Meade 2080 - Focusing and Magnification; Focusing the Telescope; Understanding Magnification

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Unlock the Dec. lock (2), Fig. 1, and R.A. lock (5),
center the ~bject in the telescopic field of view, and then
re-lock the Dec. and R.A~ locks. Precise image centering is
accomplished by using the Dec. and R.A. slow motion controls,
(4 ) and (6) .
FOCUSING
The focusing knob (10), Fig. 1, is located at the "4 o'clock"
position as you face the rear cell of the telescope. Focus-
ing is accomplished internally by a precise motion of the
telescope primary mirror, so that, as you turn the focus knob
there are no externally moving parts.
Focusing the telescope from its nearest possible focus point
(on an object about 25 ft. away with the Model 2080, or
about SO ft. with the Model 2120) to an object at infinity
requires a fairly large number of rotations of the focus knob.
The focuser is designed to provide an extremely sensitive
means of bringing an object into precise, sharp focus. After
a specific object has been brought into focus, closer ob-
jects require turning the focus knob clockwise; more distant
objects require turning the focus knob counterclockwise.
It is possible that you may notice a slight shifting of
the image as you focus, particularly at high powers. This
image shift is caused by very small lateral motions of the
primary mirror as it moves toward or away from the secondary
mirror during the focusing procedure.
MAGNIFICATIONS
The magnification, or power, of the telescope depends on
two optical characteristics: the focal length of the main
telescope and the focal length of the eyepiece used during
a particular observation. The focal length of the main Model
2080 telescope is fixed at 2000mmi the focal length of the
main Model 2120 telescope is fixed at 2500mm. To calculate
the power in use with a particular eyepiece, divide the .
focal length of the eyepiece into the focal length of the
main telescope. For example, using the MA 25mm eyepiece
supplied with the Model 2080, the power is calculated as
follows:
Power = 2000mm = 80X
25mm
Similarly, with the MA 9mm eyepiece, a magnifying pow~r
of 2000mm/9mm, or 222X, results. The ~ of eyepiece
(whether "MA" Modified Achromatic, "OR" Orthoscopic, "ER"
Erfle, etc.) has no bearing on magnifying power, but does