DARK CLEAR SKIES · IMAGING ACCESSORIES
M48 × 0.75 extension tube
20 mm spacing
Add a defined 20 mm section to a compatible M48 threaded imaging train.
The DCS M48 × 0.75 Extension Tube – 20 mm adds 20 mm of specified back-focus spacing between compatible threaded components. Use it when your camera and accessories need additional separation to meet the spacing requirement of a corrector, reducer or flattener.
Three details to match
- Thread: M48 × 0.75 at both ends.
- Connections: male at one end and female at the other.
- Added spacing: 20 mm.
Plan the spacing in your imaging train
Camera sensor distance, filter wheels, off-axis guiders and adapters all contribute to the distance behind an optical corrector. Account for those components first, then choose the additional spacing needed for your exact setup.
The 20 mm figure is this tube’s specified back-focus contribution, as stated on its product label. The required total distance depends on your optical accessory and imaging assembly.
Compatibility and fitting
The M48 × 0.75 male end screws into a matching female connection. The M48 × 0.75 female end accepts a matching male connection. Check both the thread diameter and pitch, plus the available thread clearance on the parts being joined.
M42/T2, M54 and other thread sizes require suitable adapters. Choose matching 0.75 mm-pitch M48 connections for direct fitting.
Specifications
| Brand | Dark Clear Skies |
|---|---|
| External connection | M48 × 0.75 male |
| Internal connection | M48 × 0.75 female |
| Specified back-focus spacing | 20 mm |
| Finish | Black, with Dark Clear Skies engraving |
What’s included
One DCS M48 × 0.75 extension tube with 20 mm specified back-focus spacing. Other imaging equipment and additional adapters are sold separately.
Browse our telescope adapters and extension tubes for other connections and lengths. If you need help choosing a spacer, tell us the exact components you want to connect and the spacing you need to achieve.