Astronomy Specialist



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This adapter combines an M54 male thread and M42 male thread (T2) for an overall optical thickness of only 2mm.
On the M54 side, the adapter has an M48 x 0.75 female thread for 2" filters.

Among others, the adapter fits:

  • ATIK EFW filter wheels
  • Lacerta 2" Herschel prism
  • Starlight Xpress filter wheels
  • Focusers with female M54 x 0.75 thread


This adapter is not compatible with SkyWatcher focusers as they have a different thread pitch (M54 x 1).

Telescope connection

Male M54 x 0.75 and female M48 x 0.75

Camera connection

Male M42 x 0.75 (T2)

Length of the M54 thread

5 mm

Length of the M42 thread 4 mm
Optical length
2 mm
Adapter length
11 mm
Internal anti-reflective thread


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