User manual ORION TELESCOPES & BINOCULARS 09005

[. . . ] INSTRUCTION MANUAL Orion AstroView 120ST EQ ® TM #9005 Equatorial Refracting 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. Box 1815, Santa Cruz, CA 95061 IN 155 Rev. A 0101 Tube rings Objective lens cell Dew cap/lens shade Declination lock lever Large counterweight Small counterweight Finder scope Finder bracket Focus knob Eyepiece Star diagonal Right Ascension slow-motion control Declination slow-motion control Right Ascension lock lever Polar axis finder scope Latitude adjustment T-bolts Counterweight lock knobs Counterweight shaft "Toe saver" Tripod leg Accessory tray attachment point Accessory tray bracket Accessory tray Leg lock knob Figure 1. The AstroView 120ST EQ Refractor 2 Congratulations on your purchase of a quality Orion telescope! [. . . ] The declination setting circle was calibrated at the factory, and should read 90° when the telescope optical tube is pointing exactly along the R. A. Calibrating the Right Ascension Setting Circle 1. Identify a bright star near the celestial equator and look up its coordinates in a star atlas. 2. lock levers on the equatorial mount, so the telescope optical tube can move freely. 3 Point the telescope at the bright star whose coordinates you know. Center the star in the telescope's eyepiece. Loosen the large thumbscrew just above the R. A. setting circle so the pointer indicates the R. A. coordinate listed for the bright star in the star atlas. Do not retighten the thumbscrew when using the R. A. setting circles for finding objects; the thumbscrew is only needed for polar alignment using the polar axis finder scope. Finding Objects With the Setting Circles Now that both setting circles are calibrated, look up in a star atlas the coordinates of an object you wish to view. lock lever and rotate the telescope until the Dec. value from the star atlas matches the reading on the Dec. If the telescope is being aimed toward the south and the Dec. setting circle pointer passes the 0° indicator, the value on the Dec. setting circle becomes a negative number. lock lever and rotate the telescope until the R. A. value from the star atlas matches the reading on the R. A. Most setting circles are not accurate enough to put an object dead-center in your finder scope's field of view, but they'll get you close, assuming the equatorial mount is accurately polaraligned. setting circle should be recalibrated every time you wish to locate a new object. Do so by calibrating the setting circle for the centered object before moving on to the next one. [. . . ] If you wish, you may apply some auto touch-up paint to the scratch. Smudges on the tube can be wiped off with a soft cloth and a household cleaner such as Windex or Formula 409. Cleaning the Optics A small amount of dust or a few specks on the glass objective (main) lens will not affect the performance of the telescope. If dust builds up, however, simply blow it off with a blower bulb, or lightly brush it off with a soft camel hair brush. [. . . ]