{"title":"Celestron Diagonals","description":"\u003cp\u003eCelestron diagonals turn the light path 90 degrees so you can look into a refractor or SCT from a comfortable position. The basic 1.25\" star diagonal suits entry telescopes, the dielectric star diagonals with twist-lock in 1.25\" and 2\" offer high reflectivity and secure eyepiece clamping, and the 2\" mirror diagonal with XLT coatings accepts wide-field 2\" eyepieces.\u003c\/p\u003e\u003cp\u003eThe 45-degree erect image diagonal gives a correctly oriented view for birding and terrestrial use.\u003c\/p\u003e","products":[{"product_id":"celestron-star-diagonal-1-25","title":"Celestron Star Diagonal - 1.25\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eProvides a comfortable 90° viewing angle\u003c\/li\u003e\n\u003cli\u003eInserts into any 1.25\" telescope focuser or visual back\u003c\/li\u003e\n\u003cli\u003eAccepts standard 1.25\" eyepieces\u003c\/li\u003e\n\u003cli\u003eCorrects image orientation to be right-side-up\u003c\/li\u003e\n\u003cli\u003eIdeal for refractors and catadioptric telescopes\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\u003eCelestron Star Diagonal - 1.25\"\u003c\/h2\u003e\n\u003cp\u003eThe Celestron 1.25\" Star Diagonal redirects your telescope's light path by 90°, allowing for a dramatically more comfortable viewing position. This essential accessory fits any refractor or catadioptric telescope that uses a standard 1.25\" focuser and eyepieces, making it a fundamental upgrade for visual astronomy.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eThe 90° Solution for Comfortable Observing\u003c\/h3\u003e\n\u003cp\u003eViewing objects near the zenith (directly overhead) without a diagonal requires crouching in an awkward, uncomfortable position that causes significant neck strain. By turning the eyepiece out to a 90° angle, this diagonal lets you observe for hours in a relaxed posture, whether you are seated or standing. This simple ergonomic improvement is critical for enjoying long sessions at the eyepiece without fatigue.\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\u003eStandard 1.25\" Fit and Correct-Image Orientation\u003c\/h3\u003e\n\u003cp\u003eDesigned for maximum compatibility, the Celestron 1.25\" diagonal slides directly into the focuser of most refractors, Schmidt-Cassegrain (SCT), and Maksutov-Cassegrain (Mak) telescopes. It also presents an image that is right-side-up, which is more intuitive for navigating the sky than the inverted view seen without a diagonal.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eUniversal Compatibility:\u003c\/strong\u003e The 1.25\" barrel format is the most common standard in astronomy, ensuring this diagonal will work with a vast range of telescopes and eyepieces.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eImage Orientation:\u003c\/strong\u003e The view is corrected vertically, so objects appear upright. The image is, however, reversed from left to right, which is standard for all mirror diagonals and is not a hindrance for astronomical observation.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTerrestrial Viewing Trade-off:\u003c\/strong\u003e Because of the left-right reversal, this diagonal is not recommended for terrestrial viewing where correct image orientation is required. For daytime use, an erecting prism is necessary.\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\"\u003eWhy do I need a star diagonal for my refractor or SCT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA star diagonal, like this Celestron 1.25\" model, is essential for comfortable viewing. Without it, you would have to look straight through the telescope, which becomes extremely difficult and causes neck strain when observing objects high in the sky. The 90° angle allows you to look down into the eyepiece from a comfortable position.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Celestron 1.25\" Star Diagonal work with my Newtonian reflector telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eNo. Newtonian reflectors have their focuser on the side of the tube, which is already at a comfortable 90° angle. Adding a star diagonal would not only be redundant but would also push the eyepiece out too far, preventing the telescope from reaching focus.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does \"right side up, but reversed left-to-right\" mean when viewing the Moon with this diagonal?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eWhen you observe the Moon through the Celestron 1.25\" Star Diagonal, craters and seas will appear upright, just as you see them with your naked eye. However, the left and right sides will be swapped. For example, the Sea of Tranquility (Mare Tranquillitatis), which is on the eastern limb (left side from the northern hemisphere), will appear to be on the right side of the lunar disc.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use this Celestron 1.25\" diagonal for bird watching?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt is not recommended. While the image will be upright, the left-to-right reversal makes it very difficult to follow moving objects like birds or boats. For terrestrial viewing, you should use a 45° or 90° \"correct-image\" or \"erecting\" prism diagonal, which corrects the view on both axes.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes the Celestron 1.25\" Star Diagonal affect the focus of my telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, all diagonals add to the optical path length. Refractor and catadioptric (SCT, Mak) telescopes are designed with enough focus travel to accommodate a diagonal. You will simply need to adjust the focuser to achieve a sharp image. This diagonal will not cause any issues with reaching focus on a compatible telescope.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat telescopes are compatible with the Celestron 1.25\" Diagonal?