensor. The combination you use will depend on your specific imaging train, whether you're using a DSLR, a cooled CMOS camera, an off-axis guider, or a filter wheel.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow difficult is it to collimate the Photron RC10?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eCollmating an RC is more involved than a Newtonian or SCT because both the primary and secondary mirrors are adjustable and hyperbolic. It requires patience and precision, and typically involves using a Cheshire eyepiece and a high-quality laser collimator. However, once collimated, a well-built RC like the Photron RC10 tends to hold its alignment very well.\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\u003eRitchey-Chretien\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eClear Aperture\u003c\/td\u003e\n\u003ctd\u003e250mm (10\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e2000mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResolving Power\u003c\/td\u003e\n\u003ctd\u003e0.46 arc seconds\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLimiting Magnitude\u003c\/td\u003e\n\u003ctd\u003e14.7\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHighest Useful Magnification\u003c\/td\u003e\n\u003ctd\u003e295X\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Mirror Diameter\u003c\/td\u003e\n\u003ctd\u003e110mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e3\" dual speed focuser\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser Drawtube Size\u003c\/td\u003e\n\u003ctd\u003e3.3”\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Mirror Cooling\u003c\/td\u003e\n\u003ctd\u003eThree built-in fans (battery holder included)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Material\u003c\/td\u003e\n\u003ctd\u003eSteel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Length\u003c\/td\u003e\n\u003ctd\u003e28.4”\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Weight\u003c\/td\u003e\n\u003ctd\u003e35 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting Dovetail (Bottom)\u003c\/td\u003e\n\u003ctd\u003eLosmandy-style\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAccessory Dovetail (Top)\u003c\/td\u003e\n\u003ctd\u003eLosmandy-style\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFinderscope Base\u003c\/td\u003e\n\u003ctd\u003eInstalled\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShipping Weight\u003c\/td\u003e\n\u003ctd\u003e48 lbs\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShipping Dimensions\u003c\/td\u003e\n\u003ctd\u003e34.5\" x 17\" x 16.75\"\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\"\u003ePhotron 10\" f\/8 Ritchey-Chrétien OTA\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\"\u003e2\" 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\"\u003e1\" Extension Tube\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 2\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\"\u003e2\" to 1.25\" Compression Ring Adapter\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\n\u003cli\u003e\n\u003ca href=\"#\" rel=\"noopener\" target=\"_blank\"\u003ePhotron Manufacturer's Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"iOptron","offers":[{"title":"Default Title","offer_id":52917293351197,"sku":"IOP-6113","price":4043.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/iOptron-Photron-10-inch-Ritchey-Chr-tien-Telescope-RC10-3-Focuser-1_a6043c6d-be43-498f-baa2-bcaa743362b9.jpg?v=1789142084"},{"product_id":"orion-optics-uk-odk10-optical-tube-assembly","title":"Orion Optics UK ODK10 Optical Tube Assembly","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e250mm (10\") Corrected Dall-Kirkham Optics\u003c\/li\u003e\n\u003cli\u003e1700mm Focal Length at f\/6.8\u003c\/li\u003e\n\u003cli\u003e50mm Fully Corrected Flat Image Circle\u003c\/li\u003e\n\u003cli\u003e3.5μm On-Axis Spot Size\u003c\/li\u003e\n\u003cli\u003eCarbon Fibre Sandwich Tube Construction\u003c\/li\u003e\n\u003cli\u003e3\" Crayford Focuser with 10:1 Reduction\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 ODK10 Optical Tube Assembly\u003c\/h2\u003e\n\u003cp\u003eThe Orion Optics UK ODK10 is an astrograph engineered for the dedicated imager, combining a 250mm primary mirror and a fast f\/6.8 focal ratio to capture deep-sky objects with exceptional detail. Its integrated 3-lens corrector delivers a 50mm flat field, producing spot sizes as small as 3.5μm on-axis and 6.2μm at the edge of the frame. With a generous 213mm of back focus and a thermally inert carbon fibre tube, the ODK10 supports complex imaging trains and maintains stable focus across temperature changes during a long night of 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\u003eODK f\/6.8 Optical Design: 250mm Aperture and 1700mm Focal Length\u003c\/h3\u003e\n\u003cp\u003eThe heart of the ODK10 is its Corrected Dall-Kirkham optical system. This design uses a 250mm primary mirror to achieve a 1700mm focal length, striking a balance between wide-field deep-sky imaging and high-resolution planetary work. The native f\/6.8 focal ratio is significantly faster than standard Schmidt-Cassegrains, allowing you to collect more light in less time and reduce total exposure duration for faint targets.\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\u003eFull-Frame Imaging: A 50mm Flat Field with 6.2μm Edge Spots\u003c\/h3\u003e\n\u003cp\u003eUnlike conventional reflector designs that suffer from off-axis coma, the ODK10 incorporates a multi-coated 3-lens corrector to produce a natively flat 50mm image circle. This is large enough to accommodate full-frame (35mm) sensors without vignetting or distortion. The optical correction is superb, yielding tight, round stars with a spot size of just 6.2μm at the very edge of the field, ensuring your images are sharp from corner to corner.\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\u003eThermally Stable Engineering: Carbon Fibre Tube and 3 Cooling Fans\u003c\/h3\u003e\n\u003cp\u003eFocus stability is critical for long-exposure astrophotography. The ODK10 addresses this with a carbon fibre sandwich tube that exhibits virtually zero thermal expansion, preventing the focal plane from shifting as ambient temperature drops. Weighing approximately 12kg and measuring only 530mm long, the open-tube design is further enhanced by three controllable fans behind the primary mirror, ensuring rapid thermal acclimation and minimizing tube currents.\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\u003eHeavy-Duty Imaging Train: 3\" Focuser and 213mm of Back Focus\u003c\/h3\u003e\n\u003cp\u003eThe ODK10 is built to carry modern imaging loads. It features a robust 3\" Crayford focuser with a 10:1 fine reduction knob for precise focus adjustments, even with heavy equipment. An exceptionally generous 213mm of back focal distance provides ample room to install complex imaging trains, including off-axis guiders, large filter wheels, and camera rotators, without running out of focus travel.\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\u003eODK10 vs. a 10\" SCT: The Benefits of a Corrected Astrograph\u003c\/h3\u003e\n\u003cp\u003eWhile a 10\" Schmidt-Cassegrain Telescope (SCT) is a capable instrument, the ODK10 offers distinct advantages for the serious imager. The SCT's primary mirror focusing can introduce image shift, a problem eliminated by the ODK10's fixed mirror and external focuser.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eNative Speed and Field:\u003c\/strong\u003e The ODK10's native f\/6.8 is faster than a typical f\/10 SCT, reducing exposure times. More importantly, its 50mm corrected flat field is built-in, whereas an SCT requires an additional, expensive reducer\/corrector to achieve a similar result.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThermal Management:\u003c\/strong\u003e The ODK10's open tube and three cooling fans allow it to reach thermal equilibrium much faster than a closed-tube SCT, resulting in sharper images sooner.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBack Focus:\u003c\/strong\u003e With 213mm of back focus, the ODK10 easily accommodates more accessories than most standard SCTs, providing greater flexibility for your imaging setup.\u003c\/li\u003e\n\u003c\/ul\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 camera sensor size is the ODK10 designed for?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Orion Optics UK ODK10 is engineered to fully illuminate a \u003cstrong\u003e50mm image circle\u003c\/strong\u003e. This makes it ideal for cameras with full-frame (36x24mm) sensors and other large-format astronomy cameras, ensuring sharp stars and no vignetting across the entire field.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the ODK10's carbon fibre tube benefit astrophotography?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe carbon fibre sandwich tube has a near-zero coefficient of thermal expansion. This is a critical feature for long-exposure imaging, as it prevents the telescope's focus from shifting due to temperature changes throughout the night. This thermal stability means you spend less time refocusing and more time imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the 12kg weight of the ODK10 manageable for a mid-range mount?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. At approximately \u003cstrong\u003e12kg\u003c\/strong\u003e, the ODK10 optical tube is well within the payload capacity of mid-range equatorial mounts, such as those in the Sky-Watcher EQ6-R or Celestron CGX class, especially when used for imaging. Its short \u003cstrong\u003e530mm tube length\u003c\/strong\u003e also results in a lower moment arm, making it easier for the mount to guide accurately.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the 213mm back focus on the ODK10 allow me to do?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe generous \u003cstrong\u003e213mm of back focus\u003c\/strong\u003e provides extensive flexibility for building your imaging train. It allows you to easily incorporate multiple accessories between the focuser and the camera, such as:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eOff-Axis Guiders (OAGs)\u003c\/li\u003e\n\u003cli\u003eLarge filter wheels (e.g., 7-position 2\" carousels)\u003c\/li\u003e\n\u003cli\u003eAdaptive optics units\u003c\/li\u003e\n\u003cli\u003eCamera rotators\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the ODK10 perform on the Andromeda Galaxy (M31) with a full-frame camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ODK10 is an excellent choice for a target like the Andromeda Galaxy (M31). The \u003cstrong\u003e1700mm focal length\u003c\/strong\u003e provides enough image scale to resolve intricate dust lanes and star-forming regions in the spiral arms, while the \u003cstrong\u003e50mm flat field\u003c\/strong\u003e ensures that the entire galaxy and its satellite companions, M32 and M110, are framed with pinpoint stars from edge to edge on a full-frame sensor.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the ODK10 for high-resolution imaging of Jupiter?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. While designed as a deep-sky astrograph, the \u003cstrong\u003e250mm aperture\u003c\/strong\u003e of the ODK10 provides significant resolving power for planetary imaging. When paired with a high-quality Barlow lens (e.g., 2x or 3x) and a high-frame-rate planetary camera, the \u003cstrong\u003e1700mm focal length\u003c\/strong\u003e can be effectively increased to resolve fine details like the Great Red Spot, cloud bands, and festoons on Jupiter.\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\u003eCorrected Dall-Kirkham (ODK)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Mirror Diameter\u003c\/td\u003e\n\u003ctd\u003e250mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e1700mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/6.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrected Field Size\u003c\/td\u003e\n\u003ctd\u003e50mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpot Size (On-Axis)\u003c\/td\u003e\n\u003ctd\u003e3.5μm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpot Size (Field Edge)\u003c\/td\u003e\n\u003ctd\u003e6.2μm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e213mm (from rear of mirror cell, ±1mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e3\" Crayford with 10:1 reduction\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrector\u003c\/td\u003e\n\u003ctd\u003eMulti-coated 3 lens system\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Mirror Size\u003c\/td\u003e\n\u003ctd\u003e96mm\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\u003e530mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Diameter\u003c\/td\u003e\n\u003ctd\u003e300mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Weight\u003c\/td\u003e\n\u003ctd\u003eapprox. 12kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMirror Cell\u003c\/td\u003e\n\u003ctd\u003eHoneycomb CNC machined aluminium\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCooling System\u003c\/td\u003e\n\u003ctd\u003e3 controllable fans (heaters optional)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAttachment\u003c\/td\u003e\n\u003ctd\u003eCNC machined aluminium dovetail with supports\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\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":52942364967197,"sku":"OOUK-ODK10-OPTICAL-TUBE-ASSEMBLY","price":8334.