Celestron 11055 manual

CELESTRON CI-700 / CM-1 100 / CM-1400 INSTRUCTION MANUAL Models #91525 / #1 1055 / #1 1065[...]

ii • Table of Contents The Celestron CM -1 1 00/1400 Copyright © 1998 Celestron International 2835 Columbia Street Torrance, CA 90503 (310) 328-9560 No part of this manual may be reproduced in any form or by any means, electronic or mechanical, including photocopy- ing, recording, or by any information storage and retrieval system, without writt[...]

Table of Contents • i i i ▲ ▲ ▲ ▲ ▲ INTRODUCTION ................................................................................................................ .................. 1 How to Use this Manual ......................................................................................................... ............ 2 A Word of C[...]

iv • Table of Contents ▲ ▲ ▲ ▲ ▲ USING THE DRIVE .............................................................................................................. ............... 3 7 Powering Up the Drive .......................................................................................................... ............ 3 7 Guide Speed [...]

Introduction • 1 INTRODU CTION Welcome to the Celestron world of amateur astronomy! For more than a quarter of a century, Celestron has provided amateur astronomers with the tools needed to explore the universe. The Celestron CM-1100 and CM-1400 continues in this proud tradition combining large aperture optics with ease of use and portability. Wi[...]

2 • Introduction This manual is designed to instruct you in the proper use of your Celestron CM-1100 telescope. The instructions are for assembly, initial use, long term operation, and maintenance. There are seven major sections to the manual. The first section covers the proper procedure for setting up your Celestron CM- 1100 telescope. This inc[...]

Introduction • 3 DREN ARE PRESENT OR ADULTS WHO MAY NOT BE FAMILIAR WITH THE CORRECT OPERATING PROCEDURES OF YOUR TELESCOPE. NEVER POINT YOUR TELESCOPE AT THE SUN UNLESS YOU HAVE THE PROPER SOLAR FILTER. WHEN USING YOUR TELESCOPE WITH THE CORRECT SOLAR FILTER, ALWAYS COVER THE FINDER. ALTHOUGH SMALL IN APERTURE, THIS INSTRUMENT HAS ENOUGH LIGHT G[...]

4 • Assembling Your CM-1100 ASSEMBLING YOUR CM-1 100 This section covers the assembly instructions for your Celestron CM-1100 telescope. The Celestron CM-1100 should be set up indoors the first time so that it is easy to identify the various parts and familiarize yourself with the correct assembly procedure before attempting it outdoors. The Cele[...]

Assembling Your CM-1100 • 5 Figure 2-1 1. Optical Tube 2. Finderscope 3. Star Diagonal 4. Eyepiece 5. Polar Axis Finderscope 6. Drive Control Electronics 7. Hand Control 8. Tripod 9. Center Leg Brace 10. Counterweight 11. Counterweight Bar 12. R.A. Clutch Knob 13. DEC Clutch Knob 14. Mounting Platform Clamp Knob 15. Dovetail Slidebar 16. Objectiv[...]

6 • Assembling Your CM-1100 Setting Up the Tripod The tripod legs attach to a central column which together form the tripod to which the equatorial mount attaches. The tripod comes with two leg support brackets; a collapsible one that is already attached to the lower legs and a removable one that must be attached. To set up the tripod: 1. Stand t[...]

Assembling Your CM-1100 • 7 Before the equatorial mount head can be installed, the central column with the electronics module must be attached to the tripod. To attach the central column: 1 Position the central column so that the electronics module is right side up (see Figure 2-4). 2 Place the lower end of the central column over the tripod head[...]

8 • Assembling Your CM-1100 After the tripod is set up, you are ready to attach the equatorial mount. The equatorial mount is the platform to which the telescope attaches and allows you to move the telescope in right acsension and declination. The mount is also adjustable so you can orient the axis of rotation so that it is parallel with the Eart[...]

Assembling Your CM-1100 • 9 To properly balance the telescope, the mount comes with a counterweight bar and one counterweight (the CM-1400 comes with two counterweights). The counterweight bar is located in the same box as the Equatorial Mount Head — in a cutout along the bottom of the shipping box. To install the counterweight bar: 1. Locate t[...]