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis diagonal is compatible with any telescope that uses a 1.25\" focuser and does not have a built-in diagonal. This includes most:\n\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eRefractor telescopes\u003c\/li\u003e\n\u003cli\u003eSchmidt-Cassegrain telescopes (SCTs)\u003c\/li\u003e\n\u003cli\u003eMaksutov-Cassegrain telescopes (Maks)\u003c\/li\u003e\n\u003c\/ul\u003e\n\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\u003eBarrel Size\u003c\/td\u003e\n\u003ctd\u003e1.25\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eViewing Angle\u003c\/td\u003e\n\u003ctd\u003e90°\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eImage Orientation\u003c\/td\u003e\n\u003ctd\u003eRight side up, reversed left-to-right\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatible Telescope Designs\u003c\/td\u003e\n\u003ctd\u003eRefractors, Schmidt-Cassegrain, Maksutov-Cassegrain\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\u003cimg class=\"DAV-img-box\" alt=\"Celestron 1.25 inch Star Diagonal\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/94115-A-1.jpg?v=1686000000\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eCelestron 1.25\" Star Diagonal\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\u003cimg class=\"DAV-img-box\" alt=\"Dust caps for 1.25 inch diagonal\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Celestron-1point25inch-Dustcap.jpg?v=1776900000\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDust Caps\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 2\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/davidastro.com\/pages\/celestron-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eCelestron 2-Year Warranty\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Celestron","offers":[{"title":"Default Title","offer_id":44967146094877,"sku":"CEL-94115-A","price":62.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Celestron-1-25-inch-Star-Diagonal-94115-A-1__33051.1594230250.1280.1280.jpg?v=1684337179"},{"product_id":"celestron-mirror-diagonal-with-xlt-coatings-2","title":"Celestron Mirror Diagonal with XLT Coatings - 2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eInterferometer-tested mirror with 1\/10 wave or better surface accuracy\u003c\/li\u003e\n\u003cli\u003eFeatures Celestron's proprietary XLT optical coatings for maximum light transmission\u003c\/li\u003e\n\u003cli\u003eThreads directly onto the rear cell of Schmidt-Cassegrain telescopes for a secure connection\u003c\/li\u003e\n\u003cli\u003eIncludes a 2\" to 1.25\" adapter for use with any eyepiece format\u003c\/li\u003e\n\u003cli\u003eComes with a protective aluminum storage case\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\u003eCelestron Mirror Diagonal with XLT Coatings - 2\"\u003c\/h2\u003e\n\u003cp\u003eThe Celestron 2\" Mirror Diagonal with XLT Coatings delivers the optical precision required for critical observation, built around a mirror guaranteed to be 1\/10 wave or better. This diagonal securely threads onto the rear cell of a Schmidt-Cassegrain, providing a stable platform for your heaviest 2\" eyepieces while also accommodating 1.25\" eyepieces via the included adapter.\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 1\/10 Wave Mirror with High-Transmission XLT Coatings\u003c\/h3\u003e\n\u003cp\u003eAt the heart of this diagonal is an interferometer-tested mirror with a surface accuracy of 1\/10 wave or better. This level of precision prevents the introduction of optical errors, preserving the sharpness and contrast your telescope is designed to deliver. The mirror surface is treated with Celestron's premier XLT coatings, the same multi-layer coatings used on their high-end telescopes, which dramatically increase light transmission over standard aluminum for visibly brighter images.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eThe 2-Inch Format Advantage for Deep-Sky Observing\u003c\/h3\u003e\n\u003cp\u003eUpgrading to a 2\" diagonal is essential for unlocking wide-field views and observing faint deep-sky objects. The larger barrel allows your telescope's full light cone to illuminate the field stop of a 2\" low-power eyepiece. This results in a significantly wider true field of view and brighter images for large targets like the Andromeda Galaxy (M31) or the Orion Nebula (M42), which cannot be framed in their entirety with a 1.25\" eyepiece at the same 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\u003eSecure SCT Connection and 1.25\" Eyepiece Versatility\u003c\/h3\u003e\n\u003cp\u003eUnlike standard slip-in diagonals that can sag or tilt under the weight of heavy accessories, the Celestron 2\" XLT Diagonal threads directly onto the rear cell of an SCT. This rigid, secure connection ensures perfect optical alignment all night long, even when using large eyepieces or camera adapters. The precision-machined housing holds the mirror in exact collimation, while the included 2\" to 1.25\" adapter lets you switch between eyepiece formats in seconds without compromising 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\u003eCelestron XLT vs. Standard Stock Diagonals: A Worthwhile Upgrade\u003c\/h3\u003e\n\u003cp\u003eMany telescopes come with a basic \"stock\" diagonal, which is typically the weakest link in the optical chain. The Celestron 2\" XLT Diagonal represents a significant upgrade in two key areas.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptical Accuracy:\u003c\/strong\u003e Most standard diagonals use a 1\/4 wave mirror, which can soften fine planetary detail. The 1\/10 wave mirror in the XLT diagonal maintains the sharpness of the primary optics, resulting in higher-resolution views.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLight Throughput:\u003c\/strong\u003e The XLT coatings transmit measurably more light than the simple aluminum coatings on stock diagonals. This difference is immediately apparent on faint objects like galaxies and nebulae, where every photon counts.