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/OrionOpticsUK-ODK10-Optical-Tube-Assembly-1_808c12cc-b42b-4e31-ae8d-fe1ed81ca9ac.jpg?v=1789606889"},{"product_id":"orion-optics-uk-odk12-optical-tube-assembly","title":"Orion Optics UK ODK12 Optical Tube Assembly","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e300mm (12\") Optimised Dall-Kirkham Optics\u003c\/li\u003e\n\u003cli\u003e2040mm Focal Length at a fast f\/6.8 Focal Ratio\u003c\/li\u003e\n\u003cli\u003eCovers a greater than 52mm flat imaging circle\u003c\/li\u003e\n\u003cli\u003eDelivers 1.8µm on-axis spot sizes\u003c\/li\u003e\n\u003cli\u003eGenerous 218mm of back focal distance\u003c\/li\u003e\n\u003cli\u003eThermally stable carbon fibre sandwich tube construction\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 ODK12 Optical Tube Assembly\u003c\/h2\u003e\n\u003cp\u003eThe Orion Optics UK ODK12 is an astrograph engineered for large-format imaging, combining a 300mm primary mirror and a 2040mm focal length into a fast f\/6.8 system. Its integrated multi-coated 3-lens corrector produces a flat field greater than 52mm in diameter, delivering pinpoint stars with a spot size of just 1.8µm on-axis. The entire optical system is housed in a 625mm long carbon fibre sandwich tube that weighs approximately 19kg, ensuring thermal stability for critical 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\u003eODK Astrograph: 52mm Flat Field with 1.8µm Stars\u003c\/h3\u003e\n\u003cp\u003eThe Optimised Dall-Kirkham (ODK) design is built from the ground up for astrophotography. The ODK12 uses a 300mm primary mirror and a matched 120mm secondary, with a built-in 3-lens corrector group to eliminate off-axis coma and field curvature. This results in a corrected image circle larger than 52mm, capable of illuminating the largest commercially available astronomy camera sensors without vignetting or distortion.\u003c\/p\u003e\n\u003cp\u003eThe optical correction delivers incredibly tight stars across this massive field. On-axis spot sizes are a mere 1.8µm, and even at the extreme edge of the field, stars remain compact at 5.6µm. This level of correction ensures that you are capturing all the resolution the 300mm aperture can provide, making the ODK12 a premier instrument for high-resolution mosaics and large-field imaging of nebulae and galaxy clusters.\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 Fiber Tube \u0026amp; Active Cooling at 19kg\u003c\/h3\u003e\n\u003cp\u003eTo maintain focus stability during temperature drops, the ODK12 features a carbon fibre sandwich tube. This material has virtually zero thermal expansion, preventing the 2040mm focal plane from shifting during long exposures or throughout an imaging session. The tube's open design and short 625mm length promote rapid thermal acclimation.\u003c\/p\u003e\n\u003cp\u003eThis process is accelerated by three controllable cooling fans mounted behind the honeycomb CNC-machined primary mirror cell. This active cooling system quickly brings the 300mm mirror to ambient temperature, minimizing tube currents and ensuring the sharpest possible images from the moment you begin observing. At approximately 19kg, the OTA is manageable for observatory-class mounts rated for higher payloads.\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\u003e218mm Back Focus with a 3\" Crayford Focuser\u003c\/h3\u003e\n\u003cp\u003eA critical feature for serious imagers is ample back focus, and the ODK12 provides an exceptionally long 218mm of working distance from the rear of the mirror cell. This generous space allows you to assemble a complete imaging train with any combination of accessories—including off-axis guiders, large filter wheels, rotators, and adaptive optics—without concern for reaching focus.\u003c\/p\u003e\n\u003cp\u003eFocusing is controlled by a robust 3\" Crayford focuser with a 10:1 dual-speed reduction mechanism for precise adjustments. This heavy-duty focuser is designed to carry the weight of modern large-format cameras and accessory stacks without flexure or slippage, ensuring your focal plane remains locked and perfectly orthogonal to the optical axis.\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\u003eODK12 vs. 12\" Ritchey-Chrétien: Collimation and Correction\u003c\/h3\u003e\n\u003cp\u003eThe ODK12 is often compared to Ritchey-Chrétien (RC) astrographs of similar aperture. While RCs are renowned for their corrected fields, they have a key disadvantage.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eRC Advantage:\u003c\/strong\u003e Ritchey-Chrétien telescopes typically feature longer focal ratios (f\/8 or slower), which can provide more image scale for smaller targets without the need for Barlow lenses.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eODK12 Advantage:\u003c\/strong\u003e The ODK is significantly easier to collimate. Unlike an RC, which requires precise alignment of both the primary and secondary mirrors, the ODK's primary mirror is fixed. Collimation is achieved by adjusting the secondary mirror only, a much simpler and more stable process. Furthermore, the ODK's 3-lens corrector is an integrated part of the design, whereas many RCs require an additional, separate corrector to achieve a fully flat field.\u003c\/li\u003e\n\u003c\/ul\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 ODK12 OTA?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith a tube weight of approximately \u003cstrong\u003e19kg (42 lbs)\u003c\/strong\u003e, the ODK12 requires a robust, observatory-grade equatorial mount. For imaging, you should select a mount with a payload capacity of at least 60-70 lbs to comfortably handle the OTA plus the additional weight of your camera, guider, and accessories.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhich cameras are best suited for the ODK12's 52mm image circle?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ODK12's greater than \u003cstrong\u003e52mm flat field\u003c\/strong\u003e is designed for cameras with large, full-frame (36x24mm) or larger sensors. Cameras like the ZWO ASI6200, QHY600, or models with the KAF-16803 sensor will be fully illuminated, allowing you to capture vast fields of view, such as the entire Andromeda Galaxy (M31) and its companions in a single frame.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the ODK12's f\/6.8 focal ratio benefit deep-sky imaging?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003ef\/6.8\u003c\/strong\u003e focal ratio is a sweet spot for deep-sky imaging. It is fast enough to collect significant signal on faint nebulae and galaxies in shorter sub-exposures compared to slower f\/8 or f\/10 systems. At the same time, its \u003cstrong\u003e2040mm focal length\u003c\/strong\u003e provides enough image scale to resolve fine details in targets like the Whirlpool Galaxy (M51) or planetary nebulae.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the ODK12's 218mm back focal distance allow me to do?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e218mm back focal distance\u003c\/strong\u003e provides enormous flexibility for building your imaging train. It ensures you can fit a full stack of accessories, such as an off-axis guider, a large 3\" filter wheel, a camera rotator, and your camera, and still easily reach focus. This is a critical feature that many other astrographs lack.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs collimating the ODK12 difficult?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo, the ODK12 is designed for straightforward collimation. Unlike Ritchey-Chrétien designs that require careful alignment of both mirrors, the ODK's primary mirror is fixed. You only need to adjust the secondary mirror, which is a much simpler and more stable procedure, making it easier to maintain perfect optical alignment.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill I experience focus shift with the ODK12's carbon fiber tube?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003ecarbon fibre sandwich\u003c\/strong\u003e tube material is specifically chosen for its near-zero coefficient of thermal expansion. This means that as the ambient temperature changes during an imaging session, the \u003cstrong\u003e625mm\u003c\/strong\u003e tube will not shrink or expand, keeping the focal plane stable and eliminating the need for constant refocusing.\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\u003ePrimary Mirror Diameter\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\u003e2040mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/6.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrected Field Size\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;52mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpot Size (On-Axis)\u003c\/td\u003e\n\u003ctd\u003e1.8µm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpot Size (Field Edge)\u003c\/td\u003e\n\u003ctd\u003e5.6µm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Mirror Size\u003c\/td\u003e\n\u003ctd\u003e120mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focal Distance\u003c\/td\u003e\n\u003ctd\u003e218mm (from rear of mirror cell)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e3\" Crayford with 10:1 reduction\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrector Design\u003c\/td\u003e\n\u003ctd\u003eMulti-coated 3 lens\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\u003e625mm\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 Weight\u003c\/td\u003e\n\u003ctd\u003eapprox. 19kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMirror Cell\u003c\/td\u003e\n\u003ctd\u003eHoneycomb CNC machined aluminium\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCooling System\u003c\/td\u003e\n\u003ctd\u003e3 controllable fans\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAttachment\u003c\/td\u003e\n\u003ctd\u003eCNC machined aluminium dovetail with supports\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\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":52942365131037,"sku":"OOUK-ODK12-OPTICAL-TUBE-ASSEMBLY","price":13321.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/OrionOpticsUK-ODK12-Optical-Tube-Assembly-1_99c581f4-5562-4d1c-8b5f-39440e50ce50.jpg?v=1789606897"},{"product_id":"orion-optics-uk-odk14-optical-tube-assembly","title":"Orion Optics UK ODK14 Optical Tube Assembly","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrimary Mirror Diameter:\u003c\/strong\u003e 350mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFocal Ratio:\u003c\/strong\u003e f\/6.8\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCorrected Image Circle:\u003c\/strong\u003e \u0026gt;52mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTube Material:\u003c\/strong\u003e Carbon Fibre Sandwich\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBack Focus:\u003c\/strong\u003e 210mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTube Weight:\u003c\/strong\u003e approx. 26kg\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 ODK14 Optical Tube Assembly\u003c\/h2\u003e\n\u003cp\u003eThe Orion Optics UK ODK14 is an imaging instrument designed for large-format sensors, combining a 350mm primary mirror and a fast f\/6.8 focal ratio to capture deep-sky objects with exceptional detail. Its integrated three-lens corrector delivers a flat field greater than 52mm in diameter, producing round stars with a spot size of just 5.6µm at the edge of the field. The generous 210mm of back focus and a robust 3\" Crayford focuser accommodate complex imaging trains, while the 720mm carbon fiber tube maintains thermal stability across long exposures.\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 350mm f\/6.8 Astrograph with a \u0026gt;52mm Flat Field\u003c\/h3\u003e\n\u003cp\u003eThe core of the ODK14 is its Optimized Dall-Kirkham optical design, engineered specifically for astrophotography. The 350mm primary mirror gathers significant light, while the 2380mm focal length provides the image scale needed for high-resolution views of galaxies and nebulae. Unlike standard reflectors, the ODK14 incorporates a permanent three-lens corrector, which creates a diffraction-limited, color-corrected field of over 52mm—large enough to serve medium-format CCDs and full-frame CMOS sensors without vignetting or distortion.\u003c\/p\u003e\n\u003cp\u003eThis optical correction results in remarkably tight stars across the entire frame. On-axis, stars are focused to a spot size of just 2.1µm, expanding to only 5.6µm at the extreme edge of the field. This ensures that whether you are imaging the core of the Hercules Cluster (M13) or the faint outer arms of the Triangulum Galaxy (M33), every star is a pinpoint.\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\u003e400mm Carbon Sandwich Tube and CNC Cell\u003c\/h3\u003e\n\u003cp\u003eTo maintain optical precision, the ODK14 is built around a carbon fiber sandwich tube with a 400mm diameter. This material provides extreme rigidity at a manageable weight of approximately 26kg and, more importantly, has a near-zero coefficient of thermal expansion. This prevents the 2380mm focal plane from shifting as temperatures drop overnight, eliminating the need for constant refocusing during an imaging session.