background image

more heat, which disturbs the surrounding air and degrades
the images seen through the telescope. Avoid viewing over
rooftops and chimneys, as they often have warm air currents
rising from them. Similarly, avoid observing from indoors
through an open (or closed) window, because the tempera-
ture difference between the indoor and outdoor air will cause
image blurring and distortion.

If at all possible, escape the light-polluted city sky and head
for darker country skies. You’ll be amazed at how many more
stars and deep-sky objects are visible in a dark sky! 

“Seeing” and Transparency

Atmospheric conditions vary significantly from night to night.
“Seeing” refers to the steadiness of the Earth’s atmosphere at
a given time. In conditions of poor seeing, atmospheric turbu-
lence causes objects viewed through the telescope to “boil”.
If, when you look up at the sky with your naked eyes, the
stars are twinkling noticeably, the seeing is bad and you will
be limited to viewing with low powers (bad seeing affects
images at high powers more severely). Planetary observing
may also be poor.

In conditions of good seeing, star twinkling is minimal and
images appear steady in the eyepiece. Seeing is best over-
head, worst at the horizon. Also, seeing generally gets better
after midnight, when much of the heat absorbed by the Earth
during the day has radiated off into space.

Especially important for observing faint objects is good
“transparency”air—free of moisture, smoke, and dust. All
tend to scatter light, which reduces an object’s brightness.
Transparency is judged by the magnitude of the faintest stars
you can see with the unaided eye (6th magnitude or fainter is
desirable).

If you cannot see stars of magnitude 3.5 or dimmer then con-
ditions are poor. Magnitude is a measure of how bright a star
is—the brighter a star is, the lower its magnitude will be. A
good star to remember for this is Megrez (mag. 3.4), which is
the star in the “Big Dipper” connecting the handle to the “dip-
per”. If you cannot see Megrez, then you have fog, haze,
clouds, smog, or other conditions that are hindering your
viewing (See Figure 11).

Eyepiece Selection

By using eyepieces of different focal lengths, it is possible to
attain many magnifications or powers with the Observer
60mm. Your telescope comes with two Kellner eyepieces
(Figure 12): a 25mm, which gives a magnification of 36x, and
a 10mm, which gives a magnification of 90x. Other eyepieces
can be used to achieve higher or lower powers. It is quite
common for an observer to own five or more eyepieces to
access a wide range of magnifications.

To calculate the magnification, or power, of a telescope-eye-
piece combination, simply divide the focal length of the tele-
scope by the focal length of the eyepiece.

Telescope Focal Length (mm)

= Magnification 

Eyepiece Focal Length (mm)

For example, the Observer 60mmEQ , which has a focal
length of 900mm, used in combination with the 25mm eye-
piece, yields a magnification of 

900mm

= 36x

25mm

Whatever you choose to view, always start by inserting your
lowest-power (longest focal length) eyepiece to locate and
center the object. Low magnification yields a wide field of
view, which shows a larger area of sky in the eyepiece. This
makes finding and centering an object much easier. Trying to
find and center objects with a high power (narrow field of
view) eyepiece is like trying to find a needle in a haystack!

Once you’ve centered the object in the eyepiece, you can
switch to a higher magnification (shorter focal length) eye-
piece, if you wish. This is recommended for small and bright
objects, like planets and double stars. The Moon also takes
higher magnifications well.

The best rule of thumb with eyepiece selection is to start with
a low power, wide-field eyepiece, and then work your way up
in magnification. If the object looks better, try an even higher
magnification eyepiece. If the object looks worse, then back
off the magnification a little by using a lower-power eyepiece.

Figure 11. 

Megrez connects the Big Dipper’s handle to it's “pan”.

It is a good guide to how conditions are. If you can not see Megrez
(a 3.4 mag star) then conditions are poor.

16

2.4

1.7

3.4

2.4

4.9

1.9

1.9

2.5

Figure 12. 

The 10mm and 25mm
Explorer II eyepieces.

Содержание Observer 60mm EQ

Страница 1: ...roviding 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 Observer 60mm EQ 9853 Equatorial Refractor Telescope ...

Страница 2: ...2 ...

Страница 3: ...s 7 8 3 Tripod legs 9 with attached accessory tray bracket 11 1 Accessory tray 10 with attachment wing screws 1 Counterweight shaft 25 1 Counterweight 6 1 Latitude adjustment T bolt 29 1 EZ Finder II reflex sight 4 3 Tripod leg attachment screws with wingnuts and washers 31 3 Leg lock knobs 12 1 25mm Kellner eyepiece 1 10mm Kellner eyepiece 1 90 Mirror star diagonal 2 1 Dust cover Welcome to the e...

Страница 4: ...4 2 4 8 6 7 Observer 60mm Refractor 11 10 3 9 Figure 1 Observer 60mm EQ components 5 1 12 ...