\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\"\u003eWill the Celestron 2\" XLT Diagonal improve views in my 8\" SCT over the stock diagonal?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, absolutely. An 8\" SCT has excellent optics, and a lower-quality diagonal can limit its potential. The \u003cstrong\u003e1\/10 wave mirror\u003c\/strong\u003e will preserve the fine detail the telescope can resolve, and the \u003cstrong\u003eXLT coatings\u003c\/strong\u003e will provide a noticeably brighter image on deep-sky objects compared to the standard 1.25\" diagonal included with the telescope.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow does the 1\/10 wave mirror help when observing Jupiter or Saturn?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003ePlanetary observation relies on seeing maximum sharpness and contrast. A mirror with 1\/10 wave accuracy introduces virtually no distortion to the light path. This means fine details like Jupiter's cloud bands, the Great Red Spot, or the Cassini Division in Saturn's rings will appear sharper and more defined than with a standard 1\/4 wave diagonal.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the advantage of this mirror diagonal over a prism diagonal?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eFor telescopes with a focal ratio of f\/7 or slower, like an SCT, a high-quality mirror diagonal is generally superior. Mirror diagonals are more color-neutral and do not introduce the chromatic aberration that some prism diagonals can, especially at high magnifications. The XLT mirror coatings also provide excellent light transmission across the entire visual spectrum.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eDoes this Celestron diagonal thread directly onto all SCTs?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThis diagonal is designed to thread onto the standard rear cell of most Schmidt-Cassegrain telescopes, including virtually all models made by Celestron and Meade. It provides a much more secure connection than a slip-in diagonal that relies on a visual back and thumbscrews.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use 2\" filters with the Celestron XLT Diagonal?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The barrel of the diagonal is threaded to accept standard 2\" astronomy filters. You can thread a filter directly onto the diagonal and then insert any 2\" eyepiece, or you can thread filters onto the individual eyepieces themselves.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhy is the included aluminum case for the XLT diagonal important?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eA diagonal's mirror is a sensitive optical surface. The foam-lined aluminum case protects it from dust, moisture, and impacts during transport and storage. Keeping the mirror clean and the housing perfectly aligned is critical to maintaining its 1\/10 wave performance, and the case ensures it stays in pristine condition.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003ctable class=\"DAV-specifications\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eMirror Diagonal\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBarrel Size\u003c\/td\u003e\n\u003ctd\u003e2\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMirror Accuracy\u003c\/td\u003e\n\u003ctd\u003e1\/10 wave or better\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCoatings\u003c\/td\u003e\n\u003ctd\u003eXLT\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAdapter\u003c\/td\u003e\n\u003ctd\u003e2\" to 1.25\" included\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTelescope Connection\u003c\/td\u003e\n\u003ctd\u003eThreads on to SCT rear cell\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\u003cimg class=\"DAV-img-box\" alt=\"Celestron 2-inch Mirror Diagonal with XLT Coatings\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/celestron-2-xlt-sct-diagonal-1.jpg?v=1716499870\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003e2\" Mirror Diagonal with XLT Coatings\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\u003cimg class=\"DAV-img-box\" alt=\"2-inch to 1.25-inch Eyepiece Adapter\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/celestron-2-xlt-sct-diagonal-4.jpg?v=1716499870\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003e2\" to 1.25\" Adapter\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\u003cimg class=\"DAV-img-box\" alt=\"Aluminum Storage Case\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/celestron-2-xlt-sct-diagonal-2.jpg?v=1716499870\"\u003e\n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eAluminum Case\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\u003ca href=\"https:\/\/davidastro.com\/pages\/celestron-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eCelestron 2-Year Warranty\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Celestron","offers":[{"title":"Default Title","offer_id":44967146127645,"sku":"CEL-93527","price":257.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Celestron-2-inch-Mirror-Diagonal-with-XLT-Coatings-93527-1__58186.1594230250.1280.1280.jpg?v=1684337182"},{"product_id":"celestron-45-degree-erect-image-diagonal","title":"Celestron 45-Degree Erect Image Diagonal","description":"\u003cul class=\"DAV-feature-list\"\u003e\n  \u003cli\u003eCorrects image orientation for terrestrial viewing\u003c\/li\u003e\n  \u003cli\u003eProduces right-side-up and left-to-right correct images\u003c\/li\u003e\n  \u003cli\u003eComfortable 45-degree viewing angle for daytime use\u003c\/li\u003e\n  \u003cli\u003eCompatible with refractor and catadioptric telescopes (SCTs, Maks)\u003c\/li\u003e\n  \u003cli\u003eStandard 1.25\" barrel size\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\u003eCelestron 45-Degree Erect Image Diagonal\u003c\/h2\u003e\n          \u003cp\u003eThe Celestron 45-Degree Erect Image Diagonal is the essential accessory for turning your astronomical telescope into a high-power daytime spotting scope. This diagonal uses an Amici prism to provide a correctly oriented, right-side-up and left-to-right image, making it indispensable for terrestrial observation, all backed by a 2-Year Warranty.