\u003c\/p\u003e\n\u003cp\u003eThe 350mm primary mirror is supported by a honeycomb, CNC-machined aluminum cell that prevents flexure at any orientation. To achieve rapid thermal equilibrium, three controllable fans are positioned behind the mirror cell, quickly cooling the primary mirror to ambient temperature for sharp, stable views. This open-tube design cools down significantly faster than a comparable closed-tube Schmidt-Cassegrain.\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\u003e210mm of Back Focus and a 3\" Crayford Focuser\u003c\/h3\u003e\n\u003cp\u003eThe ODK14 is designed to integrate seamlessly into a modern imaging setup. It provides a massive 210mm of back focal distance, measured from the rear of the mirror cell. This generous spacing allows you to easily install any combination of accessories in the optical train, including off-axis guiders, large filter wheels, rotators, and adaptive optics units, without concern for reaching focus.\u003c\/p\u003e\n\u003cp\u003eFocusing is controlled by a heavy-duty 3\" Crayford focuser with a 10:1 reduction for precise fine adjustments. This focuser is capable of supporting heavy, large-format camera packages without slipping or tilting, ensuring the sensor remains perfectly orthogonal to the light path. The entire assembly is mounted using a CNC-machined aluminum dovetail system for a secure connection to your equatorial mount.\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\u003eODK14 vs. Ritchey-Chrétien: Corrected Field and Collimation\u003c\/h3\u003e\n\u003cp\u003eThe primary competitor for an astrograph like the ODK14 is a traditional Ritchey-Chrétien (RC) telescope. While RCs are known for their coma-free fields, they typically require a separate, costly field flattener to correct for significant off-axis astigmatism and produce a truly flat field for imaging.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eIntegrated Correction:\u003c\/strong\u003e The ODK14's built-in three-lens corrector delivers a flat, \u0026gt;52mm corrected field out of the box. An RC of similar aperture often requires an additional corrector, adding complexity and cost to the imaging train.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpot Size:\u003c\/strong\u003e Thanks to its corrective elements, the ODK14 maintains tight, round stars to the edge of the field, with a specified spot size of only 5.6µm. This is often superior to what an RC with a generic flattener can achieve.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCollimation:\u003c\/strong\u003e Ritchey-Chrétien telescopes are notoriously sensitive to collimation, requiring precise alignment of both the primary and secondary hyperbolic mirrors. The ODK design is generally more forgiving to align, allowing you to spend more time imaging and less time adjusting optics.\u003c\/li\u003e\n\u003c\/ul\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 kind of mount is required for the ODK14 OTA?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith a tube weight of approximately \u003cstrong\u003e26kg (57 lbs)\u003c\/strong\u003e, the ODK14 requires a high-capacity equatorial mount. For reliable imaging, you should choose a mount with a rated instrument capacity of at least 40kg (90 lbs) to comfortably handle the OTA plus a full imaging train. Mounts in the class of a 10Micron GM2000, Software Bisque Paramount ME II, or Astro-Physics 1100GTO are appropriate.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the ODK14's 2380mm focal length perform on small galaxies like the Whirlpool Galaxy (M51)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe 2380mm focal length is ideal for targets like M51, especially when paired with modern CMOS cameras with small pixels (e.g., 2.9µm to 3.76µm). The combination provides an excellent image scale for resolving fine details like individual HII regions, dust lanes, and the tidal bridge connecting M51 to its companion galaxy, NGC 5195.\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 ODK14's 210mm back focus?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e210mm back focus\u003c\/strong\u003e distance provides ample room to install a complete, modern imaging train. This allows you to use accessories such as an off-axis guider (OAG), a large-format filter wheel (for LRGB and narrowband filters), an electronic rotator, and your primary imaging camera without running out of focus travel. It eliminates the need for extenders and ensures maximum flexibility.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy does the ODK14 use a carbon fiber tube?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA carbon fiber sandwich tube offers two key advantages for high-resolution imaging. First, it has a \u003cstrong\u003enear-zero coefficient of thermal expansion\u003c\/strong\u003e, which prevents the telescope's focus from shifting as the ambient temperature changes during the night. Second, it has a very high stiffness-to-weight ratio, ensuring the optical elements remain perfectly aligned regardless of the telescope's orientation.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan the ODK14 be used for planetary imaging of Jupiter or Saturn?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, absolutely. The large \u003cstrong\u003e350mm aperture\u003c\/strong\u003e provides incredible resolving power, capable of revealing fine details in Jupiter's cloud bands, the Great Red Spot, and the Cassini Division in Saturn's rings. While the native f\/6.8 focal ratio is fast for planetary work, adding a 2.5x or 3x Barlow lens will increase the effective focal length to an ideal range for high-frame-rate planetary cameras.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the \u0026gt;52mm corrected field of the ODK14 mean for my camera choice?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e\u0026gt;52mm fully corrected image circle\u003c\/strong\u003e means the ODK14 can illuminate and provide sharp, pinpoint stars across the largest commercially available astronomy sensors. This includes:\n\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFull-Frame Sensors:\u003c\/strong\u003e (e.g., Sony IMX571, IMX455) which have a diagonal of ~43mm.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMedium-Format Sensors:\u003c\/strong\u003e (e.g., KAF-16803) which have a diagonal of 52.1mm.\u003c\/li\u003e\n\u003c\/ul\u003e\nYou can use any of these large sensors without worrying about vignetting or distorted stars in the corners of your images.\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\u003ePrimary Mirror Diameter\u003c\/td\u003e\n\u003ctd\u003e350mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e2380mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/6.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrected Field Size\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;52mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpot Size (On-Axis)\u003c\/td\u003e\n\u003ctd\u003e2.1µm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpot Size (Field Edge)\u003c\/td\u003e\n\u003ctd\u003e5.6µm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrector Design\u003c\/td\u003e\n\u003ctd\u003eMulti-coated 3 lens\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e210mm (from rear of mirror cell, ±1mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e3\" Crayford with 10:1 reduction\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\u003e720mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Diameter\u003c\/td\u003e\n\u003ctd\u003e400mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Weight\u003c\/td\u003e\n\u003ctd\u003eapprox. 26kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Mirror Size\u003c\/td\u003e\n\u003ctd\u003e136mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMirror Cell\u003c\/td\u003e\n\u003ctd\u003eHoneycomb CNC machined aluminium\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMirror \u0026amp; Tube Cooling\u003c\/td\u003e\n\u003ctd\u003e3 controllable fans (heaters optional)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAttachment Method\u003c\/td\u003e\n\u003ctd\u003eCNC machined aluminium dovetail with supports\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\"\u003eODK14 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\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":52942365425949,"sku":"OOUK-ODK14-OPTICAL-TUBE-ASSEMBLY","price":18116.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/OrionOpticsUK-ODK14-Optical-Tube-Assembly-1_dab33d06-5f04-4966-84bc-ef40b7061d52.jpg?v=1789606905"},{"product_id":"orion-optics-uk-odk16-optical-tube-assembly","title":"Orion Optics UK ODK16 Optical Tube Assembly","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e400mm (16\") Primary Mirror Diameter\u003c\/li\u003e\n\u003cli\u003e2720mm Focal Length at f\/6.8\u003c\/li\u003e\n\u003cli\u003eCorrected Dall-Kirkham Optical Design\u003c\/li\u003e\n\u003cli\u003e\u0026gt;52mm Flat Field Image Circle\u003c\/li\u003e\n\u003cli\u003eCarbon Fibre Sandwich Tube Construction\u003c\/li\u003e\n\u003cli\u003e216mm of Back Focal Distance\u003c\/li\u003e\n\u003cli\u003e3\" Crayford Focuser with 10:1 Reduction\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 ODK16 Optical Tube Assembly\u003c\/h2\u003e\n\u003cp\u003eThe Orion Optics UK ODK16 combines a massive 400mm primary mirror with a fast f\/6.8 focal ratio to create a formidable deep-sky imaging platform. Its integrated 3-lens corrector delivers a fully flat field greater than 52mm in diameter, producing pinpoint stars from a 2.4µm on-axis spot size out to just 6.0µm at the edge of the field. With a focal length of 2720mm and a thermally stable carbon fibre tube, the ODK16 is engineered to resolve fine detail on distant galaxies and planetary surfaces with professional-grade optical accuracy.\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\u003e400mm f\/6.8 Optics: A \u0026gt;52mm Flat Field for Large Format Sensors\u003c\/h3\u003e\n\u003cp\u003eThe heart of the ODK16 is its corrected Dall-Kirkham optical system. The 400mm primary mirror gathers immense light, while the f\/6.8 focal ratio allows for shorter exposure times on faint nebulae compared to slower designs. A factory-matched, multi-coated 3-lens corrector is permanently integrated into the optical path, eliminating the need for third-party flatteners and ensuring the system performs to its full potential.\u003c\/p\u003e\n\u003cp\u003eThis design produces a corrected image circle greater than 52mm, fully illuminating the largest full-frame CMOS and CCD sensors without vignetting or field curvature. With spot sizes as small as 2.4µm, you can leverage the resolution of modern high-pixel-density cameras to capture incredibly sharp, detailed images across the entire frame.\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\u003eZero-Expansion Carbon Tube: Thermal Stability Across a 835mm Tube\u003c\/h3\u003e\n\u003cp\u003eTo maintain precise focus during temperature drops, the ODK16's 835mm tube is constructed from a carbon fibre sandwich material. This advanced composite has virtually zero thermal expansion, preventing the focal plane from shifting during long imaging sessions or throughout the night. The result is consistently sharp stars without the need for constant refocusing.\u003c\/p\u003e\n\u003cp\u003eThe open-tube design, combined with three controllable fans behind the honeycomb CNC-machined primary mirror cell, ensures rapid thermal acclimation. This active cooling system quickly brings the 400mm mirror to ambient temperature, minimizing tube currents and delivering stable, high-contrast views sooner.\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 Integration: 216mm of Back Focus and a 3\" Crayford\u003c\/h3\u003e\n\u003cp\u003eThe ODK16 is built from the ground up for serious astrophotography. It provides a generous 216mm of back focal distance measured from the rear of the mirror cell, offering ample room for complex imaging trains. You can easily accommodate off-axis guiders, large filter wheels, rotators, and adaptive optics systems without concern for reaching focus.\u003c\/p\u003e\n\u003cp\u003eFocusing is managed by a robust 3\" Crayford focuser, featuring 10:1 fine reduction for critical adjustments. This large-aperture focuser provides a rigid, flexure-free connection point for heavy camera packages, ensuring the optical axis remains perfectly aligned throughout your exposure.\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\u003eODK16 vs. Ritchey-Chrétien: The Advantage of an Integrated Corrector\u003c\/h3\u003e\n\u003cp\u003eWhile Ritchey-Chrétien (RC) telescopes are known for their coma-free fields, they typically operate at f\/8 or slower and require a separate, often expensive, field flattener or reducer to produce sharp stars on large sensors. The ODK16's primary advantage is its fully integrated, optimized optical system.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBuilt-in Correction:\u003c\/strong\u003e The ODK16's 3-lens corrector is designed as part of the optical train, not an add-on. This guarantees a \u0026gt;52mm flat field out of the box, with performance optimized for its native f\/6.8 focal ratio.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFaster Imaging:\u003c\/strong\u003e At f\/6.8, the ODK16 requires significantly less exposure time to reach the same signal-to-noise ratio as a comparable f\/8 RC, allowing you to gather more data in a single night.