Airy Disk Flattener / Reducer 0.8x for the 204mm APO

This 0.8x field flattener/reducer is built for the Airy Disk 204mm APO and provides a full-frame 44mm imaging diameter with a 3-element optical design.

It connects to the focuser by M63x1, provides 55mm back focus adjustable to 88mm, and supports camera-side M48x0.75 or M54x0.75 threads. The rear section is removable and includes an M48 filter-thread path, with larger-camera adapter options planned.

Specifications

• Magnification: 0.8x
• Connecting thread: M63x1
• Camera thread: M48x0.75 / M54x0.75
• Image circle: 44.4mm
• Minimum back focus: 55mm
• Maximum back focus: 88.15mm
• Weight: 1kg

Designed for serious astrophotography workflows, the Airy Disk Flattener / Reducer 0.8x for the 204mm APO helps refine field correction, back focus, and imaging performance for compatible Airy Disk refractors. It is a practical upgrade for imagers who want sharper stars, cleaner edge performance, and a more complete telescope imaging system.