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6

5. With one hand on the telescope optical tube, loosen the

Dec. lock lever. The telescope should now be able to rotate
freely about the declination axis.

6. Loosen the knurled ring clamps on the tube rings a few

turns, until you can slide the telescope tube forward and
back inside the rings (this can be aided by using a slight
twisting motion on the optical tube while you push or pull
on it) (Figure 5c).

7. Position the telescope in the tube rings so it remains hori-

zontal when you carefully let go with both hands. This is
the balance point for the optical tube with respect to the
Dec. axis (Figure 5d).

8. Retighten the knurled rings clamps.

The telescope is now balanced on both axes. When you
loosen the lock lever on one or both axes and manually point
the telescope, it should move without resistance and should
not drift from where you point it.

5. Using Your Telescope

Focusing the Telescope

With the 25mm eyepiece inserted in the focuser, loosen the
R.A. and Dec. lock levers and move the telescope so the front
(open) end is pointing in the general direction of an object at
least 1/4-mile away. Now, with your fingers, slowly rotate one
of the focusing knobs until the object comes into sharp focus.
Go a little bit beyond sharp focus until the image just starts to
blur again, then reverse the rotation of the knob, just to make
sure you’ve hit the exact focus point.

NOTE: The image in the telescope will appear rotated
180° (upside down and reversed left-to-right). This is nor-
mal for astronomical scopes. The finder scope view will
also be rotated 180° (see Figure 6).

If you have trouble focusing, rotate the focusing knob so the
drawtube is in as far as it will go. Now look through the eyepiece
while slowly rotating the focusing knob in the opposite direction.
You should soon see the point at which focus is reached.

The black nylon thumbscrew on the top of the body of the
focuser (see Figure 4) will lock the focuser drawtube in place
once the telescope is properly focused. Before focusing,
remember to first loosen this thumbscrew.

Viewing with Eyeglasses

If you wear eyeglasses, you may able to keep them on while
you observe, if the eyepiece has enough “eye relief” to allow
you to see the whole field of view. You can try this by looking
through the eyepiece first with your glasses on, and then with
them off, and see if the glasses restrict the view to only a por-
tion of the full field. If they do, you can easily observe with your
glasses off by just re-focusing the telescope the needed
amount. If you suffer from severe astigmatism, however, you
may find images noticeably sharper with your glasses on.

Aligning the Finder Scope

The Atlas 8 EQ Deluxe comes with a 6x30 achromatic finder
scope (Figure 3a). The number 6 means six-times magnifica-
tion and the 30 indicates a 30mm diameter front lens. The
finder scope makes it easier to locate the subject you want to
observe in the telescope, because the finder scope has a
much wider field-of-view.

The Atlas 8 EQ’s finder scope uses a spring-loaded bracket that
makes alignment of the finderscope very easy. As you turn
either of the thumbscrews, the spring in the bracket’s tensioner
moves in and out to keep the finder scope secure in the bracket.

The finder scope must be aligned accurately with the tele-
scope for proper use. To align it, first aim the main telescope
in the general direction of an object at least a 1/4 mile away—
the top of a telephone pole, a chimney, etc; loosen the R.A.
and Dec. lock levers and move it until it is pointing at the
desired object. Then sight along the tube to precisely aim the
telescope. Turn the focus knob until the object is properly
focused. Retighten the R.A. and Dec. lock levers.

Now look in the finder scope. Is the object visible? Ideally it will
be somewhere in the field of view. If not, some coarse adjust-
ment to the finder scope bracket’s alignment thumbscrews will
be needed until the object comes into the finder scope’s field
of view.

With the image in the finder scope’s field of view, you now
need to fine-adjust the alignment thumbscrews to center the
object on the intersection of the crosshairs. Adjust the aim of
the finder scope by turning the thumbscrews, one at a time,
until the object is centered.

