Celestron Dielectric Star Diagonal 1.25” with Twist-Lock

Celestron Dielectric Star Diagonal 1.25” with Twist-Lock – Precision Viewing, Maximum Light Transmission

Unlock the full optical performance of your telescope with the Celestron Dielectric Star Diagonal, 1.25” with Twist-Lock. Whether you’re upgrading from a standard diagonal or refining an advanced visual setup, this premium diagonal ensures brighter, sharper, and higher-contrast views—without the cost of a new telescope.

Built to deliver maximum light to your eyepiece with minimal distortion, this high-performance 1.25" diagonal is ideal for planetary, lunar, and deep-sky observations, and is an excellent upgrade for refractor and Schmidt-Cassegrain telescope users.

Why Choose a Dielectric Diagonal?

A 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 Celestron 1.25” Dielectric Star Diagonal features a mirror with over 99% reflectivity, thanks to its 58-layer dielectric coatings, offering:

• Exceptionally bright views

• Diffraction-limited optical quality

• No compromise in image clarity or contrast

The dielectric coatings are highly durable and do not degrade over time like traditional aluminium or silver coatings, ensuring long-lasting performance with every observing session.

Enhanced Viewing Comfort & Performance

The diagonal reflects incoming light at a 90° angle, providing a more natural and comfortable viewing position, especially when observing high-altitude objects. Combined with the precision-polished dielectric mirror, this configuration enhances both ergonomics and optical fidelity—perfect for extended sessions under the stars.

Twist-Lock Eyepiece Holder – Secure, Scratch-Free Fit

Forget the frustrations of thumb screws. This diagonal features a twist-lock compression ring system that:

• Holds 1.25” eyepieces securely in place

• Keeps the eyepiece perfectly centred for optimal alignment

• Prevents scratches or marring on the eyepiece barrel

An integrated 1.25” barrel stop protects the mirror from accidental contact with long-barrelled accessories, ensuring safe, hassle-free use every time.

Premium Build Quality, Inside and Out

Crafted for durability and precision, the diagonal’s body is machined from black anodised aluminium, giving it a rugged yet refined finish. The orange anodised twist-lock ring improves visibility in low-light conditions—a thoughtful detail for night-time astronomers.

Internally, the barrel is glare-threaded and painted flat black to suppress stray light and reflections, maintaining maximum contrast and image sharpness.

Standard vs Dielectric Diagonals – See the Difference

The difference between a standard and dielectric diagonal can be dramatic. Standard models typically have lower reflectivity and may introduce optical imperfections. In contrast, the Celestron Dielectric 1.25” Diagonal delivers:

• Over 99% reflectivity

• Diffraction-limited optics

• Superior image clarity and brightness

• Lasting durability with no degradation in performance

Even with a high-quality telescope, using a lower-end diagonal can dull your view. Simply upgrading to this premium dielectric diagonal can result in noticeably better visual performance.

Key Features:

• 1.25” mirror star diagonal with 58-layer dielectric coatings

• Delivers over 99% reflectivity for maximum light transmission

• Diffraction-limited optical quality – no loss of image detail

• Secure, scratch-free twist-lock compression ring

• Integrated barrel stop to protect mirror from long accessories

• Durable black anodised aluminium body

• Orange anodised twist-lock ring for night-time visibility

• Internally glare-threaded and flat-black painted to reduce reflections

The Smart Upgrade for 1.25” Eyepiece Users

The Celestron Dielectric Star Diagonal, 1.25” with Twist-Lock 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 highest quality 1.25” star diagonals Celestron has ever produced.

Whether you're upgrading from a stock diagonal or building a premium optical train, this accessory will transform your observing experience—brighter views, sharper details, and a more satisfying night under the stars.

Order now and see the sky through a clearer lens.