{"product_id":"used-astro-tech-2-99-reflectivity-dielectric-mirror-diagonal-for-sct","title":"Used Astro-Tech 2\" 99% Reflectivity Dielectric Mirror Diagonal For SCT","description":"\u003cp\u003e\u003cmeta charset=\"utf-8\"\u003eThis is an Astro-Tech 2\" Dielectric Diagonal.  It is in perfect, pristine condition:  the mirror is clean, and the body is, of course, completely unmarked.  \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e90-degree diagonal features sophisticated, lab-tested dielectric coatings that boast an astounding 99 percent reflectivity\u003c\/li\u003e\n\u003cli\u003eDielectric mirror coatings are more durable and more reflective than enhanced aluminum coatings\u003c\/li\u003e\n\u003cli\u003eDiagonal provides a comfortable 90-degree viewing orientation when observing the night sky through a refractor\u003c\/li\u003e\n\u003cli\u003eMachined and anodized aluminum housing features machine-threaded baffles for optimized contrast\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThis 2” dielectric mirror-type star diagonal is an outstanding value. At this low price, if there ever was a bargain in astronomy, this is it.\u003c\/p\u003e\n\u003cp\u003eThis 2” Astro-Tech first-surface mirror star diagonal has state-of-the-art 46-layer dielectric mirror coatings for a full 99% reflectivity, higher than the 88% of a conventional aluminum diagonal or the 96-97% of an easily-tarnished silver diagonal.\u003c\/p\u003e\n\u003cp\u003eThe durable ion-deposited dielectric coatings on the mirror’s finely-polished 10mm thick 1\/10th wave BK7 optical glass substrate also provide higher contrast and resolution during critical planetary, lunar, and binary star observations.\u003c\/p\u003e\n\u003cp\u003eThe supplied 1.25” eyepiece adapter uses a compression ring to hold eyepieces in place. The scope-side barrel of the 1.25” adapter has a subtle slanted groove to keep it from accidentally slipping out of the 2” diagonal. Dust covers are provided for the 1.25” adapter and the diagonal’s 2” barrel.\u003c\/p\u003e\n\u003cp\u003eThe interior of the diagonal body and the inside of the focuser-side barrel are treated with light absorbing materials. The focuser-side barrel is also internally anti-reflection threaded for even higher contrast. The barrel is threaded to accept standard 2” filters.\u003c\/p\u003e\n\u003cp\u003eA subtle slanted groove cut into the outside of the focuser-side 2” barrel engages with your telescope’s focuser thumbscrew to act as a safety stop. This keeps the diagonal from falling should the scope’s thumbscrew loosen slightly from cold or use.\u003c\/p\u003e\n\u003cp\u003eThis diagonal is a visible improvement over the conventional 2\" diagonal provided with many telescopes capable of using 2” optics. It can be used with a Schmidt-Cassegrain or Maksutov-Cassegrain telescope with a suitable adapter, included. It is an absolutely premium 2” 99% reflectivity dielectric self-centering star diagonal at a fraction the price of competitive models with equivalent performance and build quality. The same performance, for as little as half the price. If there ever was a bargain in astronomy, this is it.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ctable id=\"product-attribute-specs-table\" class=\"table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd class=\"data\"\u003e17 oz.\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Astro-Tech","offers":[{"title":"Default Title","offer_id":49588329349379,"sku":"U2609-TC-AT2D","price":80.0,"currency_code":"USD","in_stock":false}],"url":"https:\/\/milehighastro.com\/products\/used-astro-tech-2-99-reflectivity-dielectric-mirror-diagonal-for-sct","provider":"Mile High Astronomy","version":"1.0","type":"link"}