Celestron 45º Erect Image Diagonal

Celestron 45º Erect Image Diagonal – The Perfect Upgrade for Daytime Viewing

Did you know your telescope isn’t just for stargazing? Many refractor and catadioptric telescopes, including popular Schmidt-Cassegrain models, also work exceptionally well for terrestrial observation. To make the most of your telescope during the day, the ideal upgrade is the Celestron 45º Erect Image Diagonal.

This clever accessory corrects image orientation, so what you see through the eyepiece matches the real world—upright and correctly oriented left to right. Whether you’re observing wildlife, scenic landscapes, or distant ships, this diagonal makes daytime use of your telescope intuitive, natural, and enjoyable.

Why You Need an Erect Image Diagonal for Terrestrial Use

Most standard star diagonals used for astronomy produce inverted or mirror-reversed images. While this doesn’t matter for celestial viewing (there’s no "right way up" in space), it can be disorienting when observing land-based objects. Try following a bird in flight or tracking a moving boat with a reversed or upside-down view—it's far from ideal.

The Celestron 45º Erect Image Diagonal solves this by using an Amici prism, which delivers:

• Right-side-up images

• Left-to-right correct orientation

• A comfortable 45º viewing angle—perfect for horizontal or near-horizontal viewing

This makes it an essential addition for anyone who wants to get more use out of their telescope during the day.

Ideal for Refractors and Schmidt-Cassegrain Telescopes

This diagonal is designed for telescopes that accept 1.25” accessories, including:

• Refractor telescopes

• Catadioptric telescopes (like Schmidt-Cassegrains and Maksutovs)

Simply remove your existing star diagonal and replace it with the Celestron 45º erect image diagonal. It slides into the focuser or visual back with ease and is compatible with all standard 1.25” eyepieces.

Important Note for Newtonian Users

Please note that this erect-image diagonal is not suitable for Newtonian reflectors. Due to the internal optical design of Newtonians, adding an erect-image diagonal will not provide a fully correct orientation. While Newtonians can still be used for daytime observing, users will need to become comfortable with images that appear rotationally skewed.

Key Features:

• 45º Amici prism diagonal for comfortable terrestrial viewing

• Produces images that are upright and correctly oriented

• Compatible with 1.25” eyepieces and focusers

• Ideal for refractor and catadioptric telescopes

• Makes tracking moving objects or landscapes intuitive and accurate

• Lightweight, easy to install, and durable

Transform Your Telescope into a Terrestrial Spotting Scope

Whether you're birdwatching, ship spotting, or enjoying panoramic views, the Celestron 45º Erect Image Diagonal makes your astronomical telescope versatile for daytime adventures. It’s a simple, affordable way to get more out of your gear—day or night.

Order now and enjoy crystal-clear, properly oriented daytime views with your telescope.