\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\u003eCorrecting Your View for Terrestrial Observation\u003c\/h3\u003e\n          \u003cp\u003eA standard star diagonal renders images upside-down or mirrored, which is disorienting for terrestrial viewing. The Celestron 45-Degree Erect Image Diagonal solves this by reorienting the light path. Simply swap it with your telescope's standard diagonal to see the world as it is—right-side up and dimensionally correct—making it easy to track birds, boats, or distant landscapes.\u003c\/p\u003e\n        \u003c\/div\u003e\n      \u003c\/div\u003e\n      \u003cdiv class=\"DAV-bg-light\"\u003e\n        \u003cdiv class=\"DAV-section\"\u003e\n          \u003ch3\u003eThe 45-Degree Advantage for Refractors and SCTs\u003c\/h3\u003e\n          \u003cp\u003eThe 45-degree viewing angle is specifically designed for comfort during terrestrial observing, when your telescope is often aimed horizontally. This diagonal is fully compatible with any refractor or Schmidt-Cassegrain (SCT) telescope that uses a standard 1.25\" focuser or visual back.\u003c\/p\u003e\n          \u003cul\u003e\n            \u003cli\u003e\n              \u003cstrong\u003eAmici Prism Design:\u003c\/strong\u003e Ensures a fully corrected image, unlike standard mirror diagonals that only correct one axis.\n            \u003c\/li\u003e\n            \u003cli\u003e\n              \u003cstrong\u003eDaytime Comfort:\u003c\/strong\u003e The 45-degree angle reduces neck strain when observing subjects on or near the horizon.\n            \u003c\/li\u003e\n            \u003cli\u003e\n              \u003cstrong\u003eImportant Limitation:\u003c\/strong\u003e This diagonal is not intended for Newtonian reflector telescopes. The optical design of a Newtonian will prevent this accessory from producing a fully corrected image.\n            \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\u003e45-Degree Erect Image Diagonal vs. Standard 90-Degree Star Diagonal\u003c\/h3\u003e\n          \u003cp\u003eWhile a 90-degree star diagonal is ideal for astronomy where the telescope points high into the sky, it's less practical for terrestrial use. The key difference lies in the image orientation and viewing angle.\u003c\/p\u003e\n          \u003cul\u003e\n            \u003cli\u003e\n              \u003cstrong\u003eImage Orientation:\u003c\/strong\u003e A standard 90-degree diagonal typically produces an image that is right-side up but reversed left-to-right. The 45-degree erect image diagonal corrects both axes.\n            \u003c\/li\u003e\n            \u003cli\u003e\n              \u003cstrong\u003eViewing Angle:\u003c\/strong\u003e The 45-degree angle of this diagonal is far more natural and comfortable for horizontal viewing than the steep 90-degree angle of a star diagonal.\n            \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\"\u003eWhy do I need a 45-Degree Erect Image Diagonal for birdwatching with my SCT?\u003c\/h3\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion-A\"\u003e\n      \u003cp\u003eWithout an erect image diagonal, the view through your Schmidt-Cassegrain telescope will be either upside-down or mirror-reversed. This makes tracking a moving bird nearly impossible. The Celestron 45-Degree Erect Image Diagonal corrects the view to be right-side up and left-to-right correct, just like looking through binoculars.\u003c\/p\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n      \u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use the Celestron 45-Degree Diagonal for astronomy?\u003c\/h3\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion-A\"\u003e\n      \u003cp\u003eWhile you can, it's not ideal. The Amici prism design has a slight ridge in the center that can cause a faint spike on very bright objects like planets or bright stars. For the highest-contrast astronomical views, a dedicated 90-degree mirror or prism star diagonal is recommended.\u003c\/p\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n      \u003ch3 class=\"DAV-accordion-Q\"\u003eWill this 45-Degree Erect Image Diagonal work on my Newtonian reflector telescope?\u003c\/h3\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion-A\"\u003e\n      \u003cp\u003eNo. Due to the optical design of Newtonian reflectors, this diagonal will not produce a fully corrected image. The image orientation will still be rotationally off, and you may not be able to reach focus. This accessory is designed exclusively for refractors and catadioptric telescopes like SCTs and Maksutov-Cassegrains.\u003c\/p\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n      \u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Celestron 45-Degree Diagonal hard to install on my telescope?\u003c\/h3\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion-A\"\u003e\n      \u003cp\u003eInstallation is simple. You just remove your existing 1.25\" diagonal from the telescope's focuser or visual back by loosening the thumbscrews, and then insert the 45-Degree Erect Image Diagonal in its place and tighten the screws. It takes only a few seconds.\u003c\/p\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n      \u003ch3 class=\"DAV-accordion-Q\"\u003eWhat's the main benefit of the 45-degree angle over a 90-degree angle?\u003c\/h3\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion-A\"\u003e\n      \u003cp\u003eFor terrestrial viewing, your telescope is typically horizontal. The 45-degree angle allows you to look down into the eyepiece comfortably. A 90-degree angle would force you to bend over at an awkward angle to see through the eyepiece when the telescope is aimed at the horizon.