Schmidt-Cassegrain Optical Tube Assembly Instruction Manual C8 ● C9.
A telescope is an instrument that collects and focuses light. The nature of the optical design determines how the light is focused. Some telescopes, known as refractors, use lenses. Other telescopes, known as reflectors, use mirrors. The Schmidt-Cassegrain optical system (or Schmidt-Cass for short) uses a combination of mirrors and lenses and is referred to as a compound or catadioptric telescope.
Once this is done, you are ready to attach other accessories, such as eyepieces, diagonal prisms, etc. If you want to remove the visual back, rotate the slip ring counterclockwise until it is free of the rear cell. Installing the Star Diagonal The star diagonal is a prism that diverts the light at a right angle to the light path of the telescope. This allows you to observe in positions that are physically more comfortable than if you looked straight through. To attach the star diagonal onto the 8", 9.
3. Tighten the set screw on the star diagonal to hold the eyepiece in place. To remove the eyepiece, loosen the set screw on the star diagonal and slide the eyepiece out. You can replace it with another eyepiece (purchased separately). Eyepieces are commonly referred to by focal length and barrel diameter. The focal length of each eyepiece is printed on the eyepiece barrel. The longer the focal length (i.e., the larger the number) the lower the eyepiece power and the shorter the focal length (i.e.
6. Slightly tighten the three nylon tipped thumbscrews on the front ring of the bracket to hold the finder in place. 7. Once on, push the finder back until the O-ring is snug inside the back ring of the finder bracket. 8. Hand tighten the three nylon tipped thumbscrews until snug. Aligning the Finderscope Accurate alignment of the finder makes it easy to find objects with the telescope, especially celestial objects.
Image Orientation The image orientation changes depending on how the eyepiece is inserted into the telescope. When using the star diagonal, the image is right-side-up, but reversed from left-to-right (i.e., mirror image). If inserting the eyepiece directly into the visual back (i.e., without the star diagonal), the image is upside-down and reversed from left-to-right (i.e., inverted). This is normal for the Schmidt-Cassegrain design.
Fastar Lens Assembly Option – Using your CGE telescope at f/2 with optional Fastar Lens Assembly Some C8 and C14 optical tubes are equipped with a removable secondary mirror (see Table 1-1) that allows you to convert your f/10 telescope into an f/2 imaging system capable of exposure times 25 times shorter than those needed with a f/10 system! With the optional Fastar lens assembly you can easily convert your Fastar compatible telescope to f/2 prime focus use in a matter of seconds.
Fastar L ens Assem bl CCD Camera Figure 1-8 Figure 1-9 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.
Internal adjustments and cleaning should be done only by the Celestron repair department. If your telescope is in need of internal cleaning, please call the factory for a return authorization number and price quote. Collimation The optical performance of your telescope is directly related to its collimation, that is the alignment of its optical system. Your telescope was collimated at the factory after it was completely assembled.
3. Locate the collimation screw closest to where your finger is positioned. This will be the collimation screw you will need to adjust first. (If your finger is positioned exactly between two of the collimation screws, then you will need to adjust the screw opposite where your finger is located). 4. Use the hand control buttons to move the de-focused star image to the edge of the field of view, in the same direction that the central obstruction of the star image is skewed. 5.
CELESTRON TWO YEAR WARRANTY A. Celestron warrants this telescope to be free from defects in materials and workmanship for two years. Celestron will repair or replace such product or part thereof which, upon inspection by Celestron, is found to be defective in materials or workmanship. As a condition to the obligation of Celestron to repair or replace such product, the product must be returned to Celestron together with proof-of-purchase satisfactory to Celestron. B.
Celestron 2835 Columbia Street Torrance, CA 90503 Tel. (310) 328-9560 Fax. (310) 212-5835 Web site at http//www.celestron.com Copyright 2005 Celestron All rights reserved. (Products or instructions may change without notice or obligation.) Item # 91024-INST $10.
