{"product_id":"used-altair-2-inch-positive-lock-90-degree-prism-diagonal-push-fit-for-refractors","title":"USED - Altair 2 inch Positive Lock 90 Degree Prism Diagonal Push-fit for Refractors","description":"\u003ch2\u003eUSED GEAR INFORMATION\u003c\/h2\u003e\n\u003cp\u003eThis diagonal is in excellent condition. The prism surfaces appear in pristine condition. There are no signs of cosmetic imperfections.\u003c\/p\u003e\n\u003ch2\u003eDetails\u003c\/h2\u003e\n\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003e\u003cspan\u003ePrism diagonals give less scatter and therefore better contrast than diagonals using reflective mirror surfaces, including dielectric ones.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003ePrism diagonals are therefore especially good for high power planetary and lunar observing where sharpness and contrast are critical, especially with high quality refractors with an F7 or longer focal ratio.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003eRegardless of the coating method used, all reflecting mirrors consist of tiny particles evaporated onto glass which, no matter how carefully reposited, will produce scatter and reduce contrast.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003eThe Altair prism diagonal has a BK7\/K9 prism with excellent clarity and smoothness, as well as special anti reflective coatings.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003eThe prism surface cannot even be seen with the naked eye when looking into the diagonal, unless there is dust on the surface.\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eThe special \"Positive Lock\" compression ring will never mar your accessories and is completely secure.\u003c\/li\u003e\n\u003cli\u003eIdeal for refractors and large eyepieces or binoviewers.\u003c\/li\u003e\n\u003cli\u003eTop quality prism with special broadband multi-coatings.\u003c\/li\u003e\n\u003cli\u003eClear aperture of 43mm, with an optical path distance of 125mm.\u003c\/li\u003e\n\u003cli\u003eEssentially maintenance free.\u003c\/li\u003e\n\u003cli\u003eIncludes a 2\" to 1.25\" adapter with brass compression ring for smaller 1.25\" eyepieces or GPCAM\/Hypercam.\u003c\/li\u003e\n\u003cli\u003eThreaded for use with standard 2\" astro filters (M48x0.75mm thread).\u003c\/li\u003e\n\u003cli\u003eBlackened interior for high contrast (especially recommended for the moon, sun and planets!).\u003c\/li\u003e\n\u003cli\u003eIncludes dust caps both ends.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Altair","offers":[{"title":"Default Title","offer_id":48456939045113,"sku":"USED-ALTAIR2","price":125.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0869\/6486\/files\/20260529_102927.jpg?v=1780076010","url":"https:\/\/cloudbreakoptics.com\/products\/used-altair-2-inch-positive-lock-90-degree-prism-diagonal-push-fit-for-refractors","provider":"Cloud Break Optics","version":"1.0","type":"link"}