SVBONY SV209 Focal Reducer/Field Flattener 0.8x for SV550 122F7
This 0.8X focal reducer/field flattener is designed specifically for prime focus astrophotography with the SVBONY SV550 122mm f/7 apo refractor. The fully-multicoated reducer/flattener converts the 854mm focal length f/7 refractor into a 683.2mm f/5.6 system for faster and wider field astronomical and terrestrial photography. In addition to reducing the focal length of the telescope and thereby increasing the photographic speed, the flattens the normal field curvature inherent in refractors.

This provides images that are sharply focused out to the corners of DSLR and CCD imaging chips. The reducer/flattener threads into the focuser for a secure connection. The threading is metric 63x1. Back focus is 55mm from the shoulder of the reducer to the image plane, the standard spacing for DSLR camera bodies.
How To Use
1. SV550 122mm APO Telescope
2. Remove the adapter
3. Connect SV209

Correction of Field Curvature Defects
-- Improving Image Quality At The Edge Of The Field Of View
In addition to reducing the focal length of the telescope and thereby increasing the photographic speed, the flattens the normal field curvature inherent in refractors. This provides images that are sharply focused out to the corners of DSLR and CCD imaging chips.
Fully-Multi-Coated Lens Structure
The fully-multicoated reducer/flattener converts the 854mm focal length f/7 refractor into a 683.2mm f/5.6 system for faster and wider field astronomical and terrestrial photography.
- This 0.8X focal reducer/field flattener is designed specifically for prime focus astrophotography with the SVBONY SV550 122mm f/7 apo refractor.
- The fully-multicoated reducer/flattener converts the 854mm focal length f/7 refractor into a 683.2mm f/5.6 system for faster and wider field astronomical and terrestrial photography
- In addition to reducing the focal length of the telescope and thereby increasing the photographic speed, the flattens the normal field curvature inherent in refractors. This provides images that are sharply focused out to the corners of DSLR and CCD imaging chips
- The reducer/flattener threads into the focuser for a secure connection. The threading is metric 63x1
- Back focus is 55mm from the shoulder of the reducer to the image plane, the standard spacing for DSLR camera bodies