User manual ORION TELESCOPES & BINOCULARS SPACEPROBE 3EQ

[. . . ] INSTRUCTION MANUAL Orion SpaceProbe 3 EQ ® #9847 and #9842 Customer Support (800) 676-1343 E-mail: support@telescope. com Corporate Offices (831) 763-7000 Providing Exceptional Consumer Optical Products Since 1975 P. O. A 0801 Finder scope Finder scope bracket Eyepiece Focuser Optical tube assembly Declination slow-motion control cable Declination setting circle Right Ascension setting circle Declination lock knob Right Ascension slow motion cable Counterweight shaft Counterweight Counterweight lock knob Right Ascension lock knob Accessory tray Latitude adjustment T-Bolt Tripod leg Accessory tray bracket attachment point Accessory tray bracket Leg lock knob Figure 1. 2 Welcome to the exciting world of amateur astronomy!Your SpaceProbe 3 EQ is a high-quality optical instrument designed for nighttime stargazing. With its precision optics and equatorial mount, you'll be able to locate and enjoy fascinating denizens of the night sky, including the planets, Moon, and a variety of deep-sky objects. [. . . ] Set up on a grass or dirt surface, not asphalt, because asphalt radiates more heat. Heat disturbs the surrounding air and degrades the images seen through the telescope. Avoid viewing over rooftops and chimneys, as they often have warm air currents rising from them. Similarly, avoid observing from indoors through an open (or closed) window, because the temperature difference between the indoor and outdoor air will cause image blurring and distortion. If at all possible, escape the light-polluted city sky and head for darker country skies. You'll be amazed at how many more stars and deep-sky objects are visible in a dark sky!"Seeing" and Transparency Atmospheric conditions vary significantly from night to night. "Seeing" refers to the steadiness of the Earth's atmosphere at a given time. In conditions of poor seeing, atmospheric turbulence causes objects viewed through the telescope to "boil". If, when you look up at the sky with just your eyes, the stars are twinkling noticeably, the seeing is bad and you will be limited to viewing with low powers (bad seeing affects images at high powers more severely). In conditions of good seeing, star twinkling is minimal and images appear steady in the eyepiece. Also, seeing generally gets better after midnight, when much of the heat absorbed by the Earth during the day has radiated off into space. Especially important for observing faint objects is good "transparency" ­ air free of moisture, smoke, and dust. Transparency is judged by the magnitude of the faintest 9 1. 9 or more eyepieces to access a wide range of magnifications. This allows the observer to choose the best eyepiece to use depending on the object being viewed. To calculate the magnification, or power, of a telescope and eyepiece combination, simply divide the focal length of the telescope by the focal length of the eyepiece: 4. 9 2. 4 1. 9 1. 7 3. 4 2. 5 2. 4 Magnification = (focal length of telescope) ÷ (focal length of eyepiece) For example, the SpaceProbe 3 EQ, which has a focal length of 700mm, used in combination with the 25mm eyepiece, yields a power of: 700mm ÷ 25mm = 28x Every telescope has a useful limit of power of about 2x per mm of aperture (about 152x for the SpaceProbe 3 EQ). 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 and less sharp (this is a fundamental law of optics). The steadiness of the air (the "seeing") will also limit how much magnification an image can tolerate. Whatever you choose to view, always start by inserting your lowest-power (longest focal length) eyepiece to locate and center the object. Low magnification yields a wide field of view, which shows a larger area of sky in the eyepiece. If you try to find and center objects with high power (narrow field of view), it's like trying to find a needle in a haystack! [. . . ] Star-Testing theTelescope When it is dark, point the telescope at a bright star and accurately center it in the eyepiece's field of view. If the telescope is correctly collimated, the expanding disk should be a perfect circle (Figure 12). The dark shadow cast by the secondary mirror should appear in the very center of the out-of-focus circle, like the hole in a donut. If the "hole" appears off-center, the telescope is out of collimation. [. . . ]