10 • Assembling Your CM-1100 The telescope attaches to the mount via a dovetail slide bar which is mounted along the bottom of the telescope. Before you attach the optical tube, make sure that the declination and right ascension clutch knobs are tight. This will ensure that the mount does not move suddenly while attaching the telescope. To mount [...]

Assembling Your CM-1100 • 11 The visual back is the accessory that allows you to attach all visual accesso- ries to the telescope. To attach the visual back: 1. Remove the plastic cover on the rear cell. 2. Place the knurled slip ring on the visual back over the threads on the rear cell. 3. Hold the visual back with the set screw in a convenient [...]

12 • Assembling Your CM-1100 The eyepiece, or ocular, is an optical element that magnifies the image focused by the telescope. The ocular(s) fit into either the visual back directly, the star diagonal, or the Erect Image Diagonal (purchased separately). To install an ocular: 1 . Loosen the set screw on the star diagonal until the tip no longer ex[...]

Assembling Your CM-1100 • 13 The CM-1100 telescope come with a 9x50 finderscope used to help you locate and center objects in the main field of your telescope. To accomplish this, the finder has a built-in cross-hair reticle that shows the optical center of the finderscope. Start by removing the finder and hardware from the plastic wrapper. Inclu[...]

14 • Assembling Your CM-1100 To aid in polar aligning the mount, your telescope comes standard with a Polar Housing Finder. It installs directly on top of the polar housing of the mount. To install the Polar Finder: 1 . Locate the Polar Finder assembly. The Polar Finder assembly consists of the polar finder, mounting bracket and knurled mounting [...]

Assembling Your CM-1100 • 15 Once set up, you need to point your telescope at various portions of the sky to observe different objects. To make rough adjustments, loosen the R.A. and DEC clutch knobs slightly and move the telescope in the desired direction. Both the R.A. and DEC axis have two knobs to clutch down each axis of the telescope. To lo[...]

16 • Assembling Your CM-1100 In order for the clock drive to track accurately, the telescope’s axis of rotation must be parallel to the Earth’s axis of rotation, a process known as polar alignment. Polar alignment is achieved NOT NOT NOT NOT NOT by moving the telescope in R.A. or DEC, but by adjusting the mount vertically, which is called alt[...]

Assembling Your CM-1100 • 17 To eliminate undue stress on the mount, the telescope should be properly balanced around the polar axis. Proper balancing is crucial for accurate tracking. To balance the mount: 1 . Verify that the telescope securing knobs on the telescope mounting platform are tight. 2 . Loosen the R.A. clutch knobs and position the [...]

18 • Assembling Your CM-1100 Although the telescope does not track in declination, the telescope should also be balanced in this axis to prevent any sudden motions when the DEC clutch knob is loose. To balance the telescope in DEC: 1 . Loosen the R.A. clutch knobs and rotate the telescope so that it is on one side of the mount (i.e., as described[...]

Assembling Your CM-1100 • 19 Because of the Celestron CM-1100's size and weight, you should ALWAYS ALWAYS ALWAYS ALWAYS ALWAYS remove the telescope from the mount when moving the telescope. To do so: 1 . Take the telescope off of the mount and return it to its shipping box. 2 . Remove the counterweight from the counterweight bar. 3 . Remove [...]

20 • Assembling Your CM-1100 Below is pertinent technical information on your Celestron CM-1100 telescope that you may find useful. OPTICAL TUBE: OPTICAL TUBE: OPTICAL TUBE: OPTICAL TUBE: OPTICAL TUBE: CM-1100 CM-1100 CM-1100 CM-1100 CM-1100 CM-1400 CM-1400 CM-1400 CM-1400 CM-1400 Optical System: Schmidt-Cassegrain Schmidt-Cassegrain Aperture: 11[...]

Assembling Your CM-1100 • 21 TRIPOD: TRIPOD: TRIPOD: TRIPOD: TRIPOD: • All machined aluminum • Semi-pier Tripod Design • Fixed hieght Tripod with dual leg support • Tripod legs are 48.5" long • Tripod hieght is 49" high (fully extended with column attached) • Tripod weight approximately 20 pounds • Weight of equatorial hea[...]

22 • Telescope Basics TELESCOPE BASICS Once your telescope is fully assembled, you are ready for your first look. This section deals with some of the basics of telescope operation. The image orientation changes depending on how the eyepiece is inserted into the telescope. When using the star diagonal, the image is right-side-up, but reversed from[...]

