Observation
Observing by Moving the Telescope Manually
After the telescope is assembled and balanced as described previously,
you are ready to begin manual observations. View easy-to-find terrestrial
objects such as street signs or traffic lights to become accustomed to the
functions and operations of the telescope. For the best results during
observations, follow the suggestions below:
• When you wish to locate an object to observe, first loosen the
telescope’s R.A. lock (33, Fig. 1d) and Dec. lock (17, Fig. 1d). The
telescope can now turn freely on its axes. Unlock each axis separately
and practice moving your telescope. Then practice with two unlocked
axes at the same time. It is very important to practice this step to
understand how your telescope moves, as the movement of an
equatorial mount is not intuitive.
• Use the aligned viewfinder to sight-in on the object you wish to observe.
When the object is centered in the viewfinder’s crosshairs, re-tighten the
R.A. and Dec. locks.
• A telescope’s eyepiece magnifies the image formed by the telescope’s
main optics. Each eyepiece has a focal length, expressed in millimeters, or
“mm.” The smaller the focal length, the higher the magnification. For
example, an eyepiece with a focal length of 9mm has a higher
magnification than an eyepiece with a focal length of 25mm. Low-power
magnification eyepieces offer a wide field of view, bright, high-contrast
images, and relief of eye strain during long observing sessions. To observe
an object with a telescope, always start with a low power eyepiece such as
the 25mm supplied with your telescope. When the object is centered and
focused in the eyepiece, switch to a higher power eyepiece to enlarge the
image as much as practical for prevailing viewing conditions.
• Once centered, an object can be focused by turning one of the knobs of
the focusing mechanism (8, Fig. 1b). Notice that when observing
astronomical objects, the field of view begins to slowly drift across the
eyepiece field. This motion is caused by the rotation of the Earth on its
axis. Objects appear to move through the field more rapidly at higher
powers. This can be compensated with the RA drive shaft or the
(optional) RA drive motor.
Observe the Moon
Point your telescope at the Moon (note that the Moon is not visible every
night). The Moon contains many interesting features, including craters,
mountain ranges, and fault lines. The best time to view the Moon is during
its crescent or half phase. Sunlight strikes the Moon at an angle during
these periods and adds a depth to the view. No shadows are seen during a
full Moon, making the overly bright surface to appear flat and rather
uninteresting. Consider the use of a neutral density Moon filter when
observing the Moon. Not only does it cut down the Moon's bright glare,
but it also enhances contrast, providing a more dramatic image.
Looking at or near the Sun will cause instant and irreversible damage to your eye!
14
OBSERVATION
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Objects appear upside-down and
reversed left-for-right when observed
in the viewfinder. With refracting tele-
scope models, objects viewed through
the main telescope with the diagonal
mirror in place are seen right-side-up,
but reversed left-for-right. This image
inversion is of no consequence when
observing astronomical objects, and in
fact all astronomical telescopes yield
inverted images.
WWAARRNNIINNGG
Never use a Telescope to look at the
Sun! Looking at or near the Sun will
cause instant and irreversibledamage
to your eye. Eye damage is often pain-
less, so there is no warning to theob-
server that damage has occurred until
it is too late. Do not point the telesco-
pe or its viewfinder at or near the Sun.
Do not look through the telescope or
its viewfinder as it is moving. Children
should always have adult supervision
while observing.
