The Celestron f/6.3 focal reducer is an accessory optimized for Schmidt–Cassegrain telescopes. It reduces the required exposure time and increases the field of view by shortening the telescope’s focal length. It converts f/10 systems to f/6.3 without changing the size of the central obstruction.
This accessory is suitable for both visual observation and astrophotography. For imaging, a sensor distance of approximately 105 mm is recommended.