Telescope Basics • 2 3 The Celestron CM-1100 focusing mechanism controls the primary mirror which is mounted on a ring which slides back and forth on the primary baffle tube. The focusing knob, which moves the primary mirror, is on the rear cell of the telescope just right of the star diagonal and eyepiece. Turn the focusing knob until the image [...]

24 • Telescope Basics Your Celestron CM-1100 can be used for both terrestrial and astronomical photography. Your Celestron CM-1100 has a fixed aperture and, as a result, a fixed f/ratio. To properly expose your subjects photographically you need to set your shutter speed accordingly. Most 35mm single lens reflex (SLR) cameras offer through-the-le[...]

Telescope Basics • 2 5 With the telescope fully assembled and all the accessories attached, you are ready for your first look. Your first look should be done in the daytime when it is easier to locate the locking clutches. This will help to familiarize you with your telescope, thus making it easier to use at night. Daytime Observing As mentioned [...]

26 • Telescope Basics Nighttime Observing Looking at objects in the sky is quite different than looking at objects on Earth. For one, many objects seen in the daytime are easy to see with the naked eye and can be located in the telescope by using landmarks. In the night sky many objects are not visible to the naked eye. To make things easier, you[...]

Telescope Basics • 2 7 You can change the power of your Celestron CM-1100 telescope just by changing the eyepiece (ocular). To determine the magnification of your Celestron CM-1100, simply divide the focal length of the telescope by the focal length of the eyepiece used. In equation format, the formula looks like this: Focal Length of Telescope ([...]

28 • Astronomy Basics ASTRONOMY BASICS The following section deals with observational astronomy in general. It in- cludes information on the night sky, polar alignment, and using your telescope for astronomical observing. In order to help find objects in the sky, astronomers use a celestial coordinate system which is similar to our geographical c[...]

Astronomy Basics • 29 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 astronomers thought, but the result of the Earth ’ s rotation. The Earth ’ s rotation also causes the stars to do the same, scribing out a large circle as the Earth completes one rotatio[...]

30 • Astronomy Basics In order for the telescope to track the stars, you must meet two criteria. First, you need a drive motor that moves at the same rate as the stars. The Celestron CM-1100 comes standard with a built-in drive motor designed specifically for this purpose. The second thing you need is to set the telescope ’ s axis of rotation s[...]

Astronomy Basics • 31 In each hemisphere, there is a point in the sky around which all the other stars appear to rotate. These points are called the celestial poles and are named for the hemisphere in which they reside. For example, in the northern hemisphere all stars move around the north celestial pole. When the telescope ’ s polar axis is p[...]

32 • Astronomy Basics Latitude Scales The easiest way to polar align a telescope is with a latitude scale. Unlike other methods that require you to find the celestial pole by identifying certain stars near it, this method works off of a known constant to determine how high the polar axis should be pointed. The Celestron CM-1100 mount can be adjus[...]

Astronomy Basics • 33 Pointing at Polaris This method utilizes Polaris as a guidepost to the celestial pole. Since Polaris is less than a degree from the celestial pole, you can simply point the polar axis of your telescope at Polaris. Although this is by no means perfect alignment, it does get you within one degree. Unlike the previous method, t[...]

34 • Astronomy Basics The Polar Axis Finder The Polar Axis Finder is designed to minimize polar alignment time while maintaining maximum accuracy. The installation of this accessory is de- scribed in the section on “ Installing the Polar Axis Finder. ” Here ’ s how to use it: 1. Wait until it is dark enough to see Polaris with the unaided e[...]

Astronomy Basics • 35 Declination Drift This method of polar alignment allows you to get the most accurate alignment on the celestial pole and is required if you want to do long exposure deep-sky astrophotography through the telescope. The declination drift method requires that you monitor the drift of selected guide stars. The drift of each guid[...]

36 • Astronomy Basics Before you can use the setting circles to find objects in the sky, you need to align both the R.A. and DEC setting circles. In order to align the setting circle, you need to know the names of a few of the brightest stars in the sky. If you don ’ t, they can be learned by using the Celestron Sky Maps (#93722) or consulting [...]

