SVBONY SV109 M48 Variable Extension Tube is a precision spacing adapter designed for astrophotography imaging trains. With an adjustable length range of 24–35 mm and M48×0.75 threads on both sides, it allows accurate back-focus tuning for cameras, flatteners, and reducers.

Key Features

• Durable anodised aluminium construction
  Manufactured from high-quality aluminium alloy, providing rigidity and low weight for stable imaging setups.
• Internal anti-reflection threading
  Internal threads help suppress stray light and reflections, improving contrast and image clarity during long-exposure imaging.
• Adjustable spacing (24–35 mm)
  Variable length design allows fine tuning of optical spacing to meet the back-focus requirements of flatteners, reducers, and camera sensors.
• M48×0.75 threads on both sides
  Standard M48 threading ensures compatibility with common astrophotography cameras, filter drawers, and optical accessories.
• Solves focusing and spacing issues
  Provides precise control over image train spacing, helping achieve sharp focus and correct image scale.

Design & Adjustment

Separated Components

The extension tube can be separated and adjusted smoothly, allowing precise control over spacing without introducing tilt or misalignment.