\u003c\/p\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion\"\u003e\n      \u003ch3 class=\"DAV-accordion-Q\"\u003eI have a Celestron refractor. Will this diagonal allow me to read a sign across the street?\u003c\/h3\u003e\n    \u003c\/div\u003e\n    \u003cdiv class=\"DAV-accordion-A\"\u003e\n      \u003cp\u003eYes, absolutely. A standard diagonal would show the text reversed as if in a mirror. The Celestron 45-Degree Erect Image Diagonal will present the text correctly, making it readable. This is a perfect example of what this accessory is designed for.\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\u003eViewing Angle\u003c\/td\u003e\n          \u003ctd\u003e45 Degrees\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003ePrism Type\u003c\/td\u003e\n          \u003ctd\u003eAmici Roof Prism\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eImage Orientation\u003c\/td\u003e\n          \u003ctd\u003eErect and Correct Left-to-Right\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eBarrel Size\u003c\/td\u003e\n          \u003ctd\u003e1.25\"\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eCompatibility\u003c\/td\u003e\n          \u003ctd\u003eRefractors and Schmidt-Cassegrain \/ Maksutov-Cassegrain Telescopes\u003c\/td\u003e\n        \u003c\/tr\u003e\n        \u003ctr\u003e\n          \u003ctd\u003eWarranty\u003c\/td\u003e\n          \u003ctd\u003e2-Year Warranty\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\"\u003eCelestron 45-Degree Erect Image Diagonal - 1.25\"\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\"\u003eDust Caps\u003c\/p\u003e\n          \u003cp class=\"DAV-item-subtitle\"\u003e× 2\u003c\/p\u003e\n        \u003c\/div\u003e\n      \u003c\/li\u003e\n    \u003c\/ul\u003e\n  \u003c\/li\u003e\n  \u003cli\u003e\n    \u003cul class=\"DAV-grid\"\u003e\n    \u003c\/ul\u003e\n  \u003c\/li\u003e\n  \u003cli\u003e\n    \u003ca href=\"https:\/\/davidastro.com\/pages\/celestron-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eCelestron 2-Year Warranty\u003c\/a\u003e\n  \u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Celestron","offers":[{"title":"Default Title","offer_id":44967146193181,"sku":"CEL-94112-A","price":62.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Celestron-45-Degree-Erect-Image-Diagonal-94112-A-1__59001.1594230251.1280.1280.jpg?v=1684337189"},{"product_id":"celestron-dielectric-star-diagonal-with-twist-lock-1-25","title":"Celestron Dielectric Star Diagonal with Twist-Lock - 1.25\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eOver 99% reflectivity from 58-layer dielectric mirror coatings\u003c\/li\u003e\n\u003cli\u003e1.25” Twist-Lock holder provides a secure, self-centering grip\u003c\/li\u003e\n\u003cli\u003eDiffraction-limited optics maintain your telescope's image quality\u003c\/li\u003e\n\u003cli\u003eMachined aluminum housing with glare-threaded interior\u003c\/li\u003e\n\u003cli\u003eAccepts standard 1.25\" eyepiece filters\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\u003eCelestron Dielectric Star Diagonal, 1.25” with Twist-Lock\u003c\/h2\u003e\n\u003cp\u003eThe Celestron Dielectric Star Diagonal, 1.25” with Twist-Lock, upgrades your telescope's optical train with a diffraction-limited BK7 mirror featuring 58 layers of dielectric coatings. These coatings achieve over 99% reflectivity, ensuring maximum light transmission for brighter, higher-contrast images. The diagonal weighs just 7.5 oz (212.6 g) and is housed in a durable, machined aluminum body measuring 4.5\" x 2\" x 3.5\".\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\u003e99% Reflectivity from 58-Layer Dielectric Coatings\u003c\/h3\u003e\n\u003cp\u003eThe core of this diagonal is its BK7 mirror, which is coated with 58 layers of dielectric material to achieve over 99% reflectivity across the visual spectrum. Unlike standard aluminum or silver coatings that can degrade over time, these dielectric layers are highly durable and deliver consistently bright and sharp images. This ensures that the maximum amount of light collected by your telescope reaches your eyepiece, which is critical for observing faint deep-sky objects and resolving fine planetary detail.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-bg-light\"\u003e\n\u003cdiv class=\"DAV-section\"\u003e\n\u003ch3\u003eThe 1.25\" Twist-Lock Eyepiece Holder\u003c\/h3\u003e\n\u003cp\u003eA significant upgrade from traditional thumbscrew holders, the Twist-Lock mechanism provides a secure, perfectly centered grip on any 1.25\" eyepiece. A simple twist of the orange ring tightens a single compression ring, locking the eyepiece in place without scratching or marring its barrel. This self-centering action guarantees optimal opto-mechanical alignment, preserving the sharpness your telescope is capable of. An integrated barrel stop also prevents accessories with long barrels from making contact with the diagonal's mirror.\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\u003eCelestron Dielectric vs. Standard Diagonals: A Brighter Image\u003c\/h3\u003e\n\u003cp\u003eA star diagonal is a critical component, and a lower-quality one can dim the view and degrade image quality. Standard aluminum diagonals typically offer 88-92% reflectivity, meaning a significant portion of the light from your telescope never reaches your eye. The Celestron Dielectric Star Diagonal, with its over 99% reflectivity, delivers a visibly brighter image. This upgrade alone can make the difference between detecting a faint galaxy's spiral arms or resolving subtle cloud bands on Jupiter.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMachined Aluminum Construction:\u003c\/strong\u003e The black anodized aluminum housing is built for durability and rigidity, preventing flexure that can misalign optics.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGlare Control:\u003c\/strong\u003e The interior of the 1.25\" barrel is both glare-threaded and painted flat black to absorb stray light, maximizing image contrast.