William Optics 1.25" 90° Erecting Prism Diagonal D-EP90-125II (new version 2019, SKU: D-EP90-125II)

The William Optics 1.25" 90° erecting prism diagonal features a helical focusing barrel for fine adjustment. This is one of the best accessories of its kind – precisely crafted and available exclusively from William Optics. It is an ideal choice for premium refractors, especially for daytime observations, as it provides an erect (non-inverted) image without degrading optical quality.

The diagonal also works perfectly with Maksutov, SCT, Cassegrain, and Ritchey-Chrétien (RC) telescopes.

Technical specifications / features

• type: 90°, 1.25", erecting prism
• high-precision BaK-4 prism with anti-reflection coating and high light transmission
• helical focuser barrel with 15 mm focusing travel
• full metal construction, body and nosepiece black anodized
• internally matte-blackened and threaded surfaces – eliminates stray light reflections
• secure eyepiece clamping with compression ring
• 1.25" filter thread on the eyepiece barrel
• clear aperture: 20.2 mm
• perfect for daytime observations (erect image)
• weight: 180 g