Introduction to Fastar and HyperStar Systems
In the realm of astrophotography, the Celestron HyperStar system is revolutionising the use of Schmidt-Cassegrain Telescopes (SCTs). This innovative optical modification alters the traditional f/10 optical system of SCTs, transforming them into faster, wide-field imaging instruments.
The HyperStar system replaces the secondary mirror with a camera or a camera lens mounted at the front of the telescope. This conversion results in a much faster focal ratio, typically around f/2, significantly improving the performance of SCTs for astrophotography.
A longer focal ratio spreads light over a larger area of the digital image sensor, requiring longer exposure times. By contrast, the faster focal ratio of the HyperStar system allows for much shorter exposure times and brighter images. This is because the telescope’s aperture speed increases, gathering more light per unit time on the camera sensor compared to the usual f/10 system.
This transformation broadens the field of view and enables the capture of wide-field images with greater sensitivity and less time needed per frame. In essence, the HyperStar system turns the SCT from a long focal length, slower system into a fast, wide-field imaging instrument.
The benefits of the HyperStar system are manifold. It reduces tracking errors’ impact since exposures are shorter, facilitates easier focus, and enables the imaging of fainter objects or larger sky areas with a given camera and mount setup. This system is particularly beneficial for capturing large nebulae, star clusters, and wide deep-sky targets that would otherwise require very long exposures at f/10.
Amateur astrophotographers can easily connect cameras to Celestron SCTs, and the HyperStar system is compatible with a wide range of these telescopes. The secondary mirror mount created by Celestron allows for easy removal and replacement of the mirror, and when it is removed, the socket accepts an adapter for a camera.
Celestron introduced the Fastar system in the 1990's, which changes the primary mirror’s curvature to f/2 and the secondary to f/5, resulting in an f/10 focal ratio. The Fastar lens, which includes optical correcting lenses to perform some of the same corrective functions as the secondary mirror and further flatten the field, was discontinued by Celestron in 2005. However, Celestron granted permission to Starizona to continue the technology, and today, Starizona's version, dubbed HyperStar, is available for a wide range of Celestron SCTs from the C6 on up.
SCTs, with their standard focal length of 2,032 mm, have a long focal length inherent to their design which results in a narrow field of view and longer exposures. By switching to HyperStar, the focal ratio shortens dramatically, making the telescope more versatile and efficient for imaging faint and extended celestial objects.
Telescopes with shorter focal ratios capture the same level of signal in one-quarter the time compared to telescopes with longer focal ratios. This means that the HyperStar system can capture the same amount of signal in 1 minute that the full f/10 focal ratio would capture in 25 minutes.
In summary, the Celestron HyperStar system converts an SCT’s f/10 focal ratio into a fast f/2 system, improving astrophotography by substantially shortening exposure times and increasing the field of view compared to traditional f/10 SCT use. This makes the telescope more versatile and efficient for imaging faint and extended celestial objects.
- With the HyperStar system, Celestron Schmidt-Cassegrain Telescopes (SCTs) become advanced instruments for astrophotography, as they switch from a slow, long-field view to a fast, wide-field view, enabling the capture of bright images with shorter exposure times.
- The advancement in technology with the HyperStar system has made it possible for amateur astrophotographers to capture detailed images of larger deep-sky targets like nebulae and star clusters, previously requiring considerable time with traditional f/10 SCTs.
- By converting an SCT's focal ratio from f/10 to a faster f/2, the HyperStar system not only enhances the performance in astrophotography but also speeds up the imaging process, collecting the same amount of signal four times faster than telescopes with longer focal ratios.