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo Spacing guesswork:\u003c\/strong\u003e With an integrated corrector, you avoid the trial-and-error of finding the perfect corrector-to-sensor spacing that is often required with third-party accessories on an RC.\u003c\/li\u003e\n\u003c\/ul\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 camera sensors can the ODK16's \u0026gt;52mm image circle cover?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ODK16's image circle of over 52mm is large enough to fully illuminate and correct for full-frame sensors (36x24mm, 43mm diagonal) and even larger medium-format sensors. This makes it an ideal match for popular full-frame astronomy cameras, ensuring you have pinpoint stars and no vignetting across the entire field.\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 ODK16's 36kg weight?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith an approximate tube weight of 36kg, plus the added weight of a large camera, guider, and accessories, the ODK16 requires a high-capacity equatorial mount. You should look for a mount in the 100 lb (45 kg) payload class or higher to ensure stable, precise tracking for long-exposure astrophotography.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the ODK16's carbon fibre tube benefit imaging?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe carbon fibre sandwich construction has a near-zero coefficient of thermal expansion. As temperatures change overnight, a metal tube will shrink, causing the focal point to shift and requiring you to refocus. The ODK16's tube holds focus rigidly, keeping your images sharp throughout long automated imaging sequences.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the 216mm back focus on the ODK16 allow me to install?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe 216mm of back focus is extremely generous and provides ample space for a complete imaging train. You can easily fit components such as:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eAn off-axis guider (OAG)\u003c\/li\u003e\n\u003cli\u003eA large-format filter wheel (e.g., 5-position or 7-position 2\")\u003c\/li\u003e\n\u003cli\u003eAn electronic rotator\u003c\/li\u003e\n\u003cli\u003eAn adaptive optics unit\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the ODK16 perform on small targets like the Dumbbell Nebula (M27)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith a 2720mm focal length, the ODK16 provides significant image scale, making it perfect for resolving detail in smaller deep-sky objects. M27 and other planetary nebulae or smaller galaxies will be framed beautifully, allowing you to capture intricate structural details that are inaccessible to shorter focal length instruments.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the ODK16's f\/6.8 focal ratio a good compromise for different targets?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, f\/6.8 is an excellent \"all-around\" focal ratio for a large imaging instrument. It is fast enough to capture faint, extended objects like the Veil Nebula (NGC 6960) in reasonable time, while the 2720mm focal length still provides the high resolution needed for detailed views of Jupiter's cloud bands or Saturn's 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\u003ePrimary Mirror Diameter\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\u003e2720mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/6.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focal Distance\u003c\/td\u003e\n\u003ctd\u003e216mm (from rear of mirror cell, ±1mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Weight\u003c\/td\u003e\n\u003ctd\u003eapprox. 36kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Length\u003c\/td\u003e\n\u003ctd\u003e835mm\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 Material\u003c\/td\u003e\n\u003ctd\u003eCarbon fibre sandwich\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Mirror Size\u003c\/td\u003e\n\u003ctd\u003e152mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrector Design\u003c\/td\u003e\n\u003ctd\u003eMulti-coated 3 lens\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrected Flat Field\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;52mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpot Size (On-Axis)\u003c\/td\u003e\n\u003ctd\u003e2.4µm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpot Size (Field Edge)\u003c\/td\u003e\n\u003ctd\u003e6.0µm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e3\" Crayford with 10:1 reduction\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMirror Cell\u003c\/td\u003e\n\u003ctd\u003eHoneycomb CNC machined aluminium\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCooling System\u003c\/td\u003e\n\u003ctd\u003e3 controllable fans\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAttachment Method\u003c\/td\u003e\n\u003ctd\u003eCNC machined aluminium dovetail with supports\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\"\u003eODK16 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\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eNo product-specific manual or software is available for the Orion Optics UK ODK16 Optical Tube Assembly at this time.\u003c\/p\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":52942365524253,"sku":"OOUK-ODK16-OPTICAL-TUBE-ASSEMBLY","price":25212.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Logo_dfa4a989-71b5-41e6-9a89-14f8b8b82677.jpg?v=1789606914"},{"product_id":"orion-optics-uk-odk10tr-optical-tube-assembly","title":"Orion Optics UK ODK10Tr Truss Optical Tube Assembly","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e250mm (10-inch) Optimized Dall-Kirkham optics\u003c\/li\u003e\n\u003cli\u003e1700mm focal length at a native f\/6.8 focal ratio\u003c\/li\u003e\n\u003cli\u003e50mm fully corrected, flat image circle for large sensors\u003c\/li\u003e\n\u003cli\u003e3.5μm on-axis spot size for sharp stars\u003c\/li\u003e\n\u003cli\u003eCarbon fiber truss tube construction weighing only 12kg\u003c\/li\u003e\n\u003cli\u003e3-inch Crayford focuser with 10:1 fine 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\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 ODK10Tr Truss Optical Tube Assembly\u003c\/h2\u003e\n\u003cp\u003eThe Orion Optics UK ODK10Tr is an imaging instrument designed for uncompromising optical clarity, delivering a 50mm flat field from its 250mm f\/6.8 corrected Dall-Kirkham optics. With a focal length of 1700mm, it achieves pinpoint stars measuring just 3.5μm on-axis and 6.2μm at the edge of the field, ensuring full use of modern high-resolution sensors. Its carbon fiber truss construction keeps the weight to approximately 12kg, providing exceptional rigidity and thermal stability for serious 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\u003eCorrected Dall-Kirkham: 50mm Flat Field with 3.5μm Spot Sizes\u003c\/h3\u003e\n\u003cp\u003eThe heart of the ODK10Tr is its optical system, which pairs an elliptical primary mirror with a spherical secondary and a dedicated 3-lens corrector. This design produces a 50mm diameter, fully illuminated and corrected image circle, free of coma and field curvature. You can confidently use full-frame (35mm format) sensors and even larger medium-format chips without vignetting or distorted stars at the corners.\u003c\/p\u003e\n\u003cp\u003eThe optical correction delivers incredibly tight star images, with a measured spot size of only 3.5μm at the center of the field and 6.2μm at the very edge. This level of correction ensures that the telescope's resolution, not the optics, is the limiting factor, resolving fine detail in galaxies and nebulae even with small-pixel CMOS cameras.\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 Fiber Truss: 12kg of Rigid, Stable Construction\u003c\/h3\u003e\n\u003cp\u003eThe ODK10Tr's open truss structure, built from a carbon fiber sandwich material, provides a superior stiffness-to-weight ratio. At just 12kg, this 10-inch astrograph is manageable for a wide range of equatorial mounts while remaining exceptionally rigid to prevent flexure as it moves across the sky. Carbon fiber's low thermal expansion coefficient also ensures the 1700mm focal length remains stable during temperature drops, minimizing focus shift throughout an imaging session.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eActive Cooling:\u003c\/strong\u003e Three integrated, controllable fans are mounted behind the primary mirror to accelerate thermal acclimation, allowing you to start imaging faster.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCNC Machined Components:\u003c\/strong\u003e Key mechanical parts, including the honeycomb mirror cell and dovetail plate supports, are CNC machined from aluminum for precise, repeatable alignment and durability.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStray Light Control:\u003c\/strong\u003e While the open truss design promotes rapid cooling, it is susceptible to stray light. Using a simple fabric shroud (not included) is recommended to maximize image contrast, especially from light-polluted locations.\u003c\/li\u003e\n\u003c\/ul\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\" Focuser and 213mm Back Focus\u003c\/h3\u003e\n\u003cp\u003eEngineered for demanding imaging setups, the ODK10Tr features a robust 3\" Crayford focuser with a 10:1 reduction ratio for precise fine adjustments. The large-diameter drawtube eliminates vignetting with large sensors and can support heavy camera packages without slipping or tilting. With a generous 213mm of back focus measured from the rear of the mirror cell, you have ample room to install complex imaging trains, including off-axis guiders, large filter wheels, and camera rotators, without concern for reaching focus.\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\u003eODK10Tr vs. Ritchey-Chrétien: Collimation, Field Correction, and Spot Size\u003c\/h3\u003e\n\u003cp\u003eFor imagers seeking a flat-field instrument, the main alternative to an ODK is a Ritchey-Chrétien (RC). While both are excellent designs, the ODK presents several practical advantages.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompetitor's Advantage (RC):\u003c\/strong\u003e A pure RC design is naturally free from coma, an optical aberration that elongates stars away from the center. However, it suffers from significant astigmatism and field curvature, requiring a separate corrector for serious imaging.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eODK10Tr Advantage:\u003c\/strong\u003e The ODK's integrated 3-lens corrector fully addresses coma, astigmatism, and field curvature across its 50mm image circle. More importantly, the ODK's spherical secondary mirror makes collimation far more forgiving than the hyperbolic secondary of an RC, which requires extremely precise alignment. For most users, the ODK delivers superior edge-of-field star shapes and is significantly easier to maintain in perfect adjustment.\u003c\/li\u003e\n\u003c\/ul\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 sensors are a good match for the ODK10Tr's 50mm image circle?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe 50mm fully corrected image circle is ideal for full-frame sensors (e.g., Sony IMX455, IMX571 in APS-C format) and even some medium-format CCD or CMOS chips. You can use any sensor up to a 50mm diagonal without experiencing significant vignetting or distorted stars at the corners.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I use the 213mm of back focus on the ODK10Tr?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e213mm back focus\u003c\/strong\u003e is measured from the rear plate of the mirror cell. You will need to use extension tubes between the focuser and your camera to place the sensor at the correct focal plane. This generous distance ensures you can fit any combination of accessories like an off-axis guider, filter wheel, and adaptive optics unit into your imaging train.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow difficult is it to collimate the ODK10Tr compared to an RC?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ODK10Tr is significantly easier to collimate. Its spherical secondary mirror is much less sensitive to tilt errors than the hyperbolic secondary of a Ritchey-Chrétien. This makes achieving and maintaining perfect optical alignment a much simpler process, which is a major practical advantage for field use.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I need a shroud for the ODK10Tr's truss design?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhile not strictly required, a light shroud is highly recommended. The open truss design is excellent for thermal management but can allow stray light to hit the focal plane, reducing contrast. A shroud also helps protect the mirrors from dew and dust. It is an essential accessory for getting the best possible performance from the telescope.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the ODK10Tr perform on a large target like the Andromeda Galaxy (M31) with a full-frame camera?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ODK10Tr is exceptionally well-suited for this scenario. Its 1700mm focal length provides the ideal image scale for capturing detail in the galaxy's dust lanes and core, while the 50mm flat image circle allows a full-frame sensor to capture the full expanse of M31 in a single frame with sharp stars from edge to edge.