Skip to content
Price match 30-day returns* Talk to an astronomer before you buy
Baader Celestron Nut - 3.3" SCT Thread
Baader Celestron Nut - 3.3" SCT Thread
Baader Celestron Nut - 3.3" SCT Thread

Baader Celestron Nut - 3.3" SCT Thread

by Baader Planetarium
SKU BAA-2408145
$126.00 USD - $126.00 USD
$126.00 USD
$126.00 USD - $126.00 USD
$126.00 USD
Price Match Policy!
  • Adapts the large 3.3" SCT rear thread (C11, C14) to an S65 dovetail receptor for the Baader 2" Deluxe Eyepiece Clamp
  • Provides a rigid, all-threaded connection for astrophotography
  • Compatible with Celestron C11 and C14 optical tubes
  • Replaces standard visual backs to eliminate potential tilt and flexure
Backordered
Request Stock Alert
Availability Info
Qualifies for FREE Shipping in CONUS on orders over $350.
Vignetting Calculator

Will your imaging train vignette?

Check which filter and adapter sizes clear the sensor with the Baader Celestron Nut - 3.3" SCT Thread, and how much light the corners lose.

Check vignetting
  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • Baader Celestron Nut - 3.3" SCT Thread

    The Baader Celestron Nut securely adapts the large 3.3" rear cell thread found on Celestron C11 and C14 telescopes to an S65 dovetail receptor that holds the Baader 2" Deluxe Eyepiece Clamp (#2408140). This essential component allows you to replace the factory-standard visual back with a solid, threaded connection for building a robust imaging or visual train.

    Holding the Baader 2" Deluxe Eyepiece Clamp on 3.3" SCTs

    This adapter nut holds the Baader 2" Deluxe Eyepiece Clamp (#2408140) on your large-aperture SCT: the clamp sits in the nut's S65 dovetail receptor, directly on the telescope's rear cell. By doing so, you can create a completely customized, rigid optical train tailored to your specific imaging or observation needs.

    Eliminating Flexure: The Baader 3.3" Nut vs. Stock Visual Backs

    For astrophotographers, the primary advantage of this nut is the elimination of flexure. Standard visual backs that rely on thumbscrews to hold a 2" diagonal or camera nosepiece can introduce tilt, especially with heavy equipment. This tilt can lead to elongated stars in the corners of your images. The Baader 3.3" Nut creates a direct metal-on-metal threaded connection that cannot sag or shift during a long exposure, ensuring your entire imaging train remains perfectly aligned with the telescope's optical axis.

  • Which telescopes is the Baader 3.3" Celestron Nut compatible with?

    This adapter is designed for Schmidt-Cassegrain telescopes that use the large 3.3-inch rear cell thread. Examples are the Celestron C11 and C14.

    What does the Baader 3.3" Celestron Nut allow me to connect to my telescope?

    It provides an S65 dovetail receptor that holds the Baader 2" Deluxe Eyepiece Clamp (#2408140) on C11 and C14 telescopes. It has no T-2 thread.

    How does this Baader Nut improve my astrophotography setup compared to the stock visual back?

    The primary benefit is rigidity. A standard visual back uses set screws, which can allow a heavy camera and filter wheel to tilt or sag, causing image defects. The Baader Nut creates a solid, threaded connection that eliminates this flexure, ensuring your camera sensor remains perfectly orthogonal to the light path.

    I have a Celestron C11 and want to use the Baader 2" Deluxe Eyepiece Clamp. Is this the part I need?

    Yes. The Baader 3.3" Celestron Nut threads onto your C11's rear cell, and the 2" Deluxe Eyepiece Clamp (#2408140) is then held in its S65 dovetail receptor. T-2 accessories do not thread into this nut.

    Will this Baader 3.3" Nut work on my Celestron C8 or C9.25?

    No. Celestron C8 and C9.25 telescopes use the smaller, standard 2-inch SCT thread on their rear cells. This nut is specifically for the larger 3.3-inch thread found on the C11 and C14.

  • Net weight (kg) 0.07
    Screw Type 6 x M2 Allen wrench screws
    Compatible Brands UNC, Celestron
    Clamping System Dovetail clamp
    Inner Diameter / Clear Aperture (mm) 58
    Outer Diameter 90
    Type of Adapter Reducing Adapter
    Optical length (mm) 2
    T-2 Part # 18
    Usage to connect the 2" eypiece clamp on C11 and C14 telescopes
    Inner Connection (eyepiece/-camera-sided) S65
    Inner Connection (lens sided) 3.3"/SCT Thread (84.2 mm)
    Adaptable to Celestron C11 / C14

    • Baader Celestron Nut - 3.3" SCT Thread

      × 1

  • Baader Planetarium Warranty