Using the Drive • 37 Figure 5-1 The CI-700 electronic console. Powering Up the Drive USING THE DRIVE The drive system uses a 5.625 diameter bronze gear with 180 teeth for incred- ibly accurate tracking. One of the most unique features of the drive is the Periodic Error Correction (PEC) function. This feature allows the drive system to “ learn ?[...]

38 • Using the Drive This function allows you to select the speed at which the motor moves when corrections are made via the hand controller. Once the drive is activated, the default setting is .3 times sidereal rate. Press the Speed button to change the guiding rate. The selections are .3x, .5x, 8x, and 16x sidereal rate. For guiding, use either[...]

Using the Drive • 39 RATE The BC (Backlash Correction) function allows you to eliminate the backlash in the DEC motor when changing directions (i.e., from north to south or vice versa). Here ’ s how it works. Each time you change the direction of the telescope in declination, the motor speeds up momentarily to take up any slack. The Tracking Ra[...]

40 • Using the Drive 12 V DC 5. Press the “ PEC ” button once to activate the mode. The LED will flash once a second for 5 seconds indicating you have five seconds to get back to the eyepiece and begin guiding before it begins recording. The .3x guiding rate is best for this function. N O T E : The star should stay centered on the cross hairs[...]

Using the Drive • 41 The Hand Controller When using your Celestron CM-1100 in the southern hemisphere, there is a need to reverse the motors. Changing from northern hemisphere to southern hemisphere requires changing the polarity of the drive motor by changing the settings of the dip switches on the electronics board. To do this: 1. Remove the co[...]

42 • Using the Drive R.A./DEC Reverse As mentioned previously, the direction a particular button moves the mount varies depending on the telescope ’ s orientation (i.e., whether it ’ s on the east or west side of the mount). This can create confusion when guiding if you change the telescope ’ s orientation during a given photographic sessio[...]

Celestial Observing • 43 CELESTIAL OBSERVING With your telescope set up, you are ready to use it for observing. This section covers visual observing of both solar system and deep-sky objects. In the night sky, the Moon is a prime target for your first look because it is extremely bright and easy to find. Often, it is a temptation to look at the M[...]

44 • Celestial Observing Although overlooked by many amateur astronomers, solar observation is both rewarding and fun. However, 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. WARNING: Never project an image of the Sun through the telescope. Because of the fo[...]

Celestial Observing • 45 Deep-sky objects are simply those objects outside the boundaries of our solar system. They include star clusters, planetary nebulae, diffuse nebulae, double stars, and other galaxies outside our own Milky Way. The Celestron Sky Maps (#93722) can help you locate the brightest deep-sky objects. You can use your setting circ[...]

46 • Celestial Observing Star Hopping Another way to find deep-sky objects is by star hopping. Star hopping is done by using bright stars to “ guide ” you to an object. Here are the directions for two popular objects. The Andromeda Galaxy, M31, is an easy target. To find M31: 1. Locate the constellation of Pegasus, a large square visible in t[...]

Celestial Observing • 47 Star hopping may take some getting used to since you can see more stars through the finder than you can see with the naked eye. And, some objects are not visible in the finder. One such object is M57, the famed Ring Nebula. Here ’ s how to find it: 1. Find the constellation of Lyra, a small parallelogram visible in the [...]

48 • Celestial Observing Viewing conditions affect what you can see through your CM-1100 telescope during an observing session. Conditions include transparency, sky illumina- tion, and seeing. Understanding viewing conditions and the effect they have on observing will help you get the most out of your CM-1100 telescope. Transparency Transparency [...]

Celestial Observing • 49 Type 2 seeing conditions do move as quickly as Type 1, though the image is quite blurry. Fine detail is lost and the contrast is low for extended objects. Stars are spread out and not sharp. The source of Type 2 seeing is the lower atmosphere, most likely heat waves from the ground or buildings. To avoid the problems asso[...]

50 • Celestial Photography CELESTIAL PHOTOGRAPHY After looking at the night sky for awhile you may want to try photographing it. Several forms of celestial photography are possible with your Celestron CM- 1100 telescope. The most common forms of celestial photography, in order of difficulty are; short exposure prime focus, piggyback, eyepiece pro[...]

Celestial Photography • 5 1 Short exposure prime focus photography is the best way to begin recording celestial objects. It is done with the camera attached to the telescope without an eyepiece or camera lens in place. To attach your camera you need the Celestron T-Adapter (#93633-A) and a T-Ring for your specific camera (i.e., Minolta, Nikon, Pe[...]

