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Celestron 2" Dielectric Star Diagonal with Twist-Lock - 93573

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SKU: CEL-93573
$208.95 $199.95
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Celestron 2" Dielectric Star Diagonal

  • Combining diffraction-limited optics and dielectric coatings, this premium 2" diagonal significantly improves the views observers experience through a telescope
  • A convenient 90º viewing angle is provided for more comfortable viewing using refractor and Cassegrain-style telescopes
  • Over 99% surface reflectivity thanks to 58 layers of dielectric coatings ensures that the greatest amount of light accumulated by the telescope ends its journey at your eyepiece
  • Inserted eyepieces are kept centered in the diagonal by the twist-lock adapter for better optical alignment
  • Comes with a 1.25" stepdown adapter for compatibility with all 2" and 1.25" barrel eyepieces, Barlow lenses, threaded filters, and other accessories
  • Includes two interchangeable adapters for switching between Schmidt-Cassegrain threads and a 2" barrel adapter, allowing this diagonal to be used with a wide range of telescopes


Upgrade your existing star diagonal to this premium Celestron 2” Dielectric Star Diagonal with Twist-Lock for assured optimal light transmission without any decrease in optical quality. Images seen through your telescope using this diagonal will appear both brighter and sharper. This means you don’t have to purchase a completely new telescope in order to improve your view.

By reflecting the telescope's light path 90º, this star diagonal offers a more convenient viewing angle. Furthermore, with 58 layers of dielectric coatings providing over 99% surface reflectivity, this 2" dielectric diagonal's glass allows the greatest amount of light to reach the eyepiece. And, with the included 1.25" stepdown adapter, this diagonal benefits from being compatible with both larger 2" eyepieces for a wider field of view, as well as standard 1.25" eyepieces.

The twist-lock eyepiece holder secures eyepieces while keeping them centered in the diagonal, thus providing best opto-mechanical alignment between the telescope and eyepiece. Unlike traditional thumb screws, the twist-lock cannot scratch or engrave the barrel of your eyepieces. This diagonal has an integrated 2” barrel stop that prevents 2” accessories with long barrels from damaging the mirror.

Except for the twist lock ring which is orange anodized to enhance visibility, this diagonal’s construction consists of black anodized aluminum. Both the SCT adapter and 2" barrel interior are glare threaded and painted flat black to minimize glare. Taken together, the Celestron 2” Dielectric Star Diagonal’s features and high-end finishes make it one of the best 2” star diagonals ever offered by Celestron in terms of quality.

Two interchangeable barrels are also included with this diagonal to enable the flexibility necessary for connection to a wide range of telescopes without the need for supplemental adapters. A standard 2" barrel is included for telescopes, such as refractors, that accept 2" barrels in their focuser, while an SCT threaded barrel is included for Schmidt-Cassegrain telescopes. Each barrel threads onto the diagonal housing for secure attachment to the diagonal.

Standard Star Diagonals vs Dielectric Star Diagonals

Reflectivity and optical quality are the key specifications for a star diagonal. This dielectric diagonal delivers top performance in both categories, with an over 99% reflective mirror and diffraction-limited optical quality to ensure that virtually all the light collected by the telescope reaches your eyepiece without the diagonal having an impact on optical performance. Using a lower quality star diagonal can both dim the view and degrade optical quality. You can instantly improve the views you experience through your telescope by simply swapping out its diagonal for a premium Celestron Dielectric Star Diagonal.