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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.
Baader Adapter 2" SCT(M) Thread/T-2(M)
Baader Adapter 2" SCT(M) Thread/T-2(M)

Baader Adapter 2" SCT(M) Thread/T-2(M)

by Baader Planetarium
SKU BAA-2958242
$39.00 - $39.00
$39.00
$39.00 - $39.00
$39.00
Price Match Policy!
  • Connects T-2 (M42x0.75) accessories to 2" SCT rear threads
  • Adds only 1mm of optical path length to the imaging train
  • Male 2" SCT thread (2"-24 TPI) for direct connection to the telescope
  • Male T-2 thread for universal accessory compatibility
  • Machined for a rigid, non-flexing connection
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • Baader Adapter 2" SCT(M) Thread to T-2(M)

    The Baader Adapter 2" SCT(M) Thread/T-2(M) provides a rigid, secure connection between a standard 2-inch Schmidt-Cassegrain rear cell and the universal T-2 (M42x0.75) thread system. This precision-machined reducer consumes only 1mm of optical length, preserving critical back focus for complex imaging trains.

    Minimal 1mm Optical Length for Demanding Imaging Trains

    When assembling an imaging system with a focal reducer, off-axis guider, and filter wheel, every millimeter of back focus is critical. The Baader 2" SCT to T-2 adapter's ultra-thin 1mm profile is engineered to consume the absolute minimum optical path length, ensuring you have enough travel to achieve a sharp focus.

    Unlike standard visual backs or longer adapters that can use up 10mm or more of your available back focus, this reducer is designed specifically for astrophotography. It provides the most direct and compact coupling possible between your SCT and your T-2 threaded accessories, preventing vignetting and maintaining the integrity of your optical train.

  • What is the primary function of the Baader 2" SCT to T-2 Adapter?

    This adapter's main purpose is to connect accessories using the international T-2 (M42x0.75) thread standard to the larger 2-inch thread found on the rear cell of most Schmidt-Cassegrain Telescopes (SCTs). This allows you to securely attach cameras, filter wheels, and off-axis guiders directly to your telescope.

    Why is the 1mm optical length of this Baader adapter so important?

    The minimal 1mm optical length is critical for astrophotography. SCTs, especially when used with a focal reducer, have a very specific and limited back focus distance required for sharp stars across the field. This ultra-thin adapter consumes almost none of that precious distance, allowing you to fit more accessories like filter wheels and off-axis guiders into your imaging train without being unable to reach focus.

    Can I use this Baader adapter to attach a DSLR to my Celestron 8" SCT?

    Yes. You would thread this adapter directly onto your SCT's 2" rear cell. Then, you attach a T-Ring that is specific to your DSLR brand (e.g., Canon EOS or Nikon F-mount) to this adapter's male T-2 threads. This creates a secure, all-threaded connection for prime-focus astrophotography.

    Will this adapter work with an off-axis guider (OAG) in my SCT imaging train?

    Absolutely. This adapter is an ideal choice for use with an OAG. Its low-profile 1mm design leaves the maximum possible back focus available for the OAG body and the main imaging camera, which makes it much easier to achieve simultaneous focus with both the guide camera and the main camera.

    What accessories can I connect to my SCT using this Baader adapter?

    This adapter allows you to connect any accessory that has a female T-2 (M42x0.75) thread. Common examples include:

    • Astrophotography cameras from brands like ZWO, QHY, etc.
    • DSLR-specific T-Rings for connecting camera bodies.
    • T-2 filter wheels or manual filter drawers.
    • T-2 off-axis guiders (OAGs).
    • T-2 extension tubes for achieving precise spacing.

    Is the 2" SCT thread on this adapter the same as a 2" filter thread?

    No, and this is a critical distinction. This adapter uses the coarse 2" SCT thread (2"-24 TPI) found on the rear cell of most Celestron and Meade SCTs. It is not compatible with the fine M48x0.75 thread used for 2" astronomy filters.

  • Input Thread (Telescope Side) 2" SCT Male (2"-24 TPI)
    Output Thread (Accessory Side) T-2 Male (M42x0.75)
    Optical Length 1 mm
    Net weight (kg) 0.01
    Inner Diameter / Clear Aperture (mm) 41
    Outer Diameter 52
    Type of Adapter Expanding Adapter
    T-2 Part # 28
    Outer Connection (eyepiece/-camera-sided) 2"/SCT Thread (50.8mm)

  • This product is an adapter and does not come with additional accessories.

  • Baader Planetarium Warranty