{"product_id":"celestron-1-25-dielectric-mirror-diagonal-twist-lock","title":"Celestron Dielectric Star Diagonal 1.25” with Twist-Lock","description":"\u003ch2\u003eCelestron Dielectric Star Diagonal 1.25” with Twist-Lock – Precision Viewing, Maximum Light Transmission\u003c\/h2\u003e\n\u003cp\u003eUnlock the full optical performance of your telescope with the \u003cstrong\u003eCelestron Dielectric Star Diagonal, 1.25” with Twist-Lock\u003c\/strong\u003e. Whether you’re upgrading from a standard diagonal or refining an advanced visual setup, this premium diagonal ensures \u003cstrong\u003ebrighter, sharper, and higher-contrast views\u003c\/strong\u003e—without the cost of a new telescope.\u003c\/p\u003e\n\u003cp\u003eBuilt to deliver maximum light to your eyepiece with minimal distortion, this high-performance 1.25\" diagonal is ideal for \u003cstrong\u003eplanetary, lunar, and deep-sky observations\u003c\/strong\u003e, and is an excellent upgrade for refractor and Schmidt-Cassegrain telescope users.\u003c\/p\u003e\n\u003ch3\u003eWhy Choose a Dielectric Diagonal?\u003c\/h3\u003e\n\u003cp\u003eA star diagonal is more than just a right-angle bend—it's a vital part of the optical system. Poor-quality diagonals can introduce light loss, reduce contrast, and distort your telescope’s image. The \u003cstrong\u003eCelestron 1.25” Dielectric Star Diagonal\u003c\/strong\u003e features a \u003cstrong\u003emirror with over 99% reflectivity\u003c\/strong\u003e, thanks to its \u003cstrong\u003e58-layer dielectric coatings\u003c\/strong\u003e, offering:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eExceptionally bright views\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eDiffraction-limited optical quality\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eNo compromise in image clarity or contrast\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThe dielectric coatings are highly durable and do not degrade over time like traditional aluminium or silver coatings, ensuring \u003cstrong\u003elong-lasting performance\u003c\/strong\u003e with every observing session.\u003c\/p\u003e\n\u003ch3\u003eEnhanced Viewing Comfort \u0026amp; Performance\u003c\/h3\u003e\n\u003cp\u003eThe diagonal reflects incoming light at a 90° angle, providing a \u003cstrong\u003emore natural and comfortable viewing position\u003c\/strong\u003e, especially when observing high-altitude objects. Combined with the \u003cstrong\u003eprecision-polished dielectric mirror\u003c\/strong\u003e, this configuration enhances both \u003cstrong\u003eergonomics and optical fidelity\u003c\/strong\u003e—perfect for extended sessions under the stars.\u003c\/p\u003e\n\u003ch3\u003eTwist-Lock Eyepiece Holder – Secure, Scratch-Free Fit\u003c\/h3\u003e\n\u003cp\u003eForget the frustrations of thumb screws. This diagonal features a \u003cstrong\u003etwist-lock compression ring system\u003c\/strong\u003e that:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eHolds 1.25” eyepieces securely in place\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eKeeps the eyepiece perfectly centred for optimal alignment\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003ePrevents scratches or marring on the eyepiece barrel\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eAn \u003cstrong\u003eintegrated 1.25” barrel stop\u003c\/strong\u003e protects the mirror from accidental contact with long-barrelled accessories, ensuring safe, hassle-free use every time.\u003c\/p\u003e\n\u003ch3\u003ePremium Build Quality, Inside and Out\u003c\/h3\u003e\n\u003cp\u003eCrafted for durability and precision, the diagonal’s body is machined from \u003cstrong\u003eblack anodised aluminium\u003c\/strong\u003e, giving it a rugged yet refined finish. The \u003cstrong\u003eorange anodised twist-lock ring\u003c\/strong\u003e improves visibility in low-light conditions—a thoughtful detail for night-time astronomers.\u003c\/p\u003e\n\u003cp\u003eInternally, the barrel is \u003cstrong\u003eglare-threaded and painted flat black\u003c\/strong\u003e to suppress stray light and reflections, maintaining maximum contrast and image sharpness.\u003c\/p\u003e\n\u003ch3\u003eStandard vs Dielectric Diagonals – See the Difference\u003c\/h3\u003e\n\u003cp\u003eThe difference between a standard and dielectric diagonal can be dramatic. Standard models typically have lower reflectivity and may introduce optical imperfections. In contrast, the \u003cstrong\u003eCelestron Dielectric 1.25” Diagonal\u003c\/strong\u003e delivers:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eOver 99% reflectivity\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eDiffraction-limited optics\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eSuperior image clarity and brightness\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eLasting durability with no degradation in performance\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eEven with a high-quality telescope, using a lower-end diagonal can dull your view. Simply upgrading to this premium dielectric diagonal can result in \u003cstrong\u003enoticeably better visual performance\u003c\/strong\u003e.\u003c\/p\u003e\n\u003ch3\u003eKey Features:\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e1.25” mirror star diagonal with \u003cstrong\u003e58-layer dielectric coatings\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eDelivers \u003cstrong\u003eover 99% reflectivity\u003c\/strong\u003e for maximum light transmission\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eDiffraction-limited optical quality\u003c\/strong\u003e – no loss of image detail\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSecure, scratch-free \u003cstrong\u003etwist-lock compression ring\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eIntegrated \u003cstrong\u003ebarrel stop\u003c\/strong\u003e to protect mirror from long accessories\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eDurable \u003cstrong\u003eblack anodised aluminium body\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eOrange anodised twist-lock ring\u003c\/strong\u003e for night-time visibility\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eInternally \u003cstrong\u003eglare-threaded and flat-black painted\u003c\/strong\u003e to reduce reflections\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eThe Smart Upgrade for 1.25” Eyepiece Users\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003eCelestron Dielectric Star Diagonal, 1.25” with Twist-Lock\u003c\/strong\u003e is an excellent choice for astronomers looking to enhance the visual performance of their telescope setup. Compact, rugged, and optically superior, it’s one of the \u003cstrong\u003ehighest quality 1.25” star diagonals Celestron has ever produced\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cp\u003eWhether you're upgrading from a stock diagonal or building a premium optical train, this accessory will transform your observing experience—\u003cstrong\u003ebrighter views, sharper details, and a more satisfying night under the stars.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eOrder now\u003c\/strong\u003e and see the sky through a clearer lens.\u003c\/p\u003e","brand":"Celestron","offers":[{"title":"Default Title","offer_id":55897345622390,"sku":"050234935715","price":179.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0909\/2235\/3014\/files\/Celestron-Dielectric-Star-Diagonal-1-25-with-Twist-Lock-Product-Photo-1.webp?v=1757493391","url":"https:\/\/welshastronomy.co.uk\/products\/celestron-1-25-dielectric-mirror-diagonal-twist-lock","provider":"The Welsh Astronomy Centre","version":"1.0","type":"link"}