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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
Baader M68 Extension Tube - 60mm

Baader M68 Extension Tube - 60mm

by Baader Planetarium
SKU BAA-2458206
$111.00 - $111.00
$111.00
$111.00 - $111.00
$111.00
Price Match Policy!
  • Adds a fixed length of spacing to M68 systems
  • M68 female and male threads for a secure, non-flexing connection
  • Matte black interior surfaces reduce internal reflections
  • Integral part of the modular Baader M68 Tele-Compendium system
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • Baader M68 Extension Tube

    The Baader M68 Extension Tube adds a fixed length of rigid, threaded spacing to your imaging train, leveraging the professional M68 system to eliminate flexure. By locking accessories into the large-format M68 thread, this tube ensures perfect optical alignment where standard 2" slip-fit adapters can fail under load.

    The M68 Thread Standard: A Rigid Foundation for Professional Imaging

    Based on the robust M68 thread standard used on large Zeiss telescopes, this system provides a connection with zero play or tilt. For professional-level astrophotography, spectroscopy, or solar imaging with H-alpha systems, eliminating flexure is critical. This extension tube is a core component in building an imaging train that maintains perfect axial alignment, even under the load of heavy cameras and long optical accessories.

    Precision Spacing for Critical Optical Paths

    Complex optical accessories like the Baader Fluorit Flatfield Converter (FFC) or telecentric systems require exact spacing to deliver their specified correction and magnification. This extension tube provides a fixed, repeatable distance within the modular M68 Tele-Compendium system. It allows you to construct a rigid optical train with the precise back-focus required for your specific setup, ensuring sharp, well-corrected results across the field.

    M68 Threaded vs. Slip-Fit: Eliminating Tilt and Flexure

    Standard 2-inch slip-fit adapters, even high-quality versions with compression rings, are a primary source of image shift. The long lever arm created by a heavy camera can cause the entire assembly to sag, ruining alignment and focus. By using a direct M68 threaded connection, this extension tube creates a solid, metal-on-metal lock that physically cannot tilt or shift, preserving the collimation of your entire optical path from the focuser to the sensor.

  • What is the primary use for the Baader M68 Extension Tube?

    This tube is used to add a precise, fixed distance to an imaging or visual train that uses the Baader M68 threaded system. Its primary purpose is to achieve the correct back-focus for accessories like field flatteners, coma correctors, or telecentric systems while preventing any possibility of flexure or tilt.

    Why should I use this Baader M68 tube instead of a standard 2" extension tube?

    A standard 2" extension tube uses a slip-fit connection secured by thumbscrews or a compression ring, which is prone to sagging and tilting under the weight of a camera. The Baader M68 Extension Tube threads directly into other M68 components, creating a single rigid assembly that cannot flex, ensuring perfect optical alignment.

    Is the Baader M68 Extension Tube compatible with T-2 accessories?

    Yes, within the broader Baader M68 system. While this tube itself has M68 threads, Baader produces a wide range of adapters to step down from M68 to the smaller T-2 thread standard. This allows you to securely integrate T-2 accessories into a robust M68 imaging train.

    Will this M68 tube help reduce stray light in my imaging train?

    Yes. The interior of the Baader M68 Extension Tube is carefully blackened with a matte finish to absorb off-axis light. This helps to improve contrast by preventing stray reflections from reaching the sensor, which is especially important in long, complex optical trains.

    How does the Baader M68 Extension Tube prevent my camera from tilting when imaging the Orion Nebula (M42)?

    When you take long exposures of targets like the Orion Nebula (M42), any minuscule tilt in the camera can elongate stars, especially at the edges of the frame. The threaded M68 connection of this tube creates a solid, immovable link between your focuser and camera, completely eliminating the sag and tilt that plague slip-fit adapters, ensuring your stars remain perfectly round.

    Can I stack multiple Baader M68 extension tubes for longer distances on my f/10 SCT?

    Absolutely. These tubes are designed to be modular. You can thread multiple Baader M68 extension tubes of various lengths together to achieve any custom spacing your setup requires. On a long focal length instrument like an f/10 SCT, maintaining this rigidity over a long distance is essential for sharp planetary or deep-sky imaging.

  • Net weight (kg) 0.11
    Compatible Brands Baader Planetarium, Zeiss
    Inner Diameter / Clear Aperture (mm) 62
    Outer Diameter 76
    Type of Adapter Extension
    Optical length (mm) 60
    Usage serves as additional focus distance for eyepiece projection or FFC
    Inner Connection (eyepiece/-camera-sided) M68 x 1
    Outer Connection (lens sided) M68 x 1
    Adapters Family M68 System
  • Baader Planetarium Warranty