DARK CLEAR SKIES · IMAGING ADAPTERS
Connect M54 to M48.
Account for 17.5 mm.
Bring two different threaded connections together while adding a defined spacing distance. The DCS M54 Male to M48 Female Adapter combines an M54 × 0.75 external thread with an M48 × 0.75 internal thread and a specified 17.5 mm back-focus contribution.
Thread conversion and spacing in one component
Choose this adapter when your imaging setup needs to join an M54 × 0.75 female connection to an M48 × 0.75 male connection, with 17.5 mm allowed for the adapter in your spacing calculation.
It can form part of a camera, filter-wheel, filter-drawer or telescope-accessory connection where both interfaces match. The ridged outer collar provides a handhold when fitting or removing the adapter. This is a mechanical connection and spacer, not an optical reducer or Barlow lens.
CHECK BOTH MATING THREADS
The right diameter. The right pitch. The right ends.
| On this adapter | Connects to |
|---|---|
| M54 × 0.75 male | M54 × 0.75 female |
| M48 × 0.75 female | M48 × 0.75 male |
The 0.75 mm pitch applies to both threads. M54 × 1 and M48 × 1 are different fittings. Check the equipment specifications, thread engagement and clearance rather than relying on diameter alone.
Include 17.5 mm in your back-focus calculation
Start with the distance specified for your telescope, reducer or field flattener, measured from its stated reference surface to the camera sensor. Account for the camera’s sensor distance and all other accessories before selecting the remaining spacer length.
WORKED EXAMPLE · NOT A UNIVERSAL REQUIREMENT
55 mm − 37.5 mm = 17.5 mm
A setup requiring 55 mm, with 37.5 mm already accounted for, needs another 17.5 mm. This adapter supplies that specified contribution when the mating threads and clearances are suitable.
The stated 17.5 mm is the back-focus contribution, not a claim about the overall end-to-end length including protruding threads. Follow any filter-related spacing guidance for your optical system and check the assembled distance.
Specifications at a glance
| Brand | Dark Clear Skies |
|---|---|
| Product type | Thread adapter with fixed spacing |
| External thread | M54 × 0.75 mm · male |
| Internal thread | M48 × 0.75 mm · female |
| Specified back-focus length | 17.5 mm |
| Appearance | Black, with Dark Clear Skies branding and ridged outer collar |
| SKU | DCS-M54M-M48F-175 |
Fit by hand and check before use
Keep the components square, start each thread gently and stop if the connection binds. Never force a mismatched fitting. Check that the joints seat correctly, the complete assembly has adequate clearance and the resulting spacing suits your equipment.
What’s included
1 × Dark Clear Skies M54 × 0.75 male to M48 × 0.75 female adapter, with a specified 17.5 mm back-focus contribution. Cameras and other imaging accessories are not included.
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