Takahashi M72 Male to M48 Male Adapter Ring for CMOS Cameras

The Takahashi M72-M48 adapter for CMOS cameras allows you to connect a camera with an M48 female connector to the FCT-L photographic system. It is shown in the diagrams for the FCT-L 0.8x reducer and the FCT-L 0.99x field corrector for compatible telescopes. This adapter ring serves as the camera-side interface; it is selected based on the camera’s thread and integrates into the assembly using the telescope’s specific CO ring.

Two precisely defined male connectors

On the instrument side, the adapter has an M72 male thread with a pitch of 1 mm. On the camera side, it has an M48 male thread with a pitch of 0.75 mm. Its optical path length is 5.7 mm, and it weighs 49 g. These specifications allow you to identify the mechanical interface shown in the diagrams without confusing it with the M72-M54 adapter, which is designed for cameras that use a different connection.

The starting point for the 55 mm draw

Takahashi specifies that the sensor plane be positioned 55 mm from the base of the camera-side thread on this adapter. This reference point must be maintained when setting up the imaging system. The 5.7 mm specified for the optical path of the ring refers to the adapter itself; it does not alter the location from which the manufacturer defines the distance to the sensor.

In the FCT-L system, the adapter is installed after the CO ring. The FCT-114DF, FCT-114DS, and FC-100DZ use the CO 114D, while the FC-100DF uses the CO 100DF. The FCT-L reducer or corrector is located upstream of this CO ring. The M-mount camera rotator is also included in the documented eyepiece-side configurations, and installing the field corrector requires the M72 L52 extension tube, which is standard on the FCT-114D models and must be purchased separately for the FC-100DZ and FC-100DF models.

The Takahashi design allows for the attachment of a 48 mm filter to the M72-M48 adapter. However, the manufacturer notes that using a filter may cause unwanted reflections and vignetting. Therefore, this mounting option does not guarantee that these effects will not occur in all photographic setups. Please keep the documentation’s disclaimers in mind when selecting related accessories.

This adapter is designed for a CMOS camera with an M48 mount. For an M54 camera, Takahashi offers a separate M72-M54 adapter. For a Canon EF or Nikon F camera body, the system uses an M72 WR adapter and a DX-WR wide-field ring compatible with the mount. These are alternative solutions depending on the camera used; the M72-M48 ring does not replace the other components required to mount the telescope.

Technical specifications

Compatible glasses in the catalog

• Takahashi FCT-114DS – 114 mm fluorite telescope, tube only
• Takahashi FCT-114DF – 114 mm fluorite telescope, tube only
• Takahashi FC-100DZ – 100 mm fluorite telescope with finder scope and mount
• Takahashi FC-100DZ – 100 mm fluorite telescope, tube only
• Takahashi FC-100DF – 100 mm fluorite telescope with finder scope and mount
• Takahashi FC-100DF – 100 mm fluorite telescope, tube only

Technical Documentation

• Takahashi Installation Diagram for the FCT-L Gearhead (PDF)
• Takahashi Installation Diagram for the FCT-L Corrector (PDF)
• Takahashi Technical Presentation on the FCT-L Reducer and Corrector (PDF)

Takahashi's Official Presentation of FCT-L Accessories

Selecting the elements for the montage

• FCT-L 0.8x Focal Length Reducer, sold separately.
• FCT-L 0.99x Field Corrector, sold separately.
• CO 114D for FCT-114DF, FCT-114DS, and FC-100DZ, sold separately.
• CO 100DF for FC-100DF, sold separately.