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the ODK10Tr's f\/6.8 focal ratio suitable for imaging smaller planetary nebulae like the Ring Nebula (M57)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The \u003cstrong\u003ef\/6.8 focal ratio\u003c\/strong\u003e and \u003cstrong\u003e1700mm focal length\u003c\/strong\u003e provide excellent image scale for resolving details in smaller targets like the Ring Nebula (M57) or the Dumbbell Nebula (M27). The high optical quality and small spot sizes will allow you to capture fine structural details within these objects, especially when paired with a camera that has small pixels.\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\u003eOptimized Dall-Kirkham (ODK) with 3-Lens Corrector\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Mirror Diameter\u003c\/td\u003e\n\u003ctd\u003e250mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e1700mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/6.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrected Field Size\u003c\/td\u003e\n\u003ctd\u003e50mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpot Size (On-Axis)\u003c\/td\u003e\n\u003ctd\u003e3.5μm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpot Size (Field Edge)\u003c\/td\u003e\n\u003ctd\u003e6.2μm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Mirror Size\u003c\/td\u003e\n\u003ctd\u003e96mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e213mm (from rear of mirror cell)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e3\" Crayford with 10:1 Reduction\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Material\u003c\/td\u003e\n\u003ctd\u003eCarbon Fibre Sandwich Truss\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Length\u003c\/td\u003e\n\u003ctd\u003e475mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Diameter\u003c\/td\u003e\n\u003ctd\u003e300mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Weight\u003c\/td\u003e\n\u003ctd\u003eapprox. 12kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMirror Cell\u003c\/td\u003e\n\u003ctd\u003eHoneycomb CNC Machined Aluminium\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMirror Cooling\u003c\/td\u003e\n\u003ctd\u003e3 controllable fans\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAttachment\u003c\/td\u003e\n\u003ctd\u003eCNC Machined Aluminium 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\"\u003eODK10Tr Truss 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\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":52942365688093,"sku":"OOUK-ODK10TR-OPTICAL-TUBE-ASSEMBLY","price":11316.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Logo_e23803b0-3de1-43d0-a3a8-278a610b3ea1.jpg?v=1789606922"},{"product_id":"orion-optics-uk-odk12tr-optical-tube-assembly","title":"Orion Optics UK ODK12Tr Truss Optical Tube Assembly","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e300mm (12\") Optimized Dall-Kirkham Astrograph\u003c\/li\u003e\n\u003cli\u003e2040mm Focal Length (f\/6.8)\u003c\/li\u003e\n\u003cli\u003e\u0026gt;52mm Flat, Corrected Image Circle\u003c\/li\u003e\n\u003cli\u003e1.8µm On-Axis Spot Size\u003c\/li\u003e\n\u003cli\u003eCarbon Fiber Truss Tube Construction\u003c\/li\u003e\n\u003cli\u003e218mm of Back Focus\u003c\/li\u003e\n\u003cli\u003e3\" Crayford Focuser with 10:1 Reduction\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 ODK12Tr Truss Optical Tube Assembly\u003c\/h2\u003e\n\u003cp\u003eThe Orion Optics UK ODK12Tr Truss is a dedicated imaging platform built around a 300mm primary mirror with a 2040mm focal length. Its f\/6.8 corrected Dall-Kirkham design delivers incredibly small 1.8µm spot sizes on-axis and maintains a flat field greater than 52mm in diameter. The entire carbon fiber truss assembly weighs approximately 19kg and provides a generous 218mm of back focal distance for complex accessory stacks.\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\u003e300mm f\/6.8 Optics: 5.6µm Spots Across a \u0026gt;52mm Field\u003c\/h3\u003e\n\u003cp\u003eThe ODK12Tr's optical system is engineered for large-format sensors. The 300mm primary mirror operates at f\/6.8, providing enough image scale for detailed views of distant galaxies without demanding excessively long exposure times. A built-in, multi-coated 3-lens corrector flattens the field, delivering pinpoint stars with a spot size of just 5.6µm at the edge of a massive 52mm image circle—fully illuminating full-frame and larger sensors.\u003c\/p\u003e\n\u003cp\u003eThe 120mm secondary mirror provides this wide-field illumination, creating a 40% central obstruction by diameter. This is a necessary trade-off for edge-to-edge performance on large chips and has minimal impact on deep-sky imaging, where light grasp and field flatness are paramount.\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 Fiber Truss: A 19kg Platform for Stable Imaging\u003c\/h3\u003e\n\u003cp\u003eConstructed from a carbon fiber sandwich material, the ODK12Tr's open truss frame offers exceptional thermal and mechanical stability. Weighing approximately 19kg, the tube assembly is rigid enough to support heavy imaging loads without flexure. The carbon fiber's near-zero coefficient of thermal expansion means the 2040mm focal length remains constant as temperatures drop, preventing focus shift during long imaging sessions.\u003c\/p\u003e\n\u003cp\u003eThe open truss design allows the 300mm primary mirror to acclimate to ambient temperatures quickly, aided by three controllable fans integrated into the honeycomb CNC-machined mirror cell. This active thermal management ensures your images are sharp from the start of the night to the end.\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\u003e218mm Back Focus \u0026amp; 3\" Focuser: Ready for Any Imaging Train\u003c\/h3\u003e\n\u003cp\u003eThe ODK12Tr is designed to accommodate any modern imaging accessory. It provides 218mm of back focal distance measured from the rear of the mirror cell, offering ample room for off-axis guiders, filter wheels, rotators, and large-format cameras. You won't need to compromise on your ideal setup due to spacing constraints.\u003c\/p\u003e\n\u003cp\u003eTo carry this load, the OTA is equipped with a robust 3\" Crayford focuser featuring a 10:1 reduction for precise, repeatable fine adjustments. The large drawtube diameter prevents vignetting with large sensors and ensures your entire imaging train is held securely throughout the night.\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\u003eODK12Tr vs. Ritchey-Chrétien: Collimation and Field Correction\u003c\/h3\u003e\n\u003cp\u003eUnlike Ritchey-Chrétien (RC) telescopes that use two difficult-to-align hyperbolic mirrors, the Optimized Dall-Kirkham (ODK) design employs an elliptical primary and a spherical secondary. This makes collimation significantly more forgiving and stable, saving valuable clear-sky time.\u003c\/p\u003e\n\u003cp\u003eWhile a classic Dall-Kirkham suffers from off-axis coma, the ODK12Tr's integrated 3-lens corrector completely eliminates it, producing a wide, flat, coma-free field that rivals the best RCs. The result is an astrograph that combines the optical simplicity and collimation stability of the DK design with the professional, wide-field imaging results of a corrected RC.\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 sensor size can the ODK12Tr fully illuminate and correct?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ODK12Tr provides a fully corrected, flat field size of \u003cstrong\u003eover 52mm in diameter\u003c\/strong\u003e. This is large enough to cover full-frame (36x24mm) and even larger format astronomy sensors without significant vignetting or distortion at the corners.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the ODK12Tr's carbon fiber truss help with astrophotography?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe carbon fiber construction offers two key benefits. First, it has an extremely low coefficient of thermal expansion, which means the telescope's \u003cstrong\u003e2040mm focal length does not change\u003c\/strong\u003e as temperatures drop overnight, preventing focus shift. Second, the open truss design allows the primary mirror to cool down to ambient temperature much faster, aided by the \u003cstrong\u003ethree integrated cooling fans\u003c\/strong\u003e.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow would the ODK12Tr perform on a large target like the Andromeda Galaxy (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ODK12Tr is an excellent choice for M31. Its \u003cstrong\u003e2040mm focal length\u003c\/strong\u003e and \u003cstrong\u003e300mm aperture\u003c\/strong\u003e provide the necessary resolution to capture fine dust lanes and star-forming regions within the galaxy's spiral arms. The \u003cstrong\u003e\u0026gt;52mm corrected field\u003c\/strong\u003e allows you to frame a significant portion of the galaxy and its companions in a single shot with a large-format camera.\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 ODK12Tr's 218mm of back focus?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e218mm of back focus\u003c\/strong\u003e is exceptionally generous and provides critical flexibility for building your imaging train. It ensures you have enough space to install multiple accessories—such as an off-axis guider, a filter wheel, an adaptive optics unit, and a rotator—between the focuser and the camera sensor without running out of focus travel.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the ODK12Tr's f\/6.8 focal ratio good for imaging smaller targets like the Ring Nebula (M57)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the f\/6.8 focal ratio is a versatile sweet spot. For a target like M57, the \u003cstrong\u003e2040mm focal length\u003c\/strong\u003e yields a large enough image scale to clearly resolve the nebula's ring structure and the faint central star. The focal ratio is still fast enough to capture significant signal in reasonable sub-exposure times, making it efficient for both broadband and narrowband imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy choose the ODK12Tr over a comparable Ritchey-Chrétien astrograph?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe primary advantage of the ODK12Tr is its ease of collimation. Ritchey-Chrétien designs use two hyperbolic mirrors that are notoriously difficult to align perfectly. The ODK's elliptical primary and spherical secondary are far more tolerant, holding collimation better and being easier to adjust. With its integrated corrector, the ODK provides the flat, coma-free field of an RC without the collimation challenges.\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\u003eOptimized Dall-Kirkham (Corrected)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Mirror Diameter\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\u003e2040mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/6.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrected Field Size\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;52mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpot Size (On-Axis)\u003c\/td\u003e\n\u003ctd\u003e1.8µm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpot Size (Field Edge)\u003c\/td\u003e\n\u003ctd\u003e5.6µm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Mirror Size\u003c\/td\u003e\n\u003ctd\u003e120mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e3\" Crayford with 10:1 reduction\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e218mm (from rear of mirror cell)\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\u003e615mm\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 Weight\u003c\/td\u003e\n\u003ctd\u003eapprox. 19kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMirror Cell\u003c\/td\u003e\n\u003ctd\u003eHoneycomb CNC machined aluminium\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCooling System\u003c\/td\u003e\n\u003ctd\u003e3 controllable fans\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAttachment\u003c\/td\u003e\n\u003ctd\u003eCNC machined aluminium 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\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":52942365786397,"sku":"OOUK-ODK12TR-OPTICAL-TUBE-ASSEMBLY","price":16006.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Logo_4e6790da-dd7f-4ac3-a55a-cf0778c4f563.jpg?v=1789606931"},{"product_id":"orion-optics-uk-odk14tr-optical-tube-assembly","title":"Orion Optics UK ODK14Tr Truss Optical Tube Assembly","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e350mm (14\") Optimized Dall-Kirkham Optics\u003c\/li\u003e\n\u003cli\u003e2380mm Focal Length (f\/6.8)\u003c\/li\u003e\n\u003cli\u003e\u0026gt;52mm Fully Illuminated and Corrected Image Circle\u003c\/li\u003e\n\u003cli\u003e2.1µm On-Axis Spot Size\u003c\/li\u003e\n\u003cli\u003eCarbon Fibre Truss Tube Construction\u003c\/li\u003e\n\u003cli\u003e210mm of Back Focus\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 ODK14Tr Truss Optical Tube Assembly\u003c\/h2\u003e\n\u003cp\u003eThe Orion Optics UK ODK14Tr is an astrograph engineered for large-format imaging, combining a 350mm primary mirror with a fast f\/6.8 focal ratio to deliver a 2380mm focal length ideal for detailed views of deep-sky objects. Its Optimized Dall-Kirkham design employs a multi-coated 3-lens corrector to produce a flat field greater than 52mm in diameter, achieving pinpoint stars with spot sizes as small as 2.1μm on-axis. The open carbon fibre truss structure weighs approximately 26kg and is built for thermal stability, supported by three controllable fans for rapid mirror cooling.