Baader T-2 Stardiagonal Prism

The Baader T-2 Stardiagonal is a compact 90° prism star diagonal with a large 36 mm BaK4 prism, giving a full 34 mm clear aperture and a short 38.5 mm optical path. Baader recommends it especially for binoviewers with large prisms, and for any set-up where back focus is limited.

The prism is polished to 1/10 wave and coated with Baader's Phantom Coating group plus a sealed BBHS silver back-surface coating, housed in a CNC-milled aluminium body with T-2 threads on both sides so it can be adapted to almost any telescope.

Key Features

• Large 36 mm prism – BaK4 glass prism gives a full 34 mm clear aperture, suited to large-prism binoviewers.
• Short optical path – Only 38.5 mm of light path, ideal where back focus is limited.
• BBHS silver coating – Sealed silver back-surface coating for high reflectivity and long-term durability.
• Precision surfaces – Prism faces are polished to 1/10 lambda, flatter than typical prisms in plastic bodies.
• Modular T-2 system – T-2 thread on both sides lets you build it into the Baader T-2 system with nosepieces and eyepiece holders of your choice (sold separately).
• Sturdy aluminium body – CNC-milled aluminium housing for a solid, compact diagonal.

Specifications