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6

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ointing your telescope

Pointing an altitude-azimuth (alt-az) mounted telescope is relatively easy. With the mount level, you can swivel 
the telescope around on a plane parallel to your horizon and then tilt it up and down from there (Fig.c). You can 
think of it as turning your telescope in azimuth until it is facing the horizon below a celestial object and then 
tilting it up to the object's altitude. However, the Earth rotates and therefore the stars are constantly moving, 
so to track with this mount you need to constantly nudge the optical tube in both azimuth and altitude to keep 
the object in the field.

In reference material for your local position, the altitude will be listed as ±degrees (minutes, seconds) above 
or below your horizon. Azimuth may be listed by the cardinal compass points such as N, SW, ENE, etc., but 
it is usually listed in 360 degree (minutes, seconds) steps clockwise from North (0°), with East, South and 
West being 90°, 180° and 270 °, respectively (Fig.d).

Fig.d

Rotate in Azimuth

(90°)

(180°)

S

E

(270°)

W

Zenith

Meridian 
Line

Tilt in 
Altitude

Nadir

(0°/360°)

N

Summary of Contents for 709AZ3

Page 1: ...ove before viewing Dew Cap Sun Shade Objective Lens Tube Rings Accessory Tray Tripod Leg Height Adjustment Clamp Piggyback Bracket Finderscope Finderscope Bracket Finderscope Allignment Screw Focus Tube Focus Locking Screw Eyepiece Diagonal Focus Knobs Altitude Flexible Control Cable Azimuth Flexible Control Cable ...

Page 2: ... 5 3 3 4 4 4 5 5 5 6 7 7 7 8 8 8 8 8 8 9 TABLE OF CONTENTS Read the entire instructions carefully before beginning Your telesope should be assembled during daylight hours Choose a large open area to work to allow room for all parts to be unpackaged Before you begin Never use your telescope to look directly at the sun Permanent eye damage will result Use a proper solar filter for viewing the sun Wh...

Page 3: ...e wingnuts and damage tripod legs Fig 3 Fig 2 TRIPOD SET UP ATTACHING THE TELESCOPE MAIN TUBE TO TUBE RINGS Fig 5 1 Remove the telescope tube from the paper covering 2 Place telescope tube in between the two tube rings Close the hinges around the telescope and fasten securely by tightening the thumb nuts without over tightening ATTACHING THE TUBE RINGS TO MOUNT Fig 4 1 Remove the tube rings multif...

Page 4: ...e two knurled thumbscrews These fixed magnification scopes mounted on the optical tube are very useful accessories When they are correctly aligned with the telescope objects can be quickly located and brought to the centre of the field Alignment is best done outdoors in day light when it s easier to locate objects If it is necessary to refocus your finderscope sight on an object that is at least 5...

Page 5: ...he number of eyepiece in your collection Focusing Fig c Slowly turn the focus knobs under the focuser one way or the other until the image in the eyepiece is sharp Fig c The image usually has to be finely refocused over time due to small variations caused by temperature changes flexures etc This often happens with short focal ratio telescopes particularly when they haven t yet reached outside temp...

Page 6: ... and therefore the stars are constantly moving so to track with this mount you need to constantly nudge the optical tube in both azimuth and altitude to keep the object in the field In reference material for your local position the altitude will be listed as degrees minutes seconds above or below your horizon Azimuth may be listed by the cardinal compass points such as N SW ENE etc but it is usual...

Page 7: ... bit from person to person is less until your eyes become fully dark adapted and decreases as you get older To determine an exit pupil you divide the diameter of the primary of your telescope in mm by the magnification For example a 200mm f 5 telescope with a 40mm eyepiece produces a magnification of 25x and an exit pupil of 8mm This combination can probably be used by a young person but would not...

Page 8: ... also affects images Astronomy is an outdoor activity The best conditions will have still air and obviously a clear view of the sky It is not necessary that the sky be cloud free Often broken cloud conditions provide excellent seeing Do not view immediately after sunset After the sun goes down the Earth is still cooling causing air turbulence As the night goes on not only will seeing improve but a...

Page 9: ...s New York 1984 Astrophotography An Introduction by H J P Arnold Sky Publishing Corp Cambridge MA Sky Telescope Observer s Guides Series ed Leif J Robinson 1995 Observational References Magazines Astrophotography for the Amateur by Michael Covington Cambridge University Press Cambridge UK 2nd edition 1999 Splendors of the Universe A Practical Guide to Photographing the Night Sky by Terence Dickins...

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