\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\u003eODK Optics: A 350mm f\/6.8 System with a \u0026gt;52mm Corrected Field\u003c\/h3\u003e\n\u003cp\u003eThe heart of the ODK14Tr is its Optimized Dall-Kirkham optical system, which pairs an ellipsoidal primary mirror with a spherical secondary. This configuration is inherently easier to figure to a high degree of smoothness than more complex aspheric designs. The system's native coma is fully addressed by a dedicated, multi-coated 3-lens corrector, resulting in a diffraction-limited, flat field across a massive \u0026gt;52mm image circle.\u003c\/p\u003e\n\u003cp\u003eThis optical design delivers incredibly sharp stars, with a measured spot size of just 2.1μm on-axis and 5.6μm at the edge of the field. This ensures that the telescope's resolution is not the limiting factor, even when paired with modern CMOS cameras that have very small pixels. The 350mm aperture gathers significant light, while the f\/6.8 focal ratio provides a balance of image scale and exposure speed suitable for imaging everything from distant galaxy clusters to faint nebulae.\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\u003eTruss Structure: Carbon Fibre Sandwich Construction at 26kg\u003c\/h3\u003e\n\u003cp\u003eThe ODK14Tr utilizes an open truss framework made from a carbon fibre sandwich material, a design choice that offers superior thermal performance and rigidity. Unlike a solid tube, the open design prevents the formation of tube currents and allows the optics to acclimate to ambient temperatures quickly. The carbon fibre construction minimizes focus shift caused by temperature changes, a critical factor for maintaining sharpness over long imaging sessions.\u003c\/p\u003e\n\u003cp\u003eDespite its large 400mm tube diameter, the OTA weighs approximately 26kg and has a compact length of 700mm, making it manageable for high-capacity observatory-class mounts. The primary mirror is housed in a honeycomb CNC machined aluminum cell, providing rigid support without inducing mechanical stress on the optics.\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\u003eThermal Control: Active Cooling with 3 Controllable Fans\u003c\/h3\u003e\n\u003cp\u003eAchieving thermal equilibrium is essential for high-resolution imaging, and the ODK14Tr addresses this directly with an integrated active cooling system. Three controllable fans are positioned behind the primary mirror to accelerate the cooling process, drawing air across the back of the 350mm mirror to bring it to ambient temperature rapidly.\u003c\/p\u003e\n\u003cp\u003eBy minimizing the temperature differential between the glass and the surrounding air, this system drastically reduces mirror seeing—the localized turbulence that can soften fine details. This allows you to start imaging sooner and maintain optimal optical performance throughout the night. For observers in dew-prone locations, optional heaters can be integrated for complete environmental control.\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 Train Support: 210mm Back Focus and a 3\" Crayford Focuser\u003c\/h3\u003e\n\u003cp\u003eThe ODK14Tr is designed to accommodate complex and heavy imaging trains. It provides a generous 210mm of back focus, measured from the rear of the mirror cell. This extensive travel leaves ample room for accessories like off-axis guiders, large filter wheels, rotators, and large-format cameras without concern for reaching focus.\u003c\/p\u003e\n\u003cp\u003eFocusing is handled by a robust 3\" Crayford focuser with a 10:1 reduction ratio. The large diameter prevents vignetting on full-frame and larger sensors, while the fine-focus knob allows for the precise adjustments necessary to achieve critical focus at the 2380mm focal length. The entire assembly attaches to your mount via a sturdy, CNC-machined aluminum dovetail plate with integrated supports for maximum stability.\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\u003eODK14Tr vs. CDK Designs: Understanding Astrograph Trade-Offs\u003c\/h3\u003e\n\u003cp\u003eWhen choosing a high-end astrograph, the Orion Optics UK Optimized Dall-Kirkham (ODK) is often compared to Corrected Dall-Kirkham (CDK) designs. Both aim for a large, flat, coma-free field, but they achieve it through different optical philosophies.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eODK Approach:\u003c\/strong\u003e The ODK uses an ellipsoidal primary and a spherical secondary. A spherical surface is the simplest to manufacture to an extremely high degree of smoothness, minimizing scatter. The significant off-axis coma inherent in this design is then eliminated with a dedicated 3-lens corrector placed before the focal plane.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCDK Approach:\u003c\/strong\u003e A CDK typically uses an ellipsoidal primary and an aspheric (hyperbolic) secondary, along with a corrector. The aspheric secondary corrects for coma natively, reducing the workload of the corrector lenses. The trade-off is the increased complexity and cost of figuring the aspheric secondary surface.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThe ODK14Tr's design represents a pragmatic choice, prioritizing the manufacturability of its core components to achieve exceptional surface quality while using a powerful, modern corrector to deliver a final image that is sharp and flat across its \u0026gt;52mm field.\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 kind of mount is required for the ODK14Tr OTA?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith an approximate weight of \u003cstrong\u003e26kg\u003c\/strong\u003e for the optical tube alone, plus the added weight of a large camera, filter wheel, and guider, a heavy-duty, observatory-class mount is required. Look for a German equatorial mount with a stated instrument capacity of at least 50kg (110 lbs) to ensure stable, accurate tracking for long-exposure astrophotography.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the ODK14Tr perform on a large target like the Andromeda Galaxy (M31) with a full-frame sensor?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ODK14Tr is an excellent instrument for such a target. Its \u003cstrong\u003e\u0026gt;52mm corrected image circle\u003c\/strong\u003e fully illuminates a standard full-frame sensor (43mm diagonal) with no vignetting. The \u003cstrong\u003e2380mm focal length\u003c\/strong\u003e provides enough image scale to resolve individual dust lanes, star-forming regions, and globular clusters within M31, while still being wide enough to capture a significant portion of the galaxy's sprawling disk.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does the 210mm back focus of the ODK14Tr allow me to do?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e210mm of back focus\u003c\/strong\u003e provides exceptional flexibility for building a comprehensive imaging train. It allows you to easily incorporate multiple accessories between the focuser and the camera sensor, such as:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eAn off-axis guider (OAG)\u003c\/li\u003e\n\u003cli\u003eA large-format filter wheel (e.g., 5- or 7-position 50mm square)\u003c\/li\u003e\n\u003cli\u003eAn electronic field rotator\u003c\/li\u003e\n\u003cli\u003eAn adaptive optics unit\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThis generous spacing is a key feature for advanced imagers who need to accommodate a full suite of equipment without compromising the ability to reach focus.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do the 3 cooling fans on the ODK14Tr improve imaging?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e3 controllable fans\u003c\/strong\u003e are crucial for thermal management. They actively pull air across the back of the 350mm primary mirror, forcing it to cool down to the ambient nighttime temperature much faster than it would passively. This minimizes \"mirror seeing,\" the image-degrading turbulence created by warm air rising from a mirror that is still warmer than its surroundings. The result is sharper images, sooner in your observing session.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the ODK14Tr's f\/6.8 focal ratio suitable for imaging faint nebulae like the Elephant's Trunk Nebula (IC 1396)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, \u003cstrong\u003ef\/6.8\u003c\/strong\u003e is a very capable focal ratio for faint nebulae, especially when paired with a large \u003cstrong\u003e350mm aperture\u003c\/strong\u003e. While not as fast as dedicated hyper-widefield systems, it offers a superb balance, collecting a great deal of light while providing the high resolution needed to capture intricate details in structures like the pillars and Bok globules within IC 1396. Modern, low-noise CMOS sensors make this focal ratio highly efficient for both broadband and narrowband imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat do the spot sizes of 2.1μm and 5.6μm mean for my images with the ODK14Tr?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThese figures quantify the sharpness of the telescope. A \u003cstrong\u003e2.1μm spot size on-axis\u003c\/strong\u003e and \u003cstrong\u003e5.6μm at the field edge\u003c\/strong\u003e means that the telescope focuses starlight into incredibly tight, concentrated points. Most modern astronomy cameras have pixel sizes between 2.5μm and 9μm. Because the ODK14Tr's spot sizes are smaller than or comparable to these pixel sizes, it ensures that the telescope's optics will not be the limiting factor in your image resolution; you will get the full benefit of your camera's sensor, with sharp, pinpoint stars across the entire frame.\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\u003eOptimized Dall-Kirkham (ODK)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Mirror Diameter\u003c\/td\u003e\n\u003ctd\u003e350mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Length\u003c\/td\u003e\n\u003ctd\u003e2380mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/6.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrector\u003c\/td\u003e\n\u003ctd\u003eMulti-coated 3-lens design\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFlat Field Size\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;52mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpot Size (On-Axis)\u003c\/td\u003e\n\u003ctd\u003e2.1μm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpot Size (Field Edge)\u003c\/td\u003e\n\u003ctd\u003e5.6μm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Mirror Size\u003c\/td\u003e\n\u003ctd\u003e136mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focus\u003c\/td\u003e\n\u003ctd\u003e210mm (from rear of mirror cell, ±1mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e3\" Crayford with 10:1 reduction\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\u003e700mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Diameter\u003c\/td\u003e\n\u003ctd\u003e400mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube Weight\u003c\/td\u003e\n\u003ctd\u003eapprox. 26kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMirror Cell\u003c\/td\u003e\n\u003ctd\u003eHoneycomb CNC machined aluminium\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCooling System\u003c\/td\u003e\n\u003ctd\u003e3 controllable fans (heaters optional)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAttachment Method\u003c\/td\u003e\n\u003ctd\u003eCNC machined aluminium dovetail with supports\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\"\u003eODK14Tr Truss 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\u003c\/ul\u003e\n\u003c\/li\u003e\n\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":52942366572829,"sku":"OOUK-ODK14TR-OPTICAL-TUBE-ASSEMBLY","price":20225.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Logo_a024eb5b-9702-4d62-82e4-d3c70289f9df.jpg?v=1789606940"},{"product_id":"orion-optics-uk-odk16tr-optical-tube-assembly","title":"Orion Optics UK ODK16Tr Truss Optical Tube Assembly","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e400mm (16\") Optimized Dall-Kirkham Optics\u003c\/li\u003e\n\u003cli\u003e2720mm Focal Length (f\/6.8)\u003c\/li\u003e\n\u003cli\u003e\u0026gt;52mm Fully Corrected and Illuminated Image Circle\u003c\/li\u003e\n\u003cli\u003e2.4µm On-Axis Spot Size\u003c\/li\u003e\n\u003cli\u003eCarbon Fibre Sandwich Truss Tube Construction\u003c\/li\u003e\n\u003cli\u003e3\" Crayford Focuser with 10:1 Reduction\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 ODK16Tr Truss Optical Tube Assembly\u003c\/h2\u003e\n\u003cp\u003eThe Orion Optics UK ODK16Tr is an observatory-class astrograph, combining a 400mm primary mirror with a fast f\/6.8 focal ratio to deliver professional imaging results. Its 3-lens corrector illuminates a flat field greater than 52mm in diameter, producing pinpoint stars with a 2.4µm spot size on-axis and 6.0µm at the field edge. The entire optical system is housed in a thermally stable carbon fibre sandwich truss tube weighing approximately 36kg and supported by a robust 3\" Crayford focuser.