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFilter Compatibility:\u003c\/strong\u003e The barrel is threaded to accept standard 1.25\" astronomy filters, allowing you to easily enhance views of the Moon, planets, and nebulae.\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\"\u003eHow will the Celestron Dielectric Star Diagonal improve views of Jupiter through my 8\" SCT?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAn 8\" SCT gathers a lot of light, and you want as much of it as possible to reach your eye. With over \u003cstrong\u003e99% reflectivity\u003c\/strong\u003e, this diagonal transmits more light than a standard one, making Jupiter's cloud belts and Great Red Spot appear brighter and with higher contrast. The diffraction-limited optics ensure you're seeing the full detail your telescope can resolve.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eIs the Twist-Lock holder on this diagonal secure enough for heavy 1.25\" eyepieces?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. The Twist-Lock mechanism uses a \u003cstrong\u003esingle compression ring\u003c\/strong\u003e that applies even, firm pressure around the entire eyepiece barrel. This provides a more secure grip than a single thumbscrew, making it ideal for holding heavier, multi-element 1.25\" eyepieces, even when the telescope is pointed at the zenith.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the Celestron 1.25\" Dielectric Diagonal work with my refractor telescope?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. This diagonal is designed for any telescope with a 1.25\" focuser or visual back, including refractors, Schmidt-Cassegrains (SCTs), and Maksutov-Cassegrains (MCTs). It provides a more comfortable 90° viewing angle, which is especially useful for refractors when observing objects high in the sky.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the advantage of 58-layer dielectric coatings over standard aluminum?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eDielectric coatings are more reflective (over 99% vs. ~92% for enhanced aluminum) and far more durable. They are highly resistant to oxidation and cleaning, meaning the diagonal will maintain its peak brightness and contrast for many years, unlike aluminum coatings which can tarnish over time.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use 1.25\" filters with the Celestron Dielectric Star Diagonal?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes, the 1.25\" nosepiece of the diagonal is threaded to accept standard 1.25\" eyepiece filters. You can easily attach a Moon filter, a light pollution filter, or colored planetary filters before inserting the diagonal into your telescope's focuser.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does \"diffraction-limited\" optical quality mean for this diagonal?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eIt means the mirror surface is smooth and accurate enough that it does not introduce any perceptible degradation to the image formed by the telescope. A diffraction-limited diagonal will pass the light through without adding aberrations, preserving the finest details your main optics can resolve.\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\u003eDiagonal Size\u003c\/td\u003e\n\u003ctd\u003e31.75mm (1.25\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDiagonal Type\u003c\/td\u003e\n\u003ctd\u003eMirror\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGlass Material\u003c\/td\u003e\n\u003ctd\u003eBK7\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCoatings\u003c\/td\u003e\n\u003ctd\u003eDielectric, 58 layers\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReflectivity\u003c\/td\u003e\n\u003ctd\u003eOver 99%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Quality\u003c\/td\u003e\n\u003ctd\u003eDiffraction limited\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEyepiece Holder\u003c\/td\u003e\n\u003ctd\u003e1.25\", Twist-Lock\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompression Ring\u003c\/td\u003e\n\u003ctd\u003eYes, single ring\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHousing Construction\u003c\/td\u003e\n\u003ctd\u003eMachined aluminum, black anodized\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBarrel Interior\u003c\/td\u003e\n\u003ctd\u003eGlare threaded and painted flat black\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Threads\u003c\/td\u003e\n\u003ctd\u003eYes, 1.25\"\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e114.3mm x 50.8mm x 88.9mm (4.5\" x 2\" x 3.5\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e7.5 oz (212.6 g)\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\"\u003e1.25” Dielectric Star Diagonal with Twist-Lock\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\"\u003e1.25\" Barrel Dust Cap\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\"\u003e1.25\" Eyepiece Holder Dust Cap\u003c\/p\u003e\n\u003cp class=\"DAV-item-subtitle\"\u003e× 1\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cul class=\"DAV-grid\"\u003e\n\u003cli class=\"DAV-grid-item\"\u003e\u003ca href=\"https:\/\/www.celestron.com\/pages\/drivers-and-software\" target=\"_blank\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 640 512\" class=\"DAV-img-box\"\u003e\u003cpath fill=\"#0047a7\" d=\"M128 32C92.7 32 64 60.7 64 96l0 256 64 0 0-256 384 0 0 256 64 0 0-256c0-35.3-28.7-64-64-64L128 32zM19.2 384C8.6 384 0 392.6 0 403.2C0 445.6 34.4 480 76.8 480l486.4 0c42.4 0 76.8-34.4 76.8-76.8c0-10.6-8.6-19.2-19.2-19.2L19.2 384z\"\u003e\u003c\/path\u003e\u003c\/svg\u003e \n\u003cdiv\u003e\n\u003cp class=\"DAV-item-title\"\u003eDownload Software\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/davidastro.com\/pages\/celestron-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eCelestron 2-Year Warranty\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Celestron","offers":[{"title":"Default Title","offer_id":44967146258717,"sku":"CEL-93571","price":222.