52 • Celestial Photography The exposure times listed here should be used as a starting point. Always make exposures that are longer and shorter than the recommended time. Also, try bracketing your exposures, taking a few photos at each shutter speed. This will ensure that you will get a good photo. Keep accurate records of your exposures. This in[...]

Celestial Photography • 5 3 The easiest way to enter the realm of deep-sky, long exposure astrophotogra- phy is via the piggyback method. Piggyback photography is done with a camera and its normal lens riding on top of the telescope. Through piggyback photography you can capture entire constellations and record large scale nebulae that are too bi[...]

54 • Celestial Photography The exposure time depends on the film being used. However, five minutes is usually a good starting point. With slower films, like 100 ISO, you can expose as long as 45 minutes. With faster films, like 1600 ISO, you really shouldn ’ t expose more than 5 to 10 minutes. When getting started, use fast films to record as m[...]

Celestial Photography • 5 5 This form of celestial photography is designed for objects with small angular sizes, primarily the Moon and planets. Planets, although physically quite large, appear small in angular size because of their great distances. Moderate to high magnification is, therefore, required to make the image large enough to see any d[...]

56 • Celestial Photography The following table lists exposures for eyepiece projection with a 10mm eyepiece. All exposure times are listed in seconds or fractions of a second. The exposure times listed here should be used as a starting point. Always make exposures that are longer and shorter than the recommended time. Also, try bracketing your ex[...]

Celestial Photography • 5 7 This is the last form of celestial photography to be attempted after others have been mastered. It is intended primarily for deep-sky objects, that is objects outside our solar system which includes star clusters, nebulae, and galaxies. While it may seem that high magnification is required for these objects, just the o[...]

58 • Celestial Photography When getting started, use fast films to record as much detail in the shortest possible time. Here are proven recommendations: • Ektar 1000 (color print) • Konica 3200 (color print) • Fujichrome 1600D (color slide) • 3M 1000 (color slide) • T-Max 3200 (black and white print) • T-Max 400 (black and white print[...]

Celestial Photography • 5 9 Fastar Lens Assembly Option – Using your CM-1400 telescope at f/2.1 with optional PixCel CCD Camera Only the CM-1400 is equipped with a removable secondary mirror that allows you to convert your f/11 telescope into an f/2.1 imaging system capable of exposure times 25 times shorter than those needed with a f/11 system[...]

60 • Celestial Photography The F/# stands for the ratio between the focal length and the diameter of the light gathering element. A C14 optical tube has a focal length of 154 inches and a diameter of 14 inches. This makes the system an f/11, (focal length divided by diameter). When the secondary is removed and the CCD is placed at the Fastar posi[...]

Celestial Photography • 6 1 When imaging some objects like planetary nebula (for example M57, the Ring Nebula) and small galaxies (M104, the Sombrero Galaxy), larger image scale is needed to resolve finer detail. These objects are better shot at f/7 or even f/ 11. Medium size to small galaxies -- f/7 imaging gives you finer resolution then at f/2[...]

62 • Celestial Photography 2 3 1 4 5 3 6 8 9 7 13 12 14 11 10 15 18 16 17 19 10 9 20 24 21 20 22 19 10 23 Planetary or Lunar-- f/20 is a great way to image the planets and features on the moon. With the PixCel CCD camera and optional Color Filter Wheel, it is easy to take tri-color images of planets also. When imaging the planets, very short expo[...]

Telescope Maintenance • 6 3 TELESCOPE MAINTENANCE While your CM-1100 telescope requires little maintenance, there are a few things to remember that will ensure your telescope performs at its best. Occasionally, dust and/or moisture may build up on the corrector plate of your telescope. Special care should be taken when cleaning any instrument so [...]

64 • Telescope Maintenance spheric distortion. Turn your telescope drive on so that you won ’ t have to manually track the star. Or, if your are not using the clock drive, use Polaris. Its position relative to the celestial pole means that it moves very little thus eliminating the need to manually track it. Before you begin the collimation proc[...]

Telescope Maintenance • 6 5 6 Once the star image is in the center of the field of view, check to see if the rings are concentric. If the central obstruction is still skewed in the same direction, then continue turning the screw(s) in the same direction. If you find that the ring pattern is skewed in a different direction, than simply repeat step[...]

