Starizona HyperStar V4 for Celestron 9.25"

The f/2.2 Prime-Focus Corrector for Celestron 9.25" SCTs

The HyperStar is a multi-element lens assembly that mounts in place of your SCT's secondary mirror, converting the telescope to work at the prime focus of its primary mirror. The result is an imaging system that captures faint details in a fraction of the time required at f/10.

This design is intended for deep-sky imagers who want to capture expansive targets like the Andromeda Galaxy (M31) or the North American Nebula (NGC 7000) in a single frame. No guiding and no equatorial wedge are required.

525mm Focal Length at f/2.2: Unguided Imaging with a 3° Field

At f/2.2, the HyperStar 9.25 gathers light far more rapidly than the telescope's native f/10 configuration, so each sub-exposure can be a small fraction of the length needed at f/10.

The optical system produces a coma-free, flat field that supports sensors up to a 28mm diagonal. This generous field of view, spanning up to 3°, is ideal for framing large emission nebulae and galaxy clusters. Short exposures make tracking errors far less critical.

Native Compatibility for all 9.25" Fastar Telescopes (Standard & EdgeHD)

The HyperStar 9.25 is engineered for any Celestron C9.25 Schmidt-Cassegrain telescope equipped with a Fastar-compatible, removable secondary mirror. Unlike the HyperStar 8 and 11, which use an EdgeHD Adapter Ring on EdgeHD tubes, the C9.25 version fits both standard SCT and EdgeHD 9.25 optical tubes natively, with no additional adapter required.

The conversion is reversible: the secondary mirror comes out and the HyperStar lens goes in its place. A protective holder for your secondary mirror is included to keep it safe while you are imaging at f/2.2.

Camera Connections: The 17.5mm Backfocus Standard

The HyperStar 9.25 includes a Standard Camera Adapter with M42 male T-threads, designed for cameras with a 17.5mm backfocus distance. This covers most popular cooled astrocameras. The fast f/2.2 focal ratio makes backfocus critical, which is why the adapters are precisely machined.

For cameras with different backfocus requirements or larger M54 thread sizes, a variety of other adapters are available separately. If you choose the Filter Slider Upgrade, the system includes both M42 and M54 male top plates and is ready for cameras with 17.5mm of backfocus.

Filter Integration: A 2" Threaded Adapter and Optional Filter Slider

The included Standard Camera Adapter accepts one standard 2" (M48) mounted filter, ideal for a broadband, dual-band or IR-cut filter with a one-shot color camera.

For imagers using monochrome cameras or who need to switch between filters rapidly, the optional Filter Slider Upgrade is an essential addition. It uses its own HyperStar Filter Slider Adapter in place of the Standard Camera Adapter and lets you swap filters without touching the camera.

Installation & Collimation: Field-Swapping and Independent Camera Rotation

Switching between f/10 and f/2.2 means exchanging the secondary mirror and the HyperStar lens; the secondary mirror is kept in the included Secondary Mirror Holder while you image.

• Adjustable Collimation: The HyperStar has collimation adjustment screws, allowing you to fine-tune the optical alignment.
• Independent Camera Rotation: Once attached, your camera can be rotated independently of the HyperStar lens. This lets you frame your target without moving the lens.

Balancing the C9.25: Considerations for GEM and Fork Mounts

Adding the HyperStar and a camera, weighing approximately 1.8 lb plus the camera's weight, to the front of the optical tube shifts the telescope's center of balance forward. On a German Equatorial Mount (GEM), this is easily compensated for by sliding the optical tube forward in its saddle.

For fork-mounted alt-azimuth telescopes like the Celestron CPC or Evolution series, the optical tube cannot be repositioned. In this case, the HyperStar Counterweight (sold separately) fits into the 1.25" visual back to balance the lens and camera.

HyperStar 9.25 vs. 8/11: Aperture and the f/2.2 Optical Design

The HyperStar 8 and 11 work at f/1.9, while the HyperStar 9.25 works at f/2.2.

• HyperStar 8 (f/1.9): The 8" model is faster with a shorter 390mm focal length, yielding an even wider 4.1° field of view. The C8 has a smaller aperture.
• HyperStar 11 (f/1.9): The 11" model offers more light-gathering power and a 540mm focal length, and supports larger sensors up to 35mm.
• HyperStar 9.25 (f/2.2): Its 525mm focal length and up to 3° field sit between the HyperStar 8 and 11.

The 1.8 lb Anodized Build: Precision from Tucson, Arizona

The HyperStar 9.25 weighs approximately 1.8 lb, measures 4.2" long (without the camera adapter) and 4.1" in diameter, has a black anodized finish and fully multi-coated optics.

Each HyperStar lens is designed and built by Starizona in Tucson, Arizona.