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/products\/Celestron-Dielectric-Star-Diagonal-1-25-inch-with-Twist-Lock-93571-1__79941.1594230252.1280.1280.jpg?v=1684337198"},{"product_id":"celestron-dielectric-star-diagonal-with-twist-lock-2","title":"Celestron Dielectric Star Diagonal with Twist-Lock - 2\"","description":"\u003cul class=\"DAV-feature-list\"\u003e\n\u003cli\u003eDelivers over 99% reflectivity with 58 layers of dielectric coatings\u003c\/li\u003e\n\u003cli\u003eSecure, self-centering Twist-Lock mechanism for 2\" and 1.25\" eyepieces\u003c\/li\u003e\n\u003cli\u003eIncludes interchangeable 2\" and SCT barrels for universal telescope compatibility\u003c\/li\u003e\n\u003cli\u003eDiffraction-limited optics ensure maximum image sharpness\u003c\/li\u003e\n\u003cli\u003eMachined aluminum housing with glare-threaded interior for high contrast\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\u003eCelestron Dielectric Star Diagonal, 2” with Twist-Lock\u003c\/h2\u003e\n\u003cp\u003eThe Celestron Dielectric Star Diagonal, 2” with Twist-Lock, is an essential upgrade for maximizing your telescope's optical performance. Its diffraction-limited BK7 mirror is treated with 58 layers of advanced dielectric coatings to achieve over 99% reflectivity, ensuring the brightest possible images reach your eyepiece. This 19 oz (538.6 g) diagonal provides a secure, perfectly centered connection for both 2\" and 1.25\" eyepieces via its non-marring Twist-Lock holders. With interchangeable barrels for both standard 2\" focusers and Schmidt-Cassegrain telescopes, it offers premium optical and mechanical quality for nearly any instrument.\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\u003e99%+ Reflectivity: 58-Layer Dielectric Coatings\u003c\/h3\u003e\n\u003cp\u003eThe core of this diagonal is a precision BK7 mirror engineered to be diffraction-limited, meaning it will not introduce any perceptible aberrations to the light path. This optical precision is protected by 58 layers of dielectric coatings, which push its light-gathering power to the theoretical maximum. With over 99% reflectivity, you lose virtually no light, resulting in visibly brighter images, higher contrast on faint deep-sky objects, and more vibrant planetary detail compared to standard aluminum or silver diagonals.\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\u003eDual Twist-Lock Holders: Scratch-Free Clamping for 2\" and 1.25\" Eyepieces\u003c\/h3\u003e\n\u003cp\u003eCelestron replaces traditional thumbscrews with a superior Twist-Lock mechanism on both the main 2\" holder and the included 1.25\" step-down adapter. A simple twist of the orange anodized ring activates an internal compression ring that applies uniform pressure, perfectly centering the eyepiece in the optical path. This system not only provides a more secure hold but also guarantees that the barrels of your valuable eyepieces will never be scratched or scored.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMachined Construction:\u003c\/strong\u003e The housing is built from black anodized, machined aluminum for durability and stray light control.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInternal Safety:\u003c\/strong\u003e An integrated stop within the 2\" barrel prevents long-barreled eyepieces or accessories from hitting the mirror surface.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGlare Reduction:\u003c\/strong\u003e The interior of the barrels are glare-threaded and painted flat black to absorb off-axis reflections and maximize image contrast.\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\u003e2 Included Barrels: Universal Fit for Refractors and SCTs\u003c\/h3\u003e\n\u003cp\u003eThis diagonal is designed for immediate use on the two most common telescope types without requiring additional adapters. It includes two interchangeable barrels that thread securely onto the main diagonal housing for a rigid, flex-free connection. One barrel is a standard 2\" nosepiece for refractors and other telescopes with 2\" focusers, while the other is a dedicated SCT adapter for direct, threaded attachment to the rear cell of a Schmidt-Cassegrain. Both the 2\" barrel and the 1.25\" adapter are threaded to accept standard 2\" filters.\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\u003eCelestron Dielectric vs. Standard Aluminum Diagonals: A Worthy Upgrade\u003c\/h3\u003e\n\u003cp\u003eWhile a standard aluminum diagonal is a functional accessory, it represents a significant bottleneck in the optical chain. The Celestron Dielectric Diagonal is a direct, measurable upgrade in two key areas.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLight Throughput:\u003c\/strong\u003e A standard enhanced aluminum diagonal typically reflects 90-92% of light. The Celestron Dielectric's 99%+ reflectivity delivers a noticeably brighter image, which can be the difference between detecting a faint spiral arm on a galaxy or missing it entirely.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDurability:\u003c\/strong\u003e Dielectric coatings are far more durable than aluminum coatings. They will not degrade over time from exposure to the elements, ensuring your diagonal maintains its peak performance for years of use.\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 makes the Celestron 2” Dielectric Diagonal with Twist-Lock superior to a standard diagonal?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Celestron Dielectric Diagonal offers two main advantages. First, its \u003cstrong\u003e58-layer dielectric coatings\u003c\/strong\u003e provide over 99% reflectivity, delivering a significantly brighter image than standard aluminum diagonals (which are typically 90-92% reflective). Second, the \u003cstrong\u003eTwist-Lock holder\u003c\/strong\u003e provides a more secure, perfectly centered grip on your eyepieces without the risk of scratching the barrel, unlike traditional thumbscrews.