The SVBONY SV193 0.8× Focal Reducer / Field Flattener is purpose-designed for the SV503 102mm ED refractor, optimising the telescope for wide-field astrophotography. By reducing focal length and flattening the image field, it delivers sharper stars across the frame and enables faster, more efficient imaging.

Key Features

• 0.8× Focal Reduction
  Shortens the effective focal length by 20%, providing a wider field of view and improving framing of large deep-sky objects.
• Improved Field Flatness
  Corrects field curvature to maintain star sharpness from centre to edge, particularly beneficial for modern camera sensors.
• Optimised for SV503 102ED
  Specifically matched to the optical characteristics of the SV503 102mm ED refractor for best performance and spacing.
• High-Quality Multi-Coated Optics
  Multi-coated lens elements reduce aberrations and reflections, preserving contrast and image clarity.
• Robust Mechanical Construction
  Precision-machined aluminium body with a hard-anodised finish ensures durability and stable spacing during long imaging sessions.

0.8× Photo Reducer / Field Flattener

The 0.8× reduction effectively converts the SV503 102ED from f/7 to approximately f/5.6, allowing shorter exposure times and improved signal collection for astrophotography.

3-Element, 2-Group Optical Design

The three-element, two-group optical layout is engineered to flatten the naturally curved field of refractor telescopes while maintaining good colour correction and edge performance.

Hard-Anodised Aluminium Construction

The rigid aluminium housing features a hard-anodised finish, providing mechanical stability and resistance to wear during repeated setup and long imaging sessions.

Mechanical Structure & Installation

The SV193 integrates directly into the imaging train, allowing secure connection with cameras and accessories. Correct spacing and solid mechanical connections are essential to achieve optimal edge performance.

Backfocus & Camera Compatibility

Accurate backfocus spacing between the reducer/flattener and the camera sensor is critical for achieving flat, well-corrected stars across the image. Performance may vary depending on camera type and adapters used.

• Compatible with dedicated astronomy cameras
• Suitable for DSLR and mirrorless cameras with correct adapters
• Supports standard 2-inch filter systems

Designed for Astrophotography

By reducing field curvature and improving illumination uniformity, the SV193 enables cleaner star shapes and more consistent results across the sensor, making it ideal for imaging nebulae, star fields, and extended deep-sky targets.

Compatibility Notes

• Designed specifically for the SV503 102mm ED refractor
• Not guaranteed to deliver optimal results on other telescope models
• Best performance achieved with precise spacing and rigid imaging trains