User manual ORION TELESCOPES & BINOCULARS STARMAX 90 EQ

[. . . ] INSTRUCTION MANUAL Orion StarMaxTM 90 EQ ® #9821 Equatorial Maksutov-Cassegrain Telescope Customer Support (800) 676-1343 E-mail: support@telescope. com Corporate Offices (831) 763-7000 Providing Exceptional Consumer Optical Products Since 1975 P. O. B 03/02 Finder scope bracket Finder scope Mounting block Eyepiece Counterweight shaft Right Ascension slow-motion control Counterweight Counterweight lock knob Star diagonal Declination slow motion control Tripod leg Accessory tray Accessory tray bracket Leg lock knob Figure 1. Your new StarMax 90mm EQ is designed for high-resolution observing of astronomical objects, and can also be used for terrestrial exploration. With its precision optics and equatorial mount, you'll be able to locate and enjoy hundreds of fascinating celestial objects, including the planets, Moon, and a variety of deep-sky galaxies, nebulas, and star clusters. [. . . ] axis until it points in the south direction. 8 What if you need to aim the telescope directly north, but at an object that is nearer to the horizon than Polaris?You can't do it with the counterweight down as pictured in Figure 1. To point the telescope to the east or west, or in other directions, you rotate the telescope on its R. A. Depending on the altitude of the object you want to observe, the counterweight shaft will be oriented somewhere between vertical and horizontal. Figure 6 illustrates how the telescope will look pointed at the four cardinal directions - north, south, east, and west The key things to remember when pointing the telescope is that a) you only move it in R. A. and Dec. , not in azimuth or latitude (altitude), and b) the counterweight and shaft will not always appear as it does in Figure 1. Using Your Telescope-- Astronomical Observing Choosing an Observing Site When selecting a location for observing, get as far away as possible from direct artificial light such as street lights, porch lights, and automobile headlights. The glare from these lights will greatly impair your dark-adapted night vision. 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 stars you can see with the unaided eye (6th magnitude or fainter is desirable). [. . . ] Now, connect the optical tube to a photo tripod by threading the tripod's 1/4"-20 shaft into the hole in the tube's mounting block. The included mirror star diagonal, while preferred for astronomical observing because of its viewing angle and better resolution, is not optimal for land viewing because it inverts images from left-to-right. We recommend purchasing an optional 45° correct-image diagonal for terrestrial observing; it provides a more comfortable viewing angle for land viewing and an image that is oriented the same as the naked eye. For terrestrial viewing, it's best to stick with low power eyepieces that yield a magnification under 100x. [. . . ]