DARK CLEAR SKIES · IMAGING ACCESSORIES
Add 17.5 mm.
Keep your M48 connection.
A fixed extension tube for an M48 × 0.75 imaging train, with a male thread at one end and a female thread at the other.
The DCS M48 × 0.75 Extension Tube – 17.5 mm adds a specified 17.5 mm of spacing between compatible threaded components. Use it when your camera and accessories need additional separation to meet the back-focus requirement of your telescope’s corrector, reducer or flattener.
Three details to match
- Thread size: M48 at both ends.
- Thread pitch: 0.75 mm.
- Added spacing: 17.5 mm.
Build the spacing your setup requires
Camera sensor distance, filter wheels, off-axis guiders and other adapters all contribute to the distance behind a corrector. This fixed-length tube provides a 17.5 mm section within that assembly, while retaining M48 × 0.75 connections.
Check the spacing specified for your exact optical accessory, then account for the components already installed. The 17.5 mm figure describes this tube’s specified back-focus contribution; it is not a complete back-focus requirement for every imaging system.
Check your threads before ordering
The tube’s male M48 × 0.75 end screws into a matching female connection. Its female M48 × 0.75 end accepts a matching male connection. Both the diameter and pitch must match the equipment you are joining.
M42/T2 and M54 connections require suitable adapters. A matching nominal diameter alone does not establish compatibility with a different thread pitch. Check thread clearance and the remaining spacing in your own assembly before use.
Specifications
| Brand | Dark Clear Skies |
|---|---|
| Product type | Fixed threaded extension tube |
| Connections | M48 × 0.75 male to M48 × 0.75 female |
| Specified spacing | 17.5 mm |
| Finish | Black, with Dark Clear Skies branding |
| SKU | DCS-M48-EXT-175 |
What’s included
One DCS M48 × 0.75 extension tube with 17.5 mm specified spacing. Other imaging equipment and any additional adapters are sold separately.
Need another connection or length?
Explore our telescope adapters and extension tubes. If you need help choosing a spacer, tell us the exact components you are connecting and the back-focus distance you need to achieve.