Страница 5: ...ning the Equatorial Mount section for more details Counterweight This counterweight will balance out the optical tube 1 when it is being aimed at celestial objects Right ascension slow motion control cable This cable is used to make small movements in right ascension when aiming the telescope Right ascension is explained in the Aligning the Equatorial Mount sec tion This cable is also used to trac...

Страница 6: ...Figure 2a Optical tube components 6 14 Observer 60mm Telescope Tube Figure 2b Observer 60mm focuser detail 15 3 2 17 4 1 3 2 17 10 18 19 13 16 20 ...

Страница 7: ...s a rack an pinion system to bring objects into focus Focus wheels These wheelswhen turned move the focuser drawtube 17 in or out Use it to bring things into focus when you are looking in the eyepiece 3 Diagonal holder thumbscrews These two thumbscrews secure the 90 mirror star diagonal 2 into the focuser drawtube 17 These should only be loosened to remove or rotate the star diagonal Eyepiece hold...

Страница 8: ...Figure 3a Equatorial mount detail 8 Figure 3b Observer 60mm EQ tripod leg and mount attachment detail 22 Observer 60mm Tripod and Mount 23 25 21 26 27 8 29 31 31 30 7 24 28 6 ...

Страница 9: ...atitude scale This scale gives a general indication of the latitude set ting of the equatorial mount 5 Latitude lock T bolt This T bolt must be loosened to make adjustments to the latitude of the telescope Latitude adjustment T bolt This T bolt is used to make adjustments to the latitude setting of the equatorial mount 5 Azimuth lock knob Loosening this knob will allow the equatorial to be adjuste...

Страница 10: ... and the 40 line up Then retighten the latitude lock T bolt The declination Dec and right ascension R A axes may need re posi tioning rotation as well Be sure to loosen the R A and Dec lock knobs 22 24 before doing this Retighten the R A and Dec lock knobs once the equatorial mount is properly oriented 7 Thread the counterweight shaft 25 into the equatorial mount 5 at the base of the declination a...

Страница 11: ... and should not drift from where you point it Focusing the Telescope With the 25mm Kellner eyepiece 3 inserted into the 90 mir ror star diagonal 2 and secured with the thumbscrews aim the optical tube 1 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 focus wheels 18 until the object comes into sharp focus...

Страница 12: ...them from drifting out of the telescope s field of view while you re observing This is accomplished by slowly rotating the telescope on its right ascension R A axis using only the R A slow motion cable 7 But first the R A axis of the mount must be aligned with the Earth s rotational polar axis a process called polar alignment Understanding Polar Alignment To understand what you will be doing when ...

Страница 13: ...ts roughly at Polaris If you can not see Polaris directly from your observing site consult a compass and rotate the mount so the telescope points North Retighten the azimuth lock knob The equatorial mount is now polar aligned From this point on in your observing session you should not make any further adjustments in the azimuth or the latitude of the mount nor should you move the tripod Doing so w...

Страница 14: ...itude on Earth and Dec is similar to latitude The R A and Dec values for celestial objects can be found in any star atlas or star catalog The mount s R A setting circle 23 is scaled in hours from 1 through 24 with small marks in between representing 10 minute increments The numbers closest to the R A axis gear apply to viewing in the Southern Hemisphere while the num bers above them apply to viewi...

Страница 15: ... other directions Let s say you want to view an object that is directly overhead at the zenith How do you do it One thing you DO NOT do is make any adjustment to the lat itude adjustment T bolt 29 That will nullify the mount s polar alignment Remember once the mount is polar aligned the telescope should be moved only on the R A and Dec axes To point the scope overhead first loosen the R A lock kno...

Страница 16: ...ez then you have fog haze clouds smog or other conditions that are hindering your viewing See Figure 11 Eyepiece Selection By using eyepieces of different focal lengths it is possible to attain many magnifications or powers with the Observer 60mm Your telescope comes with two Kellner eyepieces Figure 12 a 25mm which gives a magnification of 36x and a 10mm which gives a magnification of 90x Other e...

Страница 17: ...the front opening of the Observer 60mm The primary attrac tion is sunspots which change shape appearance and loca tion daily Sunspots are directly related to magnetic activity in the Sun Many observers like to make drawings of sunspots to monitor how the Sun is changing from day to day Important Note Do not look at the Sun with any optical instrument without a professionally made solar filter or p...

Страница 18: ...s in temperature and humidity Do not store the tele scope outdoors although storage in a garage or shed is OK Small components like eyepieces and other accessories should be kept in a protective box or storage case Keep the caps on the front of the telescope and on the focuser draw tube when not in use Your Observer 60mm telescope requires very little mechani cal maintenance The optical tube is al...

Страница 19: ...19 ...

Страница 20: ...ay 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 w...

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