66 • Optional Accessories OPTIONAL ACCESSORIES The following is a partial list of optional accessories available for your Celestron CM-1100/1400. You will find that additional accessories enhance your viewing pleasure and expand the usefulness of your telescope. For ease of reference, all the accessories are listed in alphabetical order. AC Adapt[...]

Optional Accessories • 67 prism arrangement that, in addition to producing correctly oriented images, allows you to look into the telescope at a 45 ° angle, a desirable arrangement for terrestrial viewing. Eyepiece Filters - To enhance your visual observations of planetary objects, Celestron offers a wide range of colored filters that thread int[...]

68 • Optional Accessories in the main telescope. Flashlight (#93592) - The LED flashlight uses a red LED to allow reading star maps without ruining your night vision. The LED flashlight is small, only 6 inches long, and weighs in at a mere 3 ounces. Flashlight, Night Vision (#93588) - Celestron ’ s premium model for as- tronomy, using two red L[...]

Optional Accessories • 69 prime focus long-exposure astrophotography. It makes guiding easier and exposures shorter. Sky Maps (#93722) - When learning the night sky, the Celestron Sky Maps offer the ideal solution. The maps include all the constellations and brighter deep-sky objects. The maps are printed on a heavy stock paper that is moisture-r[...]

70 • The Messier Catalog THE MESSIER CATALOG The Messier Catalog, compiled by Charles Messier, was the first extensive listing of star clusters and nebulae. Messier ’ s primary observational purpose was to discover comets. He compiled this list so that others searching for comets would not be confused by these objects. His list still remains po[...]

The Messier Catalog • 71 M# NGC# Const. R.A. D E C M ag Type Proper Name H M S ° ‘ M3 6 NGC 1960 Au r 5 36.3 34 08 6. 0 Op. Cl. M3 7 NGC 2099 Au r 5 52.0 32 33 5. 6 Op. Cl. M3 8 NGC 1912 Au r 5 28.7 35 50 6. 4 Op. Cl. M3 9 NGC 7092 Cyg 21 32.3 48 26 4 .6 Op. Cl. M 4 0 U M a 12 22.2 58 05 8 .0 db l M4 1 NGC 2287 CM a 6 47.0 -20 44 4. 5 Op. Cl. [...]

72 • The Messier Catalog M# NGC# Const. R.A. D E C M ag Type Proper Name H M S ° ‘ M8 1 NGC 3031 U M a 9 55.8 69 04 6 .8 Sp. Gx. Bodes Nebula M8 2 NGC 3034 U M a 9 56.2 69 41 8 . 4 Ir. Gx. M8 3 NGC 5236 Hya 13 37.7 -29 52 7.6 Sp. Gx. M8 4 NGC 4374 Vir 1 2 25.1 12 53 9 .3 El. Gx. M8 5 NGC 4382 C o m 12 25.4 18 11 9.2 El. Gx. M8 6 NGC 4406 Vir 1[...]

List of Bright Stars • 73 LIST OF BRIGHT STARS The following is a list of bright stars that can be used to align the R.A. setting circle. All coordinates are in epoch 2000.0. Epoch 2000.0 Star Name Constellation R.A. D E C Magnitude H M S ° ‘ “ Sirius C M a 06 45 09 -16 42 58 -1.47 Canopus C a r 06 2 3 5 7 -5 2 4 1 44 -0.72 Arcturus Bo o 14 [...]

FOR FURTHER READING The following is a list of astronomy books that will further enhance your understanding of the night sky. The books are broken down by classification for easy reference. Astronomy Texts Astronomy Now ......................................................................................... Pasachoff & Kutner Cambridge Atlas O[...]

CELESTRON ONE YEAR W ARRANTY A . Celestron International (CI) warrants this telescope to be free from defects in materials and workmanship for one year. CI w ill repair or replace such product or part thereof which, upon inspection by CI, is found to be defective in materials or workmanship. As a condition to the obligation of CI to repair or repla[...]

Celestron International 2835 Columbia Street T orrance, CA 90503 T el: 310-328-9560 Fax: 310-212-5835 W eb site: http://www .celestron.com Copyright 1998 Celestron International All right reserved (Products or instructions may change without notice or obligation). Item #1 1055-INST 07-98 Price $10.00[...]