6
5. using Your telescope
Focusing the telescope
With the 25mm eyepiece inserted in the focuser, 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 normal
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 eye-
piece while slowly rotating the focusing knob in the opposite
direction. You should soon see the point at which focus is
reached.
The black nylon thumb screw 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 thumb screw.
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 look-
ing through the eyepiece first with your glasses on, and then
with them off, and see if the glasses restrict the view to only a
portion 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 SkyView Pro 8 EQ Deluxe comes with a 8x40 achromatic
finder scope (Figure 3a). The number 8 means eight-times mag-
nification and the 40 indicates a 40mm 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 SkyView Pro 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 telescope
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. To aim the telescope, 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 aim the telescope.
Turn the focus knob until the object is properly focused. Make
sure to position the object in the center of the telescope’s eye-
piece by turning the R.A. and Dec. slow-motion control knobs.
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 planet,
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
3a). Back the lock ring off by a few turns, for now. Refocus the
finder scope on a distant object by threading the objective lens
cell in or out of the finderscope body. Precise focusing will be
achieved by focusing the finder scope on a bright star. Once
the image appears sharp, retighten the locking ring behind the
objective lens cell. The finder scope’s focus should not need
to be adjusted again.
Magnification & Eyepieces
Magnification, or power, is determined by the focal length of
the telescope and the focal length of the eyepiece. Therefore,
by using eyepieces of different focal lengths, the resultant
magnification can be varied.
Magnification is calculated as follows:
Telescope Focal Length (mm)
= Magnification
Eyepiece Focal Length (mm)
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 SkyView Pro 8 EQ and
its finder scope as well.