Baader M68 Extension Tube – 80 mm

Baader M68 Extension Tube – 80 mm

Description
The Baader Planetarium M68 – 80 mm extension tube is a precision-engineered mechanical component designed for professional optical setups requiring a significant backfocus increase. In high-end astrophotography and spectroscopy, any mechanical flexure or tilt in the optical train can severely impact image quality or data accuracy.

This risk becomes particularly critical when using long, heavy accessories such as telecentric systems or the Fluorite Flatfield Converter (FFC). These components place high leverage forces on the focuser, and standard slip-fit connections, even with brass compression rings, cannot always guarantee perfect alignment.

By employing an M68 x 1 thread, derived from the high-end Zeiss standard, this extension tube provides a wide and robust screw coupling that eliminates play and tilt while maintaining perfect concentricity. Machined from high-grade aluminium, it features a carefully blackened interior to suppress stray light and ensure maximum contrast.

With its 80 mm optical length, it is ideal for:

• Adjusting backfocus in complex optical trains

• Using an FFC for high-magnification planetary imaging

• Operating a telecentric system with H-alpha filters for solar observation

• Maintaining full compatibility with all M68 and Zeiss threaded accessories

It can be used individually or in combination with other M68 extension tubes to reach the exact required spacing. Its robust design ensures mechanical stability even with heavy accessories.

Fully compatible with the Baader M68 system, it can also connect to other thread standards via optional adapters such as 2.7" Astro Physics, M60 Vixen, and M56 Synta.

Technical specifications

• Manufacturer: Baader Planetarium

• SKU: 2458208

• EAN code: 4047825009937

• Adapter family: M68 system

• Optical length: 80 mm

• Telescope-side external thread: M68 x 1

• Accessory-side internal thread: M68 x 1

• Clear aperture: 62 mm

• Outer diameter: 76 mm

• Weight: 0.14 kg

• Material: precision-machined aluminium

• Internal finish: matte black anti-reflective coating

• Usage: extension for eyepiece projection or FFC

• Compatibility: Baader M68 and Zeiss systems