\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\u003eODK16Tr: A 400mm f\/6.8 Corrected Dall-Kirkham Astrograph\u003c\/h3\u003e\n\u003cp\u003eThe ODK16Tr's optical design starts with a 400mm primary mirror in an optimized Dall-Kirkham configuration, which uses an elliptical primary and a spherical secondary. This combination is precisely figured in-house by Orion Optics UK's master opticians. To eliminate the off-axis coma inherent in the standard DK design, a dedicated multi-coated 3-lens corrector is permanently installed, creating a coma-free, flat-field instrument with a 2720mm focal length.\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 \u0026gt;52mm Flat Field with 2.4µm On-Axis Spots\u003c\/h3\u003e\n\u003cp\u003eThis instrument is engineered for large-format sensors. The optical system produces a fully illuminated and corrected image circle greater than 52mm, comfortably covering full-frame (43mm diagonal) and many medium-format astrophotography cameras. The correction is exceptional, delivering an incredibly tight 2.4µm spot size on-axis and maintaining 6.0µm spots at the extreme edge of the field, ensuring that every pixel on your large sensor captures a sharp, aberration-free star.\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 Truss and 3-Fan Cooling\u003c\/h3\u003e\n\u003cp\u003eMechanical and thermal stability are critical at this scale. The ODK16Tr uses a carbon fibre sandwich material for its truss tube, which offers superior stiffness and a near-zero coefficient of thermal expansion to hold focus through temperature changes. The open truss design, weighing approximately 36kg, allows the 400mm primary mirror to acclimate rapidly, a process accelerated by three controllable cooling fans integrated into the CNC-machined honeycomb mirror cell. For maximum contrast, an optional light shroud is recommended to block stray light.\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\u003e3\" Crayford Focuser and 216mm of Back Focus\u003c\/h3\u003e\n\u003cp\u003eThe imaging train is anchored by a heavy-duty 3\" Crayford focuser with a 10:1 fine-adjustment knob, capable of supporting large cameras, filter wheels, and off-axis guiders without flexure. The system provides a generous 216mm of back focal distance measured from the rear of the mirror cell. This ample spacing gives you complete flexibility to configure your ideal imaging setup with rotators, adaptive optics, and other accessories while still reaching perfect focus.\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\u003eODK16Tr vs. Ritchey-Chrétien: Field Correction and Spot Size\u003c\/h3\u003e\n\u003cp\u003eWhile the Ritchey-Chrétien (RC) is a common choice for two-mirror astrographs, the corrected Dall-Kirkham offers distinct advantages. An RC naturally corrects for coma but leaves off-axis astigmatism, which can elongate stars at the edge of the field. The ODK16Tr's integrated 3-lens corrector is specifically designed to eliminate both coma and astigmatism, resulting in rounder stars and smaller spot sizes across its entire \u0026gt;52mm field of view. This design delivers a higher level of performance for imagers using the largest available sensors.\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 size camera sensor can the ODK16Tr fully illuminate?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ODK16Tr is designed to fully illuminate and correct an image circle \u003cstrong\u003egreater than 52mm\u003c\/strong\u003e in diameter. This comfortably covers professional full-frame sensors (e.g., Sony IMX455, 43mm diagonal) and even larger medium-format sensors like the KAF-16803 (39mm diagonal) with no vignetting from the optical system.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat class of mount is required for the ODK16Tr OTA?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWith a tube weight of approximately \u003cstrong\u003e36kg (around 80 lbs)\u003c\/strong\u003e before adding a camera and accessories, the ODK16Tr requires a high-capacity, observatory-grade equatorial mount. Look for mounts with a specified instrument capacity of at least 100-120 lbs (45-55 kg) to ensure stability for long-exposure imaging.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the ODK16Tr's design help maintain focus during temperature drops?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe ODK16Tr uses a \u003cstrong\u003ecarbon fibre sandwich\u003c\/strong\u003e material for its truss tube. Carbon fibre has an extremely low coefficient of thermal expansion, meaning it does not shrink or expand significantly as temperatures change overnight. This keeps the distance between the primary and secondary mirrors constant, preventing focus shift and ensuring sharp images throughout your session.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the ODK16Tr's f\/6.8 focal ratio suitable for imaging faint nebulae like the Veil Nebula (NGC 6960)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, absolutely. While f\/6.8 is not as \"fast\" as some dedicated wide-field refractors, the ODK16Tr's massive \u003cstrong\u003e400mm aperture\u003c\/strong\u003e gathers a tremendous amount of light. This light-gathering power makes it highly effective for narrowband imaging of faint emission nebulae, resolving fine filamentary details in targets like the Veil Nebula or the Cygnus Loop with impressive signal-to-noise ratios.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow will the ODK16Tr's 2720mm focal length frame a target like the Andromeda Galaxy (M31)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe \u003cstrong\u003e2720mm focal length\u003c\/strong\u003e provides a high-magnification view ideal for detailed studies of smaller deep-sky objects or for creating mosaics of large ones. A full-frame camera on the ODK16Tr would frame the bright core of the Andromeda Galaxy (M31) in incredible detail, resolving individual dust lanes and star-forming regions, but it would not capture the entire 3-degree span of the galaxy in a single shot.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDo I need to add a light shroud to the ODK16Tr's truss tube?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, a light shroud is highly recommended. The open truss design promotes rapid cooling but is susceptible to stray light from external sources and can be more prone to dew formation on the secondary mirror. A fabric light shroud will significantly improve image contrast by creating a dark interior and will also help protect the optics from dew.\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\u003ePrimary Mirror Diameter\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\u003e2720mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal Ratio\u003c\/td\u003e\n\u003ctd\u003ef\/6.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCorrector Design\u003c\/td\u003e\n\u003ctd\u003eMulti-coated 3 lens\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFlat Field Size\u003c\/td\u003e\n\u003ctd\u003e\u0026gt;52mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpot Size on Axis\u003c\/td\u003e\n\u003ctd\u003e2.4μm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSpot Size at Field Edge\u003c\/td\u003e\n\u003ctd\u003e6.0μm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSecondary Mirror Size\u003c\/td\u003e\n\u003ctd\u003e152mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBack Focal Distance\u003c\/td\u003e\n\u003ctd\u003e216mm (from rear of mirror cell, ±1mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocuser\u003c\/td\u003e\n\u003ctd\u003e3\" Crayford with 10:1 reduction\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\u003e820mm\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. 36kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMirror Cell\u003c\/td\u003e\n\u003ctd\u003eHoneycomb CNC machined aluminium\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMirror \u0026amp; Tube Cooling\u003c\/td\u003e\n\u003ctd\u003e3 controllable fans, heaters optional\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAttachment Method\u003c\/td\u003e\n\u003ctd\u003eCNC machined aluminium dovetail with supports\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\"\u003eODK16Tr Truss 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\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":52942368145693,"sku":"OOUK-ODK16TR-OPTICAL-TUBE-ASSEMBLY","price":27897.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Logo_689b3e0d-88fa-4a57-8d85-797329a5a5a8.jpg?v=1789606948"},{"product_id":"orion-optics-uk-odk18tr-optical-tube-assembly","title":"Orion Optics UK ODK18Tr Truss Optical Tube Assembly","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eOptimized Dall-Kirkham (ODK) Optical Design\u003c\/li\u003e\n\u003cli\u003eOpen Truss Tube Framework\u003c\/li\u003e\n\u003cli\u003ePrimary and Secondary Mirrors by Orion Optics UK\u003c\/li\u003e\n\u003cli\u003eEngineered for Astrophotography\u003c\/li\u003e\n\u003cli\u003eAvailable with Multiple Optical Precision Grades\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\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 ODK18Tr Truss Optical Tube Assembly\u003c\/h2\u003e\n      \u003cp\u003eThe Orion Optics UK ODK18Tr is an imaging-first instrument built around the advanced Optimized Dall-Kirkham optical design. Its open truss structure is engineered for rapid thermal equalization and mechanical rigidity, providing a stable platform for demanding astrophotography. This OTA combines a corrected, coma-free field with the meticulous, hand-finished optical quality Orion Optics UK is known for, delivering professional-grade results from a permanent observatory or a portable deep-sky setup.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"DAV-bg-light\"\u003e\n    \u003cdiv class=\"DAV-section\"\u003e\n      \u003ch3\u003eThe Optimized Dall-Kirkham Advantage\u003c\/h3\u003e\n      \u003cp\u003eThe ODK18Tr employs an Optimized Dall-Kirkham (ODK) design, a significant advancement over the classical Dall-Kirkham. While the base design uses an elliptical primary and spherical secondary, the ODK incorporates a corrector lens group to eliminate off-axis coma and deliver a flat, sharp field of view. This makes the ODK18Tr exceptionally well-suited for use with modern large-format CMOS and CCD sensors, ensuring point-like stars across the entire frame without the need for an additional external coma corrector.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n  \n  \u003cdiv class=\"DAV-bg-light\"\u003e\n    \u003cdiv class=\"DAV-section\"\u003e\n      \u003ch3\u003eOpen Truss Framework for Thermal Stability\u003c\/h3\u003e\n      \u003cp\u003eUnlike a solid-tube design, the ODK18Tr's open truss framework allows ambient air to circulate freely around the primary mirror. This design minimizes the risk of tube currents and allows the optics to reach thermal equilibrium with the night air much faster. The result is a more stable image, free from the distortions caused by trapped warm air, enabling you to start high-resolution imaging sooner and maintain focus throughout the night.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"DAV-bg-light\"\u003e\n    \u003cdiv class=\"DAV-section\"\u003e\n      \u003ch3\u003eOrion Optics UK Hand-Figured Optics: A Choice of Precision Grades\u003c\/h3\u003e\n      \u003cp\u003eAt the heart of every ODK18Tr are primary and secondary mirrors manufactured and hand-figured in the Orion Optics UK workshop. Rather than relying solely on machine polishing, skilled opticians refine each optical surface to an exceptional standard of accuracy. This process allows Orion Optics UK to offer several grades of optical precision, measured in Peak-to-Valley (PV) wavefront error, allowing you to select the level of optical perfection your imaging demands.\u003c\/p\u003e\n      \u003cul\u003e\n        \u003cli\u003e\n\u003cstrong\u003eStandard Optics (1\/4 PV):\u003c\/strong\u003e The minimum grade, offering excellent performance for general deep-sky imaging.\u003c\/li\u003e\n        \u003cli\u003e\n\u003cstrong\u003eProfessional Optics (1\/6 PV):\u003c\/strong\u003e A significant step up, providing higher contrast and sharper detail, ideal for more serious imagers.\u003c\/li\u003e\n        \u003cli\u003e\n\u003cstrong\u003eResearch Grade (1\/8 PV):\u003c\/strong\u003e A premium level of correction that reveals finer planetary detail and resolves tighter star clusters.\u003c\/li\u003e\n        \u003cli\u003e\n\u003cstrong\u003eUltra Grade (1\/10 PV):\u003c\/strong\u003e The highest level of precision offered, for those who require the most accurate and high-contrast images possible from the aperture.\u003c\/li\u003e\n      \u003c\/ul\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n\u003c\/div\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is an Optimized Dall-Kirkham (ODK) and how does the ODK18Tr benefit from it?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eAn \u003cstrong\u003eOptimized Dall-Kirkham (ODK)\u003c\/strong\u003e is a type of Cassegrain telescope that uses an elliptical primary mirror, a spherical secondary mirror, and a small corrector lens group near the focuser. This design corrects for off-axis coma and field curvature, producing a wide, flat, and sharp field of view that is ideal for astrophotography with large sensor cameras.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat are the advantages of the ODK18Tr's truss tube design?