Starizona HyperStar V4 for Celestron 11"

From f/10 to a 25x Faster f/1.9 Imaging System

The core function of the HyperStar 11 is to radically increase the light-gathering speed of your Celestron 11" SCT. By operating at a focal ratio of f/1.9, the system becomes approximately 25 times faster than the telescope's native f/10 configuration. This dramatic reduction in exposure time is the single most significant advantage of prime-focus imaging.

Short sub-exposures make tracking errors far less critical, which is why no guiding and no equatorial wedge are required, including on alt-azimuth fork mounts.

A 540mm Focal Length with a 3.7° Coma-Free Field

The HyperStar 11 lens assembly reduces the C11's focal length to 540mm, transforming it into a powerful wide-field instrument. This optical configuration produces a vast field of view up to 3.7° across, allowing you to frame enormous targets like the Andromeda Galaxy (M31) or the entire Veil Nebula complex in a single shot.

Starizona's fully multi-coated optics deliver a coma-free, flat field for sensors up to 35mm in diagonal, which covers APS-C cameras (a full-frame sensor, about 43mm diagonal, is larger).

C11 & EdgeHD 11 Fastar Compatibility

The HyperStar V4 is designed for any Fastar-compatible Celestron 11" Schmidt-Cassegrain telescope. These models feature a secondary mirror that can be unthreaded and removed, allowing the HyperStar lens to be installed in its place. The process is fully reversible, letting you switch between f/1.9 imaging and f/10 visual or planetary work.

• Standard C11 SCT: Mounts directly to any Fastar-compatible C11 optical tube.
• EdgeHD 11: The included EdgeHD Adapter Ring fits the same HyperStar unit to Celestron EdgeHD 11 optical tubes.
• Older Non-Fastar Telescopes: If you have an older C11 without a removable secondary, the HyperStar Conversion Kit (sold separately) allows the telescope to be retrofitted for HyperStar compatibility.

17.5mm Backfocus: Camera Adapters and the Filter Slider Upgrade

At f/1.9, achieving precise camera backfocus is critical for a sharp image across the field. The HyperStar 11 system is designed around a standard 17.5mm backfocus distance, which covers most popular cooled astrocameras.

The standard configuration includes a Standard Camera Adapter with an M42 male top that accepts one 2" (M48) mounted filter. For enhanced flexibility, an optional Filter Slider Upgrade is available. It comes with its own HyperStar Filter Slider Adapter for 17.5mm backfocus cameras and swappable M42 and M54 male top plates.

Installation, Collimation, and Independent Camera Rotation

Switching from visual observing to HyperStar imaging is a straightforward process. The C11's secondary mirror is removed and stored in the included Secondary Mirror Holder, and the HyperStar lens takes its place.

The HyperStar lens features built-in collimation adjustment screws, allowing you to fine-tune the optical alignment. Independent camera rotation lets you frame your target without moving the lens.

Precision Focusing and Mount Balance at f/1.9

The extremely fast f/1.9 focal ratio creates a very narrow critical focus zone, demanding precise focus adjustments. While not difficult, achieving perfect focus requires the right tools. A Bahtinov mask is highly effective, and software-assisted focusing using FWHM (Full-Width Half-Max) measurements with an electronic focuser will yield the best results.

Attaching the 2.1 lb HyperStar and a camera to the front of the telescope shifts the center of balance forward. On a German equatorial mount, you can simply slide the optical tube forward in its cradle to re-balance. However, on a fork-mounted alt-azimuth telescope like a Celestron CPC or Evolution, the HyperStar Counterweight (sold separately) fits into the 1.25" visual back to balance the lens and camera.

HyperStar 11 vs. HyperStar 8: Sensor Size and Field of View

While both the HyperStar 11 and its smaller sibling, the HyperStar 8, convert their respective telescopes to an f/1.9 focal ratio, their intended applications differ based on the telescope's aperture.

• Maximum Sensor Size: The HyperStar 11 offers a significant advantage here, with a 35mm maximum sensor size. The HyperStar 8 is limited to a maximum sensor size of 28mm, making it better suited for APS-C and smaller format cameras.
• Focal Length and Field of View: The HyperStar 11 provides a longer focal length of 540mm compared to the HyperStar 8's 390mm. This gives a larger image scale and a slightly narrower field of view (3.7° vs. 4.1°).