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Celestron 1.25" Dielectric Mirror Diagonal with Twist-Lock Holder - 93571

Celestron 1.25" Dielectric Mirror Diagonal with Twist-Lock Holder - 93571 - Main image
$97.46 $129.95 In stock

Category: Telescope Accessories

Celestron 1.25" Dielectric Mirror Diagonal

For guaranteed maximum light transmission without compromising on optical quality, the 1.25" Dielectric Star Diagonal with Twist-Lock from Celestron is an excellent choice. Experience images that are both brighter and sharper by upgrading your existing star diagonal to this premium model.

By reflecting the telescope's light path 90º, this star diagonal is able to offer increased viewing comfort. Glass surface is over 99% reflective thanks to 58 layers of dielectric coatings to enable the maximum amount of light to reach the eyepiece. 1.25" eyepieces are kept secure and centered in the diagonal by the twist-lock holder for optimal opto-mechanical alignment between telescope and eyepiece. Twist-lock is unable to scratch or engrave your eyepiece barrel unlike conventional thumb screws. A built-in 1.25" barrel stop protects the mirror from being damaged by 1.25" accessories with long barrels.

The twist lock ring is orange anodized for increased visibility while the remainder of this diagonal’s construction consists of black anodized aluminum. A threaded and flat black painted interior works to prohibit glare. Taken together, the Celestron 1.25” Dielectric Star Diagonal’s features and high-end finishes make it one of the best 1.25” star diagonals ever offered by Celestron in terms of quality.

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.

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Customer Reviews (4.8 / 5 · 5 reviews)

Julian I. ★★★★★

The dielectric coating noticeably improved contrast on Jupiter compared to my old prism diagonal. Views of Saturn's rings were sharper and more defined even at 200x magnification.

Amelia ★★★★★

The twist-lock holder is a game changer—my eyepieces stay rock solid now, no more wobble when I bump the focuser. The dielectric coating really does make the views of Jupiter noticeably brighter and sharper than my old prism diagonal.

Andrew ★★★★★

I’ve been using this diagonal with my 1.25" eyepieces and the dielectric coating really does seem to brighten faint planetary details compared to my old prism.