Starizona HyperStar V4 for Celestron 8"

Starizona HyperStar 8: An f/1.9 Prime-Focus Imaging System

The HyperStar 8 lens assembly replaces the secondary mirror on any Fastar-compatible 8" Celestron Schmidt-Cassegrain telescope. This conversion places your camera at the prime focus of the telescope's primary mirror, creating an incredibly fast, wide-field instrument ideal for deep-sky astrophotography. The result is a 390mm f/1.9 system that captures vast targets like the Andromeda Galaxy (M31) or the North American Nebula (NGC 7000) in a single frame.

This design is engineered for imagers who want to capture high-quality data in a fraction of the time required by traditional setups. No guiding and no equatorial wedge are required. The HyperStar V4 is a complete, self-contained optical system designed and built in Tucson, Arizona.

25x Faster Imaging: The f/1.9 Advantage for Unguided Exposures

The defining feature of the HyperStar system is its speed. By converting the C8 from f/10 to f/1.9, the HyperStar 8 is 25 times faster than the stock f/10 telescope, so each sub-exposure can be a small fraction of the length needed at f/10.

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

HyperStar 8 vs. Native f/10: A 25x Speed Comparison

Operating a Celestron 8" SCT in its native f/10 configuration yields a focal length of around 2032mm, ideal for high-magnification views of planets and small deep-sky objects. The HyperStar 8 offers a completely different imaging experience by converting the same telescope into a 390mm f/1.9 astrograph.

• Focal Ratio: f/1.9 with HyperStar versus f/10 natively. That is 25 times faster.
• Field of View: The HyperStar delivers up to a 4.1° field, wide enough to encompass huge emission nebulae and star clusters. The native f/10 field is typically less than one degree, suited for close-ups.
• Focal Length: 390mm with HyperStar versus ~2032mm natively. The short focal length of the HyperStar is far more forgiving of tracking errors and wind, making guiding less critical or even unnecessary.
• Primary Use Case: The HyperStar excels at capturing large deep-sky objects quickly. The native f/10 configuration is superior for imaging the Moon, planets like Jupiter and Saturn, and resolving fine detail in smaller galaxies and planetary nebulae.

A 4.1° Coma-Free Field for Sensors up to 28mm

The HyperStar V4 optics are engineered to deliver a flat, coma-free image circle across a field of view up to 4.1° wide. The fully multi-coated lens system corrects the image at the prime focus of the Schmidt-Cassegrain for a coma-free, flat field.

The system is optimized for modern astronomy cameras, illuminating sensors with a diagonal up to 28mm. This accommodates a wide range of popular APS-C and smaller format CMOS and CCD cameras.

For 8" Celestron SCTs: Fastar and EdgeHD Compatibility

The HyperStar V4 for C8 is designed for any Celestron 8" SCT that is "Fastar-compatible," meaning it has a removable secondary mirror assembly. For older, non-Fastar tubes, a separate conversion kit is available from Starizona to make them HyperStar-ready.

This model is also fully compatible with Celestron's EdgeHD 8" optical tubes. The package includes a specific EdgeHD Adapter Ring that fits the same HyperStar unit to EdgeHD 8 optical tubes.

17.5mm Backfocus: The Standard M42 Adapter for Cooled Cameras

Achieving correct sensor spacing is critical at f/1.9. The HyperStar 8 ships with a Standard Camera Adapter that is precisely machined to place the sensor at the required 17.5mm backfocus distance. This adapter features standard M42 male T-threads, which covers most popular cooled astrocameras.

This pre-set distance eliminates the need for guesswork or complex spacer combinations. You simply thread your camera onto the adapter, and the critical backfocus is set. For cameras with different backfocus requirements or thread sizes (such as DSLRs or those requiring M54 threads), a range of alternative adapters are available separately.

Single 2" Filter Cell and Optional M42/M54 Filter Slider

The included Standard Camera Adapter accepts one standard 2" (M48) mounted filter. This is ideal for use with a light pollution, IR-cut, or multi-band nebula filter, allowing you to capture filtered data with a one-shot-color camera without additional accessories.

For imagers who need to swap between multiple filters, such as LRGB or narrowband, an optional Filter Slider Upgrade is available. This accessory replaces the standard adapter and provides a drawer system for quick filter changes. The optional slider includes both M42 and M54 male top plates, offering greater flexibility for connecting different cameras.

From f/10 to f/1.9 in Minutes: Reversible Installation

Converting your C8 for HyperStar imaging is a straightforward, reversible process. The secondary mirror is unthreaded from the corrector plate and stored securely in the included Secondary Mirror Holder. The HyperStar lens assembly then threads into its place. Reinstalling the secondary mirror returns the telescope to its native f/10 configuration.

Independent Camera Rotation and Precision Collimation

The HyperStar V4 design includes features for precise final adjustments. Independent camera rotation lets you turn the camera to frame your target without moving the lens.

The lens assembly also features adjustable collimation screws. These adjustments let you fine-tune the optical alignment of the lens.

Under 1 lb: Balancing the HyperStar on Your Mount

Weighing less than 1 lb, the HyperStar 8 lens and a typical astronomy camera add minimal weight to the front of the telescope. On a German equatorial mount, balance is easily achieved by sliding the optical tube forward in its saddle. A counterweight is not needed where the tube can slide in the saddle.

For fork-mounted (alt-azimuth) telescopes where the tube cannot slide, a separate HyperStar Counterweight (sold separately) fits into the 1.25" visual back at the rear of the telescope to balance the lens and camera on the front.

Achieving Critical Focus at an f/1.9 Focal Ratio

The extremely fast f/1.9 focal ratio creates a very narrow critical focus zone, meaning that precise focus is essential for sharp images. While challenging, achieving this is straightforward with modern tools. A Bahtinov mask is the most common method, providing a clear and unambiguous diffraction pattern that indicates perfect focus.

Automated focusing systems, combined with software that measures star size (FWHM), are also highly effective. The key is to make very small, deliberate adjustments with the telescope's focuser.

3.5" Body, Made in the USA: Build and Included Hardware

The HyperStar V4 lens assembly measures just 3.5" in length (without the camera adapter) and 3.0" in diameter. It has a black anodized finish and is designed and built in Tucson, Arizona.

The complete package includes everything needed to convert your telescope:

• HyperStar 8 (C8 v4) Lens: The core f/1.9 optical assembly.
• EdgeHD Adapter Ring: Ensures compatibility with Celestron EdgeHD 8 OTAs.
• Standard Camera Adapter: Provides M42 threads and sets the 17.5mm backfocus.
• Secondary Mirror Holder: A protective housing for your SCT's secondary mirror when not in use.