Secondary

Mirror

Secondary

Mirror

Retaining Ring

Corrector Plate

Secondary

Mirror Mount

Handle

Figure 8-2 - The Fastar Compatible Optical System

The above figure shows how the secondary mirror is removed when using the optional CCD camera at f/2 and the Fastar Lens Assembly.

Warning: The secondary mirror should never be removed unless installing the optional Fastar Lens Assembly. Adjustments to collimation can easily be made by turning the screws on the top of the secondary mirror mount without ever having to remove the secondary mirror (see Telescope Maintenance section of this manual).

The F/# stands for the ratio between the focal length and the diameter of the light gathering element. A NexStar 11 optical tube has a focal length of 110 inches and a diameter of 11 inches. This makes the system an f/10, (focal length divided by diameter). The NexStar 8 has a focal length of 80 inches and a diameter of 8 inches, also making it an f/10 optical system. When the secondary is removed and the CCD camera is placed at the Fastar position, the system becomes f/2, this is a unique feature to some Celestron telescopes (see figures below).

Figure 8-3

Fastar L ens Assem bl

CCD Camera

Figure 8-4

The key factors for good CCD imaging are; exposure time, field-of-view, image size, and pixel resolution. As the F/# goes down (or gets faster), the exposure times needed decreases, the field-of-view-increases, but the image scale of the object gets smaller. What is the difference between f/2 and f/10? F/2 has 1/5 the focal length of f/10. That makes the

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Celestron 93507 manual Fastar Compatible Optical System

93507 specifications

The Celestron 93507 is a powerful and versatile telescope designed for both amateur and seasoned astronomers. This model combines advanced technologies and practical features to deliver an enriching stargazing experience. One of the standout characteristics of the Celestron 93507 is its robust optical design. It features a 90mm aperture, allowing users to capture bright, detailed views of celestial objects, from the lunar surface to distant galaxies. The telescope employs a Maksutov-Cassegrain optical design, known for its compact form factor and high-quality images, free from chromatic aberration.

In terms of usability, the Celestron 93507 is designed with an easy setup in mind. It comes equipped with a solid mount that provides stability during observation. The mount also includes slow-motion controls, facilitating smooth panning across the night sky, allowing astronomers to track celestial objects effortlessly. This feature is particularly beneficial for viewing planets and other fast-moving astronomical phenomena.

Furthermore, the telescope comes with high-grade optics, including fully coated glass elements that enhance light transmission and ensure sharper images with higher contrast. It includes two eyepieces — a low-power 25mm and a high-power 10mm — that provide versatility in viewing options, whether you’re looking at wide expanses of the night sky or zooming in on close details of lunar craters.

Additionally, the Celestron 93507 is compatible with various Celestron accessories, including solar filters and advanced eyepieces, enabling users to expand their observational capabilities. The telescope's compact design makes it portable, perfect for amateur astronomers who enjoy taking their telescope for trips to dark-sky locations.

Another noteworthy feature of this telescope is its durability. Built to withstand the rigors of outdoor usage, the materials used in the Celestron 93507 are resistant to wear and tear, ensuring that users can enjoy stargazing for years.

Overall, the Celestron 93507 is a well-rounded instrument that combines advanced optical technology, user-friendly features, and portability, making it an excellent choice for anyone looking to explore the wonders of the universe. Whether you're interested in planetary observation, lunar details, or deep-sky wonders, this telescope offers the tools necessary to make your astronomical explorations rewarding.