The William Optics 1.25" dielectric star diagonal is designed for refractors and telescopes using Maksutov or Schmidt-Cassegrain optical systems. It provides more comfortable viewing and restores the correct vertical orientation of the image (horizontal mirroring remains). Dielectric coatings form a smoother and significantly more durable surface than aluminum coatings, ensuring maximum brightness, sharpness, and image contrast. The reflectivity reaches 99%, and the mirror is manufactured to a precision of 1/12 lambda.
 
Eyepieces are secured using a clamping ring mechanism.
 
The diagonal is made from aluminum alloys with carbon fiber side plates and features a matte-black interior to suppress internal reflections. It is also equipped with a standard 1.25" filter thread.

Technical specifications / features

• reflectivity: 99%
• mirror surface accuracy: 1/12λ, thickness 12 mm
• clear aperture: 32 mm
• housing: aluminum + carbon fiber plates (metal body with carbon fiber side covers)
• diagonal angle: 90°
• weight: 210 g