Baader M68 Extension Tube - 20mm

Its main purpose is to add a fixed 20mm of length to an optical train while maintaining a rigid, flex-free connection using the M68 thread standard. This is critical for astrophotography setups where mechanical stability is paramount.

Heavy accessories connected via simple slip-fit adapters (like a 2" nosepiece) are prone to tilting under their own weight, which ruins optical alignment. The Baader M68 extension tube replaces that weak link with a solid, threaded connection that physically cannot tilt, ensuring your camera and any other accessories remain perfectly square to the optical axis.

The M68 thread is a large-diameter connection standard, famously used on professional Zeiss telescopes. Its size and robust threading are ideal for supporting heavy imaging trains without any flexure, making it the superior choice for securely connecting modern cameras, filter wheels, and corrective optics.

Yes, it is a modular component of the Baader M68 Tele-Compendium system. This system allows an imager to build a variable-length, rigid adapter and light shield assembly from various M68-threaded tubes and adapters to suit the specific needs of their setup.

Not directly. This tube is designed to be part of a fully M68-threaded optical train. To use it with a standard 2" focuser, you would first need an adapter that converts your focuser's 2" clamp output to a male M68 thread, creating a secure base for the rest of the M68 system.

When used as part of the Tele-Compendium system, the tube's carefully blackened interior walls also function as an effective stray light shield. This helps to block off-axis light from entering the optical path, which significantly improves image contrast, especially when imaging faint objects.