The finder scope alignment needs to be checked before every
observing session. This can easily be done at night, before
viewing through the telescope. Choose any bright star or plan-
et, center the object in telescope eyepiece, and then adjust
the finder scope bracket’s alignment thumbscrews until the
star or planet is centered on the finder’s crosshairs.

Focusing the finder scope

If, when you look through the finder scope, the images appear
somewhat out of focus, you will need to refocus the finder
scope for your eyes. Loosen the lock ring located behind the
objective lens cell on the body of the finder scope (see Figure

Naked-eye view

View through finder scope and telescope

Figure 6. 

The view through a standard finder scope and reflector

telescope is rotated 180°. This is true for the Atlas 8 EQ and its
finder scope as well.

Summary of Contents for Atlas 8 EQ 9873

Page 1: ...03 Providing Exceptional Consumer Optical Products Since 1975 Customer Support 800 676 1343 E mail support telescope com Corporate Offices 831 763 7000 P O Box 1815 Santa Cruz CA 95061 Orion Atlas 8 EQ 9873 Equatorial Reflector Telescope ...

Page 2: ...haft lock lever Counterweight shaft Counterweights Counterweight lock knobs Toe Saver Tripod leg Leg lock lever Finder scope Finder scope bracket Eyepiece Focus knob Tube rings Right ascension setting circle Right ascension lock lever Mirror cell Latitude scale Latitude adjustment L bolts Center support shaft not shown Hand controller Tripod support tray ...

Page 3: ...ray Box 2 1 Equatorial mount 1 Hand controller 1 Battery pack 1 Nylon hook and loop adhesive strip Box 3 1 Optical tube 2 Tube rings 1 Tube ring mounting plate 1 25mm Sirius Plössl eyepiece 1 10mm Sirius Plössl eyepiece 1 9x50 Finder scope 1 Finder scope bracket with O ring 1 Collimation cap 1 Camera adapter 1 Dust cover Congratulations on your purchase of a quality Orion telescope Your new Atlas ...

Page 4: ...rweight lock knobs are adequately loosened to allow the counterweight shaft to pass through the hole Position the counterweights about halfway up the shaft and tighten the lock knobs Replace the toe saver at the end of the bar The toe saver prevents the counterweights from falling on your foot if the lock knobs happen to come loose 7 Loosen and open the tube rings on the optical tube and remove th...

Page 5: ...nt is very heavy Alone it weighs 54 lbs With the optical tube and counterweights it weighs almost 100 lbs Keep this in mind when moving the telescope even small distances and use assistance when needed It is best to remove the optical tube and counterweights when moving the mount or extending the tripod legs 4 Balancing the Telescope To ensure smooth movement of the telescope on both axes of the e...

Page 6: ...serve with your glasses off by just re focusing the telescope the needed amount If you suffer from severe astigmatism however you may find images noticeably sharper with your glasses on Aligning the Finder Scope The Atlas 8 EQ Deluxe comes with a 6x30 achromatic finder scope Figure 3a The number 6 means six times magnifica tion and the 30 indicates a 30mm diameter front lens The finder scope makes...

Page 7: ...may want to increase the magnifi cation to get a closer view If the object is off center i e it is near the edge of the field of view you will lose it when you increase magnification since the field of view will be narrower with the higher powered eyepiece To change eyepieces first loosen the securing thumbscrew on the focuser s 1 25 adapter Then carefully lift the eyepiece out of the holder Do no...

Page 8: ...tments to the latitude of the mount nor should you move the tripod Doing so will undo the polar align ment The telescope should be moved only about its R A and Dec axes Using the Polar Axis Finder Scope The Atlas EQ mount comes with a polar axis finder scope Figure 9 housed inside the right ascension axis of the mount When properly aligned and used it makes accurate polar alignment quick and easy ...

