User manual ORION TELESCOPES & BINOCULARS APEXMAKCASS

[. . . ] INSTRUCTION MANUAL Orion ® ApexTM Maksutov-Cassegrain Optical Tube AssembliesTM #9820 Apex 90mm #9823 Apex 102mm #9825 Apex 127mm Customer Support (800) 676-1343 E-mail: support@telescope. com Corporate Offices (831) 763-7000 Providing Exceptional Consumer Optical Products Since 1975 P. O. Box 1815, Santa Cruz, CA 95061 IN 161 Rev. A 0000 Eyepiece adapter 25mm Sirius Plossl eyepiece Finder scope bracket Correct-image finder scope Dovetail holder 45° correct-image diagonal Focus knob Mounting block Meniscus lens Figure 1: The Apex Maksutov-Cassegrain optical tube assembly parts diagram. The Apex 102mm is shown, but all models have similar components. Welcome to a new world of adventure! [. . . ] The finder scope is now focused, and should not need focusing again for your eyes. Calculating Magnification (Power) To calculate the magnification, or power, of a telescope with an eyepiece, simply divide the focal length of the telescope by the focal length of the eyepiece: Magnification = telescope focal length ÷ eyepiece focal length For example, the Apex 102mm, which has a focal length of 1300mm, used in combination with the supplied 25mm eyepiece, yields a power of: 1300 ÷ 25 = 52x. It is desirable to have a range of eyepieces of different focal lengths to allow viewing over a range of magnifications. It is not uncommon for an observer to own five or more eyepieces. Orion offers many different eyepieces of varying focal lengths, so check the catalog or website for a wide selection of additional eyepieces to choose from. Every telescope has a useful limit of power of about 2x per millimeter of aperture (i. e. Claims of higher power by some telescope manufacturers are a misleading advertising gimmick and should be dismissed. Keep in mind that at higher powers, an image will always be dimmer 4 Objective lens Alignment thumb screws to see what you're doing at the telescope, or to read star charts. Red light will not spoil your dark-adapted night vision as readily as white light will. To find celestial objects with your telescope, you first need to become reasonably familiar with the night sky. Unless you know how to recognize the constellation Orion, for instance, you won't have much luck locating the Orion Nebula. A simple planisphere, or star wheel, can be a valuable tool for learning the constellations and seeing which ones are visible in the sky on a given night. A good star chart or atlas, like the Orion DeepMap 600, can come in handy for helping locate interesting objects among the dizzying multitude of stars overhead. Except for the Moon and the brighter planets, it is pretty timeconsuming and frustrating to hunt for objects randomly, without knowing where to look. It is best to have specific targets in mind before you begin looking through the eyepiece. Focus lock ring Spring-loaded tensioner Eyepiece Figure 5. The 6x26 correct-image finder scope and bracket. and less sharp (this is a fundamental law of optics). The steadiness of the air (the "seeing") can also limit how much magnification an image can tolerate. Always start viewing with your lowest-power (longest focal length) eyepiece in the telescope. Try using a Moon filter to dim the Moon when it is too bright; it simply threads onto the bottom of the eyepiece. B. The Planets The planets don't stay put like stars do (planets don't have fixed R. A. coordinates), so you will have to refer to Sky Calendar at our website, www. telescope. com, or to charts published monthly in Astronomy, Sky & Telescope, or other astronomy references to locate them. Venus, Mars, Jupiter, and Saturn are the brightest objects in the sky after the Sun and the Moon. [. . . ] The famous "Double-Double" in the constellation Lyra and the gorgeous two-color double star Albireo in Cygnus are favorites. Defocusing the image of a star slightly can help bring out its color. D. Deep-Sky Objects Under dark skies, you can observe a number of brighter deep-sky objects with the Apex telescopes, including gaseous nebulas, open and globular star clusters, and the brighter galaxies. Most deep-sky objects are very faint, so it is important that you find an observing site well away from light pollution. [. . . ]