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Telescope Terms To Know:
Diagonal: A mirror that deflects the ray of light 90 degrees.
With a horizontal telescope tube, this device deflects the light upwards so
that you can comfortably observe by looking downwards into the eyepiece.
The image in a diagonal mirror appears upright, but rotated around its
vertical axis (mirror image).
Focal length: Everything that magnifies an object via an optic lens has a certain focal length. The focal
length is the length of the path the light travels from the surface of the lens to its focal point. The focal
point is also referred to as the focus. In focus, the image is clear. In the case of a telescope, the focal
length of the telescope tube and the eyepieces are used to determine magnification.
Lens: The lens turns the light that falls on it around in such a way so that the light gives a clear image in
the focal point after it has traveled a certain distance (focal length).
Eyepiece: An eyepiece is a system made for your eye and comprised of one or more lenses. In an
eyepiece, the clear image that is generated in the focal point of a lens is captured and magnified still
more.
Magnification: The magnification corresponds to the difference between observation with the naked
eye and observation through a magnifying device like a telescope. If a telescope configuration has a
magnification of 30x, then an object viewed through the telescope will appear 30 times larger than it
would with the naked eye. To calculate the magnification of your telescope setup, divide the focal length
of the telescope tube by the focal length of the eyepiece.
NOTE:
The magnifying power of a telescope is determined by dividing the focal length of the telescope by
the focal length of the eyepiece. This means that as the focal length of your eyepiece increases, the
magnifying power decreases.
Using Your Telescope:
After you have assembled your telescope, you are ready to start observing. Put the 20mm eyepiece
into the diagonal to get the widest field of view. This wider field of view will make it easier to locate
and track objects.
To move the scope up, down and side to side, loosen the locking screws slightly and grip the telescope
near where the tube meets the focuser and steadily move the tube until your target comes into view
in the eyepiece. Once you have found and focused on your desired target, you can lock the telescope
into position by tightening the two locating screws. It is important to remember that the rotation of the
Earth means objects will move out of your eyepiece fairly quickly.
For a closer look at an object, you can insert the 12.5mm eyepiece. The magnification will increase
from 18x to 28x.
Cleaning:
Your telescope is a precision optical device and keeping the optics free of dust and dirt is crucial for
optimal performance. To clean the lenses (objective and eyepiece) use only a photo-grade soft brush
or a lint-free cloth, like a microfiber cloth. Do not press down too hard while cleaning, as this might
