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13

of the secondary mirror. This is done by alternately loosening
one of the three alignment set screws while tightening the
other two, as depicted in Figure 16. The goal is to center the
primary mirror reflection in the secondary mirror, as in Figure
14d. Don’t worry that the reflection of the secondary mirror
(the smallest circle, with the collimation cap “dot” in the cen-
ter) is off-center. You will fix that in the next step.

Adjusting the Primary Mirror

The final adjustment is made to the primary mirror. It will need
adjustment if, as in Figure 14d, the secondary mirror is cen-
tered under the focuser and the reflection of the primary mir-
ror is centered in the secondary mirror, but the small reflection
of the secondary mirror (with the “dot” of the collimation cap)
is off-center.

The tilt of the primary mirror is adjusted with three spring-
loaded collimation thumbscrews on the back end of the opti-
cal tube (bottom of the primary mirror cell); these are the larg-
er thumbscrews. The other three smaller thumbscrews lock
the mirror’s position in place; these thumbscrews must be
loosened before any collimation adjustments can be made to
the primary mirror.

To start, turn the smaller thumbscrews that lock 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 watching
to see if the “dot” of the collimation cap is moving closer or fur-
ther away from the “ring” on the center of the primary mirror
mark. When you have the dot centered as much as is possible
in the ring, your primary mirror is collimated. The view through
the collimation cap should resemble Figure 15e. Re-tighten
the locking thumbscrews.

A simple star test will tell you whether the optics are accurate-
ly collimated.

Figure 15. 

To center the secondary mirror under the focuser,

hold the secondary mirror holder in place with one hand while
adjusting the center bolt with a Phillips screwdriver. Do not touch the
mirror’s surface!

Figure 16. 

Adjust the tilt of the secondary mirror by loosening or

tightening the three alignment set screws with a 2mm hex key.

Figure 17. 

The three small thumbscrews that lock the primary

mirror in place must first be loosened before any adjustments can
be made.

Figure 18. 

The tilt of the primary mirror is adjusted by turning

one or more of the three larger thumbscrews.

Содержание Atlas 8 EQ 9873

Страница 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 ...

Страница 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 ...

Страница 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 ...

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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 ...

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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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