ENGLISH OOmmnnii XXLLTT SSeerriieess TTeelleessccooppeess INSTRUCTION MANUAL ● Omni XLT 102 ● Omni XLT 102ED ● Omni XLT 120 ● Omni XLT127 ● Omni XLT 150 ● Omni XLT 150R Table of Contents INTRODUCTION .......................................................................................................................................................... 4 Warning...................................................................................................................................................... 4 ASSEMBLY .................................................................................................................................................................... 8 Setting up the Tripod.................................................................................................................................. 8 Attaching the Equatorial Mount ................................................................................................................. 9 Attaching the Center Leg Brace ............................................................................................................... 10 Installing the Counterweight Bar.............................................................................................................. 10 Installing the Counterweights................................................................................................................... 11 Attaching the Slow Motion Control Knobs (Cables)................................................................................11 Attaching the Telescope Tube to the Mount............................................................................................. 12 Installing the Finderscope......................................................................................................................... 13 Installing the Visual Back......................................................................................................................... 13 Installing the Star Diagonal ...................................................................................................................... 14 Installing the Eyepieces............................................................................................................................ 14 Moving the Telescope Manually .............................................................................................................. 15 Balancing the Mount in R.A..................................................................................................................... 15 Balancing the Mount in DEC ................................................................................................................... 16 Adjusting the Mount................................................................................................................................. 16 Adjusting the Mount in Altitude............................................................................................................... 17 Adjusting the Mount in Azimuth.............................................................................................................. 17 TELESCOPE BASICS ................................................................................................................................................. 18 Image Orientation..................................................................................................................................... 20 Focusing ................................................................................................................................................... 20 Aligning the Finderscope ......................................................................................................................... 21 Calculating Magnification ........................................................................................................................ 21 Determining Field of View....................................................................................................................... 22 General Observing Hints .......................................................................................................................... 22 ASTRONOMY BASICS............................................................................................................................................... 23 The Celestial Coordinate System ............................................................................................................. 23 Motion of the Stars ................................................................................................................................... 24 Latitude Scale........................................................................................................................................... 25 Pointing at Polaris .................................................................................................................................... 25 Finding the North Celestial Pole .............................................................................................................. 26 Polar Alignment in the Southern Hemisphere .......................................................................................... 27 Pointing at Sigma Octantis ....................................................................................................................... 28 Finding the South Celestial Pole (SCP).................................................................................................... 28 Declination Drift Method of Polar Alignment.......................................................................................... 29 Aligning the R.A. Setting Circle .............................................................................................................. 30 Using the R.A. Vernier Scale ................................................................................................................... 31 CELESTIAL OBSERVING......................................................................................................................................... 32 Observing the Moon................................................................................................................................. 32 Lunar Observing Hints ............................................................................................................................. 32 Observing the Planets............................................................................................................................... 32 Observing the Sun .................................................................................................................................... 33 Solar Observing Hints .............................................................................................................................. 33 Observing Deep Sky Objects.................................................................................................................... 33 Seeing Conditions..................................................................................................................................... 33 2 Transparency ............................................................................................................................................ 33 Sky Illumination....................................................................................................................................... 33 Seeing....................................................................................................................................................... 34 Using the Lens Cap Aperture Stop with Refractor Telescopes ................................................................ 34 ASTROPHOTOGRAPHY ........................................................................................................................................... 35 Piggyback Photography............................................................................................................................ 35 Short Exposure Prime Focus Photography for Refractors & Newtonians................................................ 36 Short Exposure Prime Focus Photography for Schmidt-Cassegrains....................................................... 36 Eyepiece Projection for a Schmidt-Cassegrain......................................................................................... 37 Long Exposure Prime Focus Photography ............................................................................................... 38 Planetary and Lunar Photography with Special Imagers.......................................................................... 39 CCD Imaging for Deep Sky Objects ........................................................................................................ 40 Terrestrial Photography............................................................................................................................ 40 Metering ................................................................................................................................................... 40 Reducing Vibration .................................................................................................................................. 40 TELESCOPE MAINTENANCE ................................................................................................................................. 41 Care and Cleaning