Celestron 1.25" Star Diagonal

Celestron 1.25” Star Diagonal – Comfortable Viewing for Refractor and Catadioptric Telescopes

Enhance your stargazing comfort with the Celestron 1.25” Star Diagonal, an essential accessory for refractor and catadioptric telescope users. This 90º diagonal fits directly into any standard 1.25” focuser, allowing you to observe celestial objects without the awkward neck strain often associated with straight-through viewing.

Ideal for beginners and casual observers alike, this star diagonal provides an easy and affordable way to improve your telescope’s ergonomics and usability.

More Comfortable Observing Angles

Designed to reflect the light path by 90 degrees, this diagonal brings the eyepiece to a more natural and relaxed viewing position—especially helpful when your telescope is pointed at or near the zenith (directly overhead). Say goodbye to uncomfortable bending or craning your neck, and enjoy longer, more enjoyable observing sessions.

Simple Compatibility and Easy to Use

The Celestron 1.25” Star Diagonal is compatible with most refractor and catadioptric telescopes that accept 1.25” accessories. It slides directly into your telescope’s 1.25” focuser and securely holds any standard 1.25” eyepiece. Whether you're observing the Moon, planets, or bright deep-sky objects, this diagonal helps you get the most out of your eyepieces with minimal effort.

Image Orientation

This 90º mirror diagonal delivers images that are right-side up (correct vertical orientation), but the left-to-right orientation will appear reversed. This is typical of star diagonals designed for astronomical use and is not a problem when observing celestial objects, which have no “correct” left-right orientation.

For terrestrial viewing where image orientation is important, you may prefer a 45º erect-image diagonal instead.

Key Features:

• 90º star diagonal for use with 1.25” focusers and eyepieces

• Reflects light to a comfortable viewing angle, reducing neck strain

• Compatible with refractor and catadioptric telescopes

• Displays right-side-up images (mirror-reversed left to right)

• Simple to install and easy to use – perfect for beginners

• Lightweight, compact, and affordable

An Ideal Entry-Level Accessory

If you're just starting out with astronomy or looking to improve the comfort of your viewing setup, the Celestron 1.25” Star Diagonal is an essential addition. It’s a practical, budget-friendly accessory that makes a noticeable difference in how easily and comfortably you observe the night sky.

Order now and enjoy a more relaxed, convenient observing experience.