Page 9: ...e tiny circle marked Polaris on the finder s reticle You must first loosen the knob under neath the equatorial mount on the center support shaft to use the azimuth adjustment knobs Once Polaris is proper ly positioned within the reticle you are precisely polar aligned Retighten the knob underneath the mount If you do not have a clear view of Polaris from your observing site you will not be able to...

Page 10: ...tches one for the R A axis and one for the Dec axis When these switches are flipped to the REV setting the function of the pushbuttons on the hand controller will be reversed The reversal switches allow you to orient the push buttons to the direction of the apparent movement of a guide star in a guide scope for astrophotography Understanding the Setting Circles The setting circles on an equatorial...

Page 11: ...ience some confusion about how to point the telescope overhead or in other directions In Figure 1 the telescope is pointed north as it would be during polar alignment The counterweight shaft is oriented down ward But it will not look like that when the telescope is point ed in other directions Let s say you want to view an object that is directly overhead at the zenith How do you do it DO NOT make...

Page 12: ...ersely affects the optical performance of the tele scope or the image quality That might seem counter intuitive but its true Aligning the Secondary Mirror With the collimation cap in place look through the hole in the cap at the secondary diagonal mirror Ignore the reflections for the time being The secondary mirror itself should be cen tered in the focuser drawtube in the direction parallel to th...

Page 13: ...ck the primary mirror in place a few turns each Figure 17 Use a screwdriv er in the slots if necessary Now try tightening or loosening one of the larger collimation thumbscrews with your fingers Figure 18 Look into the focuser and see if the secondary mirror reflection has moved closer to the center of the primary You can tell this easily with the collimation cap and mirror center mark by simply w...

Page 14: ...nt of distortion causing atmosphere you are looking through A good way to judge if the seeing is good or not is to look at bright stars about 40 above the horizon If the stars appear to twinkle the atmosphere is significantly distorting the incom ing light and views at high magnifications will not appear sharp If the stars appear steady and do not twinkle seeing conditions are probably good and hi...

Page 15: ... The Moon also takes higher magnifications well Deep sky objects however typically look better at medium or low magnifications This is because many of them are quite faint yet have some extent apparent width Deep sky objects will often disappear at higher magnifications since greater magnification inherently yields dimmer images This is not the case for all deep sky objects however Many galaxies a...

Page 16: ...telescopes cannot magnify stars to appear as more than a point of light You can however enjoy the different colors of the stars and locate many pretty double and multiple stars The famous Double Double in the constellation Lyra and the gorgeous two color double star Albireo in Cygnus are favorites Defocusing a star slightly can help bring out its color Deep Sky Objects Under dark skies you can obs...

Page 17: ...he focuser drawtube Figure 22a Then screw the camera adapter into the focuser drawtube Figure 22b Now attach the T Ring to your camera and thread it onto the camera adapter Figure 22c Use the camera s viewfinder to frame the picture Use the tele scope s focuser to focus the image You may want to consider using a remote shutter release instead of the shutter release on the camera touching the camer...

Page 18: ...ill need a lock shutter release cable Set the camera s shutter to the B bulb setting Depress the locking shutter release cable and lock it You are now expos ing your first deep sky object While exposing through the camera lens you will need to monitor the accuracy of the mount s tracking by looking through the illuminated reticle eyepiece in the main telescope If the guide star drifts from its ini...

Page 19: ... a few minutes or hours if it s a very dirty mirror Wipe the mirror under water with clean cotton balls using extremely light pressure and stroking in straight line across the mirror Use one ball for each wipe across the mirror Then rinse the mirror under a stream of lukewarm water Any particles on the surface can be swabbed gently with a series of cotton balls each used just one time Dry the mirr...

Page 20: ...Watsonville CA 95076 If the product is not registered proof of purchase such as a copy of the original invoice is required This warranty does not apply if in Orion s judgment the instrument has been abused mishan dled or modified nor does it apply to normal wear and tear This warranty gives you specific legal rights and you may also have other rights which vary from state to state For further war ...

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