Description

The Starizona HyperStar 9.25 v4 converts your Celestron 9.25″ Schmidt-Cassegrain from f/10 to a fast f/2.2 imaging system. Like all HyperStar lenses, it replaces the removable Fastar secondary mirror, placing the camera at the front of the telescope for dramatically wider fields and shorter exposures — approximately 20 times faster than native f/10.

The C9.25 uses a unique optical design among Celestron SCTs: its primary mirror operates at f/2.2 rather than f/2, producing an inherently flatter field and a smaller central obstruction. The HyperStar 9.25 v4 takes full advantage of this, delivering a coma-free, flat field of view up to 3 degrees across. The difference between f/2.2 and f/2 is negligible in practice.

The system supports sensors up to 28mm diagonal and is compatible with CCD, CMOS, and DSLR cameras. One camera adapter (threaded for 2″ filters) is included — specify your camera when ordering.

Key Features

Converts Celestron 9.25″ SCT from f/10 to f/2.2 (~20x faster)
Coma-free, flat field of view up to 3°
Supports sensors up to 28mm diagonal
Camera adapter threaded for 2″ filters included
Secondary mirror storage holder included
No spacers needed — adapter sets correct backfocus

Specifications

Focal Ratio	f/2.2
Telescope	Celestron 9.25″ SCT (Fastar-compatible)
Max Sensor Size	28mm diagonal
Field of View	Up to 3°
Filter Thread	2″ (on camera adapter)

Compatibility: Factory Fastar-compatible Celestron 9.25″ SCT only. Older C9.25 models without removable secondary cannot be converted — this is unique to the 9.25″ among SCT sizes.

Explore these guides from our Astro Wiki to learn more about this type of equipment:

Focal Length & F-Ratio → Backfocus & Spacing → Field of View Explained →