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eHow do I attach the Celestron Dielectric Diagonal to my Schmidt-Cassegrain telescope (SCT)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eUnscrew the standard 2\" barrel from the diagonal's body and replace it with the included \u003cstrong\u003eSCT adapter barrel\u003c\/strong\u003e. This allows you to thread the entire diagonal directly onto the rear cell threads of your SCT for the most secure connection possible, eliminating any potential for sag or misalignment.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWill the \u0026gt;99% reflectivity of this Celestron diagonal make a visible difference on faint objects like the Veil Nebula (NGC 6960)?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eYes. For faint, extended objects like the Veil Nebula (NGC 6960) or the Horsehead Nebula (Barnard 33), maximizing light throughput is critical. The jump from ~92% to over 99% reflectivity means more photons are reaching your eye, which can significantly improve contrast and make it easier to see delicate structures, especially when using nebula filters.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat is the advantage of the Twist-Lock holder on the Celestron diagonal over traditional thumbscrews?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eThe Twist-Lock mechanism uses a compression ring to apply even pressure around the entire eyepiece barrel. This offers three benefits: it \u003cstrong\u003eperfectly centers the eyepiece\u003c\/strong\u003e in the optical path, it provides a \u003cstrong\u003emore secure grip\u003c\/strong\u003e than a single screw point, and it \u003cstrong\u003ewill not scratch or mar\u003c\/strong\u003e the finish of your eyepiece barrels.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eCan I use my 1.25” eyepieces and filters with this 2” Celestron diagonal?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003eAbsolutely. The diagonal includes a \u003cstrong\u003e2\" to 1.25\" step-down adapter\u003c\/strong\u003e that also features the secure Twist-Lock mechanism. The 1.25\" adapter itself is threaded to accept standard 2\" filters, so you can use your 2\" filters with your 1.25\" eyepieces.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion\"\u003e\n\u003ch3 class=\"DAV-accordion-Q\"\u003eWhat does 'diffraction limited' mean for the Celestron Dielectric Star Diagonal?\u003c\/h3\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"DAV-accordion-A\"\u003e\n\u003cp\u003e\"Diffraction limited\" is a term for optical quality, indicating that the mirror is so precisely figured that any remaining imperfections are smaller than the theoretical limit of resolution imposed by the physics of light (the Airy disk). In practical terms, it means the diagonal will transmit the image from your telescope without degrading its sharpness or detail.\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 colspan=\"2\"\u003e\u003cstrong\u003eOptical Specifications\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDiagonal Size\u003c\/td\u003e\n\u003ctd\u003e50.8mm (2\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDiagonal Type\u003c\/td\u003e\n\u003ctd\u003eMirror\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGlass Material\u003c\/td\u003e\n\u003ctd\u003eBK7\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCoatings\u003c\/td\u003e\n\u003ctd\u003eDielectric, 58 layers\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReflectivity\u003c\/td\u003e\n\u003ctd\u003eOver 99%\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOptical Quality\u003c\/td\u003e\n\u003ctd\u003eDiffraction limited\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"2\"\u003e\u003cstrong\u003eMechanical Specifications\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEyepiece Holder\u003c\/td\u003e\n\u003ctd\u003e2\", Twist-Lock\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2\"-to-1.25\" Adapter\u003c\/td\u003e\n\u003ctd\u003eIncluded, Twist-Lock\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompression Ring\u003c\/td\u003e\n\u003ctd\u003eYes, dual rings for 2\" holder, single for 1.25\" adapter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHousing Construction\u003c\/td\u003e\n\u003ctd\u003eMachined aluminum, black anodized\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIncluded Barrels\u003c\/td\u003e\n\u003ctd\u003e2\" barrel and SCT adapter barrel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBarrel Interior\u003c\/td\u003e\n\u003ctd\u003eGlare threaded and painted flat black\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFilter Threads\u003c\/td\u003e\n\u003ctd\u003eYes, on 2\" barrel and 1.25\" adapter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"2\"\u003e\u003cstrong\u003ePhysical Specifications\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e152.4mm x 76.2mm x 101.6mm (6\" x 3\" x 4\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e19 oz (538.6 g) (with stepdown adapter)\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\"\u003eDielectric Star Diagonal, 2\"\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\" Barrel\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\"\u003eSCT Adapter Barrel\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\" to 1.25\" Twist-Lock 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\u003cli\u003e\n\u003ca href=\"https:\/\/davidastro.com\/pages\/celestron-warranty-policy\" rel=\"noopener\" target=\"_blank\"\u003eCelestron 2-Year Warranty\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Celestron","offers":[{"title":"Default Title","offer_id":44967146291485,"sku":"CEL-93573","price":361.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0753\/5280\/1565\/files\/Celestron-Dielectric-Star-Diagonal-2-inch-with-Twist-Lock-93573-1__81338.1594230253.1280.1280.jpg?v=1684337200"}],"url":"https:\/\/davidastro.com\/en-us\/collections\/celestron-diagonals.oembed","provider":"David Astro","version":"1.0","type":"link"}