I have a Starizona SCT Corrector/Reducer for sale. It's in excellent condition and It provides a much improved image circle compared to the Celestron or Meade 0.63x reducer.
Ideal applications are for non HD Celestron SCT's and Pre ACF Meade SCT's.
Optics are perfect no scratched or fungus.
The Starizona SCT Corrector was named one of Sky & Telescope's Hot Products for 2012!
Here are Starizona's specs-The Starizona SCT Corrector is a focal reducer and field flattener for standard Schmidt-Cassegrain telescopes. It converts the telescope from f/10 to f/7.5, resulting in a wider field and faster imaging. f/7.5 is nearly 1.8 times faster than f/10!
The field is optimized for a 35mm image circle. Spot sizes are up to 5 times smaller than the native telescope, and coma is completely eliminated. The result is much sharper stars across a large, flat field of view. A standard 2" mounting allows a variety of telescope attachment options.
The SCT Corrector has 90mm (3.5") of mechanical backfocus, accommodating a large variety of cameras and filter wheels. Spacers are required to set the exact backfocus distance and are available separately for a variety of cameras (see below).
Features
0.75x Focal Reduction
35mm Optimized Image Circle
2" Diameter
90mm Backfocus
Threaded for 2" (48mm) Filters
Fully Multi-Coated Optics
Made in USA
Example Specifications (11" SCT)
Note that since the SCT Corrector is designed to correct the coma inherent in standard Schmidt-Cassegrain telescopes, it will not work properly with Celestron EdgeHD or Meade ACF optical systems.