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThe ODK18Tr's open truss design offers two primary benefits. First, it promotes \u003cstrong\u003erapid thermal acclimation\u003c\/strong\u003e by allowing air to flow freely over the optics, reducing cooldown time and minimizing image-degrading tube currents. Second, a well-designed truss structure provides exceptional \u003cstrong\u003estiffness and rigidity\u003c\/strong\u003e, which helps maintain precise optical alignment regardless of the telescope's orientation.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I choose the right Orion Optics UK optical grade for the ODK18Tr?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThe choice depends on your primary observing goals and budget.\n      \u003c\/p\u003e\n\u003cul\u003e\n        \u003cli\u003eFor general deep-sky imaging, the \u003cstrong\u003e1\/4 PV Standard\u003c\/strong\u003e optics will deliver excellent results.\u003c\/li\u003e\n        \u003cli\u003eFor those seeking higher contrast and resolving finer details, the \u003cstrong\u003e1\/6 PV Professional\u003c\/strong\u003e grade is a worthwhile upgrade.\u003c\/li\u003e\n        \u003cli\u003eFor planetary imaging or scientific work where maximum resolution is critical, the \u003cstrong\u003e1\/8 PV Research\u003c\/strong\u003e or \u003cstrong\u003e1\/10 PV Ultra\u003c\/strong\u003e grades ensure the highest possible optical performance.\u003c\/li\u003e\n      \u003c\/ul\u003e\n    \n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eIs the ODK18Tr OTA suitable for visual astronomy?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eWhile the ODK18Tr is optically optimized for imaging, its high-contrast, coma-free views are also superb for visual observation. The large aperture will provide stunning views of deep-sky objects like the Orion Nebula (M42) and distant galaxies, while the high-quality optics will reveal intricate detail on Jupiter and Saturn. Its primary design focus, however, remains astrophotography.\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 ODK18Tr OTA?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eAn 18-inch truss tube OTA is a large and heavy instrument. It requires a substantial, observatory-class German equatorial mount with a high payload capacity. You should consider mounts from manufacturers like Software Bisque, Astro-Physics, or 10Micron capable of handling the telescope's weight and moment arm to ensure stable, accurate tracking for long-exposure astrophotography.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the open truss design of the ODK18Tr require a light shroud?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eYes, for best results, a light shroud is highly recommended. The open truss tube can allow stray light from external sources (like house lights or the moon) to enter the optical path, which can reduce contrast in your images. A fabric light shroud blocks this stray light while still allowing for air circulation, preserving both image contrast and thermal stability.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n  \u003ctable class=\"DAV-specifications\"\u003e\n    \u003ctbody\u003e\n      \n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n  \u003cul class=\"DAV-grid\"\u003e\n    \n  \u003c\/ul\u003e\n\u003c\/li\u003e\n\n\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":52942368637213,"sku":"OOUK-ODK18TR-OPTICAL-TUBE-ASSEMBLY","price":43433.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Logo_4ecd5251-bae0-4ed8-a630-f69508cd963f.jpg?v=1789606956"},{"product_id":"orion-optics-uk-odk20tr-optical-tube-assembly","title":"Orion Optics UK ODK20Tr Optical tube assembly","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003e500mm truss-tube Dall-Kirkham\u003c\/li\u003e\n\u003cli\u003ef\/6.8 carbon-fibre-sandwich optics\u003c\/li\u003e\n\u003cli\u003eOpen truss for shorter packed length\u003c\/li\u003e\n\u003cli\u003eBuilt to order in the UK\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\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\u003eODK20Tr Truss Telescope\u003c\/h2\u003e\n\u003cp\u003eThe ODK20Tr is a 500mm truss-tube Dall-Kirkham telescope in Orion Optics UK's ODKTr range -- the same f\/6.8 carbon-fibre-sandwich optical design as the standard ODK range, in an open truss configuration for a shorter packed tube length.\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\u003eTruss Design for Transport\u003c\/h3\u003e\n\u003cp\u003eThe open truss structure packs down to a shorter length than the standard ODK tube while keeping the same f\/6.8 optical design. Individually built to order in the UK; contact Orion Optics UK for full ODK20Tr specification.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\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\u003e500mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFocal ratio\u003c\/td\u003e\n\u003ctd\u003ef\/6.8\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTube design\u003c\/td\u003e\n\u003ctd\u003eOpen truss\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\"\u003eODK20Tr 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\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":52942368702749,"sku":"OOUK-ODK20TR-OPTICAL-TUBE-ASSEMBLY","price":53215.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Logo_29a85537-4e31-4600-96a7-4a87bdef9420.jpg?v=1789606965"},{"product_id":"orion-optics-uk-odk24tr-optical-tube-assembly","title":"Orion Optics UK ODK24Tr Truss Optical Tube Assembly","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eOptimized Dall-Kirkham (ODK) Optical Design\u003c\/li\u003e\n\u003cli\u003eCorrected, Coma-Free Flat Field for Imaging\u003c\/li\u003e\n\u003cli\u003eOpen Truss Tube for Thermal Stability and Rigidity\u003c\/li\u003e\n\u003cli\u003eHand-Finished Primary and Secondary Mirrors\u003c\/li\u003e\n\u003cli\u003eManufactured by Orion Optics UK\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 ODK24Tr Truss Optical Tube Assembly\u003c\/h2\u003e\n      \u003cp\u003eThe Orion Optics UK ODK24Tr Truss Optical Tube Assembly represents a pinnacle of astrographic design, combining a large-aperture, flat-field Optimized Dall-Kirkham (ODK) optical system with a rigid, thermally stable open truss framework. Engineered for serious imagers, the ODK24Tr leverages Orion Optics UK's renowned expertise in hand-figuring large optics to deliver professional-grade astronomical performance.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"DAV-bg-light\"\u003e\n    \u003cdiv class=\"DAV-section\"\u003e\n      \u003ch3\u003eOptimized Dall-Kirkham: A Coma-Free, Flat-Field Astrograph\u003c\/h3\u003e\n      \u003cp\u003eThe ODK optical system is an advanced version of the Dall-Kirkham design, featuring an elliptical primary mirror, a spherical secondary, and a built-in corrector lens group. This configuration produces a wide, flat, and fully illuminated field of view that is free from off-axis coma, making the ODK24Tr ideal for use with modern large-format CMOS and CCD cameras.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n    \u003cdiv class=\"DAV-bg-light\"\u003e\n    \u003cdiv class=\"DAV-section\"\u003e\n      \u003ch3\u003eOpen Truss Framework: Thermal Stability and Rigidity\u003c\/h3\u003e\n      \u003cp\u003eThe open truss structure of the ODK24Tr provides exceptional mechanical rigidity while minimizing weight compared to a solid tube. This design allows the primary mirror to acclimate rapidly to ambient nighttime temperatures, reducing tube currents and ensuring the sharpest possible images. While the open frame excels at thermal management, using a light shroud is recommended to block stray light and protect the optics from dew.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"DAV-bg-light\"\u003e\n    \u003cdiv class=\"DAV-section\"\u003e\n      \u003ch3\u003eOrion Optics UK Hand-Figured Optics: The Path to Wavefront Accuracy\u003c\/h3\u003e\n      \u003cp\u003eAt the heart of the ODK24Tr are optics hand-finished by Orion Optics UK's master opticians. Every mirror is subjected to rigorous testing with a Zygo laser interferometer to ensure its surface accuracy meets exacting standards. This commitment to precision is what separates OOUK from mass-produced instruments.\u003c\/p\u003e\n      \u003cp\u003eOrion Optics UK offers multiple grades of optical accuracy, from their excellent 1\/4 PV wavefront Standard optics to their near-perfect 1\/10 PV wavefront Ultra grade. This dedication to quantifiable optical quality ensures that the telescope's performance is limited only by the seeing conditions, not by the mirror itself.\u003c\/p\u003e\n    \u003c\/div\u003e\n  \u003c\/div\u003e\n\n\u003c\/div\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n  \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is an \"Optimized Dall-Kirkham\" (ODK) design on the ODK24Tr?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThe \u003cstrong\u003eOptimized Dall-Kirkham (ODK)\u003c\/strong\u003e is a specialized Cassegrain-style telescope designed for astrophotography. It uses an elliptical primary mirror, a spherical secondary, and a corrector lens system. This combination corrects for optical aberrations like coma and provides a flat focal plane, resulting in sharp, pinpoint stars across a wide, well-illuminated field of view, which is critical for imaging with large sensors.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat are the advantages of the ODK24Tr's truss tube design?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThe truss design offers two main benefits for a large telescope like the ODK24Tr:\u003c\/p\u003e\n    \u003cul\u003e\n    \u003cli\u003e\n\u003cstrong\u003eThermal Stability:\u003c\/strong\u003e The open frame allows air to circulate freely around the primary mirror, letting it cool down to the ambient temperature much faster than a solid tube. This minimizes internal air currents (tube seeing) that can degrade image sharpness.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eHigh Rigidity-to-Weight Ratio:\u003c\/strong\u003e The truss structure provides a very stiff platform to maintain optical alignment without the immense weight of a comparable solid tube, making it more manageable on a high-capacity mount.\u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does Orion Optics UK's mirror quality mean for the ODK24Tr?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eOrion Optics UK (OOUK) is renowned for its hand-figured and finished mirrors, which are tested on a Zygo interferometer to guarantee a specific level of wavefront accuracy (e.g., 1\/4 PV, 1\/6 PV, or higher). For the ODK24Tr, this means the optics are crafted to an extremely high standard of precision, delivering maximum contrast and sharpness for demanding planetary and deep-sky imaging.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eHow would the ODK24Tr perform for imaging a large target like the Andromeda Galaxy (M31)?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eThe ODK24Tr is exceptionally well-suited for large targets like the Andromeda Galaxy (M31). Its flat-field, coma-corrected optics are designed to illuminate large camera sensors evenly, ensuring that stars are sharp from the galaxy's core to its outermost spiral arms. The large aperture gathers immense amounts of light, revealing faint dust lanes and star-forming regions with shorter exposure times.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eIs the ODK24Tr suitable for planetary viewing, for example, observing the Cassini Division on Saturn?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eAbsolutely. While designed as an astrograph, the high-precision optics of the ODK24Tr make it a superb planetary instrument. The certified wavefront accuracy from Orion Optics UK ensures maximum image contrast, which is essential for resolving fine details like the Cassini Division in Saturn's rings, cloud bands on Jupiter, or surface features on Mars.\u003c\/p\u003e\n  \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n    \u003ch3 class=\"DAV-accordion-Q\"\u003eWhy is thermal management important for a large telescope like the ODK24Tr?\u003c\/h3\u003e\n  \u003c\/div\u003e\n  \u003cdiv class=\"DAV-accordion-A\"\u003e\n    \u003cp\u003eFor any large-aperture telescope, thermal management is critical. If the primary mirror is warmer than the surrounding air, it creates a boundary layer of turbulent air directly in the light path, which blurs the image—a phenomenon known as \"mirror seeing.\" The ODK24Tr's open truss design helps prevent this by allowing the mirror to reach thermal equilibrium with the environment quickly, preserving the telescope's high-resolution capabilities.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n  \u003ctable class=\"DAV-specifications\"\u003e\n    \u003ctbody\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/li\u003e\n\n\u003cli\u003e\n  \u003cul class=\"DAV-grid\"\u003e\n  \u003c\/ul\u003e\n\u003c\/li\u003e\n\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":52942368932125,"sku":"OOUK-ODK24TR-OPTICAL-TUBE-ASSEMBLY","price":118331.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Orion-Optics-UK-Logo_f71c6b05-8e6e-4145-9358-b4b28aa1f910.jpg?v=1789606973"}],"url":"https:\/\/davidastro.com\/fr-us\/collections\/ritchey-chretien-and-dall-kirkham.oembed","provider":"David Astro","version":"1.0","type":"link"}