Related Manuals for Celestron AstroMaster LT
Summary of Contents for Celestron AstroMaster LT
- Page 1 ® Series Telescopes INSTRUCTION MANUAL LT 60AZ # 21073 • AstroMaster LT 70AZ # 21074 • AstroMaster ® ® LT 76AZ # 31036 • AstroMaster ®...
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Page 2: Table Of Contents
• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • AstroMaster LT Specifications... -
Page 3: Introduction
In addition, your AstroMaster LT telescope is ideal for terrestrial obser- vations which will open your eyes with superb high power viewing. - Page 4 Figure 1-1 AstroMaster LT 70AZ Refractor (AstroMaster LT 60AZ refractor similar) 1. Objective Lens 2. Telescope Optical Tube 3. Star Pointer Finderscope 4. Eyepiece 5. Diagonal 6. Focus Knob 7. Pan Handle 8. Accessory Tray 9. Tripod 10. Azimuth Lock 11.
- Page 5 Figure 1-2 AstroMaster LT 76 AZ Newtonian 1. Star Pointer Finderscope 2. Eyepiece 3. Telescope Optical Tube 4. Primary Mirror 5. Pan Handle 6. Azimuth Lock 7. Accessory Tray 8. Tripod 9. Alt-Az Mount 10. Dovetail Mounting Bracket 11. Focus Knob...
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Page 6: Assembly
Each AstroMaster LT comes in one box. The pieces in the box are – optical tube with attached sky pointer , Alt-Az mount with attached pan handle, 10 mm eyepiece – 1.25”, 20 mm eyepiece – 1.25”, mirror diagonal 1.25”... -
Page 7: Moving The Telescope Manually
MOVING THE TELESCOPE MANUALLY The AstroMaster LT Alt-Az mount is easy to move wherever you want to point it. The up and down (altitude) is controlled by the pan handle (Figure 2-10). The side-to-side (azimuth) is controlled by the azimuth lock (Figure 2-9). -
Page 8: Installing The Diagonal & Eyepieces (Refractor)
INSTALLING THE DIAGONAL & EYEPIECES ( REFRACTOR) The diagonal is a mirror assembly that diverts the light at a right angle to the light path of the refractor. This allows you to observe in a position that is more comfortable than if you looked straight through. Also, the diagonal can be rotated to any position which is most favorable for you. -
Page 9: Telescope Basics
TELESCOPE BASICS A telescope is an instrument that collects and focuses light. The nature of the optical design determines how the light is focused. Some telescopes, known as refractors, use lenses, .and other telescopes, known as reflectors (Newtonians), use mirrors. Developed in the early 1600s, the refractor is the oldest telescope design. -
Page 10: Image Orientation
IMAGE ORIENTATION The image orientation changes depending on how the eyepiece is inserted into the telescope. When using a star diagonal with refractors, the image is right-side-up, but reversed from left-to-right (i.e., mirror im- age). If inserting the eyepiece directly into the focuser of a refractor (i.e., without the diagonal), the image is upside-down and reversed from left-to-right (i.e., inverted). -
Page 11: Calculating Magnification
144 power. Although this is the maximum useful magnification, most observing is done in the range of 20 to 35 power for every inch of aperture which is 48 to 84 times for the AstroMaster LT 60AZ telescope. You can... -
Page 12: Determining Field Of View
field of view using the same 20mm eyepiece that is supplied standard with the AstroMaster LT 60AZ telescope. The 20mm eyepiece has an apparent field of view of 50°. Divide the 50° by the magnification, which is 30 power. This yields an actual field of 1.7°. -
Page 13: Astronomy Basics
ASTRONOMY BASICS Up to this point, this manual covered the assembly and basic operation of your telescope. However, to un- derstand your telescope more thoroughly, you need to know a little about the night sky. This section deals with observational astronomy in general and includes information on the night sky and polar alignment. For telescopes with equatorial mounts, the users have setting circles and polar alignment methods to help them find objects in the sky. -
Page 14: Motion Of The Stars
MOTION OF THE STARS The daily motion of the Sun across the sky is familiar to even the most casual observer. This daily trek is not the Sun moving as early astrono- mers thought, but the result of the Earth’s rota- tion. -
Page 15: Celestial Observing
See the “Seeing Conditions” section later in this section. • To increase contrast and bring out detail on the planetary surface, try using Celestron eyepiece filters. OBSERVING THE SUN Although overlooked by many amateur astronomers, solar observation is both rewarding and fun. How- ever, because the Sun is so bright, special precautions must be taken when observing our star so as not to damage your eyes or your telescope. -
Page 16: Observing Deep Sky Objects
“guide” you to an object. For successful star hopping, it is helpful to know the field of view of you tele- scope. If you’re using the standard 20mm eyepiece with the AstroMaster LT telescope, your field of view is approximately 1º. - Page 17 Star hopping to the Andromeda Galaxy (M31) is a snap, since all the stars needed to do so are visible to the naked eye. Star hopping will take some getting used to and objects that don’t have stars near them that are visible to the naked eye are challenging.
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Page 18: Seeing Conditions
SEEING CONDITIONS Viewing conditions affect what you can see through your telescope during an observing session. Condi- tions include transparency, sky illumination, and seeing. Understanding viewing conditions and the effect they have on observing will help you get the most out of your telescope. Transparency Transparency is the clarity of the atmosphere which is affected by clouds, moisture, and other airborne particles. -
Page 19: Astrophotography
ASTROPHOTOGRAPHY The AstroMaster LT series of telescopes was designed for visual observing. After looking at the night sky for a while you may want to try your hand at photography of it. There are several forms of photography possible with your telescope for celestial as well as terrestrial pursuits. Below is just a very brief discussion of some of the methods of photography available and suggest you search out various books for detailed information on the subject matter. -
Page 20: Telescope Maintenance
Internal adjustments and cleaning should be done only by the Celestron repair department. If your tele- scope is in need of internal cleaning, please call the factory for a return authorization number and price quote. - Page 21 The following describes the procedure for daytime collimation of your telescope using the optional Newto- nian Collimation Tool (#94183) offered by Celestron. To collimate the telescope without the Collimation Tool, read the following section on night time star collimation. For very precise collimation, the optional Collima- tion Eyepiece 1 ¼”...
- Page 22 Night Time Star Collimating After successfully completing daytime collimation, night time star collimation can be done by closely adjusting the primary mirror while the telescope tube is on its mount and pointing at a bright star. The telescope should be set up at night and a star’s image should be studied at medium to high power (30-60 power per inch of aperture).
- Page 23 Figure 7-2 Even though the star pattern appears the same on both sides of focus, they are asymmetric. The dark obstruction is skewed off to the left side of the diffraction pattern indicating poor collimation. When satisfied with the collimation, tighten the small locking screws. Take note of the direction the light appears to flare.
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Page 24: Astromaster Lt Specifications
ASTROMASTER LT SPECIFICATIONS 21073 21074 31036 AM 60 AZ AM 70AZ AM 76 AZ Optical Design Refractor Refractor Newtonian Aperture 60mm (2.4”) 70mm (2.7”) 76mm (3.0”) Focal Length 700mm 700mm 700mm Focal Ratio f/12 f/10 Secondary Mirror Obstruction -- Dia. - Area... - Page 25 Torrance, CA 90503 U.S.A. Tel. (310) 328-9560 Fax. (310) 212-5835 Website www.celestron.com Copyright 2012 Celestron All rights reserved. (Products or instructions may change without notice or obligation.) Designed and intended for those 13 years of age and older WARNING: This product contains a chemical(s) known to the State of California to cause cancer, birth defects or other reproductive harm.