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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 Planetarium Inverter ring M48a (female to male)
Baader Planetarium Inverter ring M48a (female to male)
Baader Planetarium Inverter ring M48a (female to male)

Baader Planetarium Inverter ring M48a (female to male)

by Baader Planetarium
SKU BAA-2958555
$38.00 - $38.00
$38.00
$38.00 - $38.00
$38.00
Price Match Policy!
  • Converts M48 Female (Internal) Threads to Male (External)
  • Standard M48 x 0.75 Filter Thread Pitch
  • Solves Incompatible Gender Connections in an Optical Train
  • Low-Profile Design Minimizes Added Back Focus
  • Also Serves as a Replacement Part for the Baader FlipMirror II
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • Inverter ring M48a (female to male)

    The Baader Planetarium M48a Inverter Ring is a fundamental problem-solver that converts a female M48 thread into a male M48 thread, resolving critical connection conflicts in an imaging train. This adapter ensures mechanical compatibility between M48 accessories like filter wheels, off-axis guiders, and correctors that would otherwise be unable to connect due to having the same M48 thread gender.

    The M48 Standard: Reversing Thread Gender for Full Compatibility

    As you assemble a complex optical train, it's common to encounter a situation where two components both present a female M48 thread, making a direct connection impossible. The M48a Inverter Ring acts as a gender changer, threading into one of the female ports to present a male M48 thread, allowing the two accessories to be securely coupled.

    • Universal M48 Fit: Machined to precise M48 x 0.75mm filter thread standards, this ring is compatible with M48 accessories from any manufacturer.
    • Minimal Optical Path: Its low-profile design is engineered to add the smallest possible length to the optical train, helping you preserve critical back focus distance.
    • Baader System Component: This ring is included with the Baader FlipMirror II (BFM-II), making it a direct replacement for a lost part or a valuable adapter to have on its own for other applications.

  • What is the main purpose of the Baader M48a Inverter Ring?

    The Baader M48a Inverter Ring is a thread adapter, often called a "gender changer." Its sole function is to convert a female (internal) M48 thread into a male (external) M48 thread. This allows you to connect two pieces of equipment that both have female M48 threads.

    My M48 filter wheel has a female thread, and so does my corrector. How does the M48a Inverter Ring fix this?

    This is the exact scenario the M48a Inverter Ring is designed for. You simply thread the ring into the female M48 port on either your filter wheel or your corrector. The ring now presents a male M48 thread, allowing you to securely connect the two components and complete your imaging train.

    Is the Baader M48a Inverter Ring compatible with all M48 accessories?

    Yes. It is designed to work with the universal M48 x 0.75mm thread pitch, which is the standard for 2-inch astronomical filters and many correctors, flatteners, and camera adapters. It will work with M48 accessories from any brand that adheres to this standard.

    Does this M48a Inverter Ring add significant length to my imaging train?

    No, it is designed to be as low-profile as possible. While it does add a small amount of optical path length, it is typically negligible and unlikely to cause issues with achieving the correct back focus distance for most setups. Its purpose is to solve a mechanical connection problem with minimal optical impact.

    I own a Baader FlipMirror II. Do I need to buy this M48a Inverter Ring separately?

    No, you should not need to. The Baader M48a Inverter Ring is an included component with the Baader FlipMirror II Star Diagonal (BFM-II). This item is offered separately primarily as a replacement for a lost part or for astronomers who need this specific adapter for other parts of their imaging train.

    I am building an imaging train for my refractor with a field flattener. When would I need the M48a Inverter Ring?

    You would need the M48a Inverter Ring if, for example, the telescope-side of your camera has a female M48 thread, and the camera-side of your field flattener *also* has a female M48 thread. This adapter would screw into one of them, converting it to male and allowing the two to connect at the correct spacing.

  • Function Converts M48 Female (Internal) Thread to Male (External)
    Thread Standard M48 x 0.75mm

    • Inverter ring M48a (female to male)

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  • Baader Planetarium Warranty