Bresser TeleMicro Set Mode D'emploi page 14

f=20 mm f=6 mm
The Moon
Orion Nebula (M 42)
Ring Nebula in Lyra constellation (M 57)
Dumbbell Nebula in the Vulpecula
(Fox) constellation (M 27)
14
Telescope ABC's
What do the following terms mean?
Zenith mirror:
A mirror that defl ects the ray of light 90 de-
grees. With a horizontal telescope tube, this
device defl ects the light upwards so that you
can comfortably observe by looking down-
wards into the eyepiece. The image in a zenith
mirror appears upright, but rotated around its
vertical axis (what is left appears right and vice
versa).
Focal width:
Everything that magnifi es an object via an op-
tic (lens) has a certain focal width. The focal
width 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 widths of the telescope
tube and the eyepieces are combined:
Lens:
The lens turns the light which 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 width).
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 magni-
fi ed still more.
There is a simple formula for calculating the
magnifi cation:
Focal width of the telescope tube / Focal
width of the eyepiece = Magnifi cation
You see: In a telescope, the magnifi cation de-
pends on both the focal width of the telescope
tube and the focal width of the eyepiece.
Magnifi cation:
The magnifi cation corresponds to the differ-
ence between observation with the naked
eye and observation through a magnifi cation
apparatus (e.g. a telescope). In this scheme,
observation with the eye is considered "sin-
gle", or 1x magnifi cation. Accordingly, if a
telescope has a magnifi cation of 30x, then
an object viewed through the telescope will
appear 30 times larger than it would with the
naked eye. See also "Eyepiece."