Filter
Top Products
– 10 –
The number of fascinating objects visible through your Infinity refractor is limited only by your own
motivation. Astronomical software, or a good star atlas (see “Meade Star Charts” in OPTIONAL
ACCESSORIES, page 11) will assist you in locating many interesting celestial objects. These objects
include:
• Cloud belts across the surface of the planet Jupiter.
• The 4 major satellites of Jupiter, visible in revolution about the planet, with the satellite positions
changing each night.
• Saturn and its famous ring system, as well as several satellites of Saturn, much fainter than the major
satellites of Jupiter.
• The Moon: A veritable treasury of craters, mountain ranges and fault lines. The best contrast for viewing
the Moon is during its crescent phase. The contrast during the full Moon phase is low due to the angle
of illumination.
• Deep-Space: Nebulae, galaxies, multiple star systems, star clusters—hundreds of such objects can be
located through the Polaris 60EQ-D.
• Terrestrial Objects: Your Polaris refractor may also be used for the observation of land subjects. In this
case, note that the diagonal mirror results in an image which is reversed left-for-right, but which is
correctly oriented up-and-down. For a fully corrected image, the #927 Erect Image Prism system is
required. (See “OPTIONAL ACCESSORIES”). Terrestrial observations should almost always be made
using a low power eyepiece for bright, sharp images. Land objects will not normally accept higher
powers because the telescope is being used through the thickest part of the Earth’s atmosphere, unlike
astronomical observations made by pointing the telescope up through the atmosphere.
CALCULATING POWER
The power, or magnification, at which a telescope is operating is determined by 2 factors: the optical, or
focal, length of the telescope’s objective lens and the focal length of the eyepiece. The focal length of the
Polaris 60EQ-D is 900mm. To compute power, divide the focal length of the eyepiece into the focal length
of the objective lens. The resulting quotient is the magnifying power of the telescope when used with the
eyepiece in question. For example, the 25mm eyepiece yields, with the Polaris 60EQ-D, a power of:
Power = 900mm ÷ 25mm = 36X
The letter “H” refers to the “Huygens” optical design which yields well corrected images with refracting
telescopes. The optical design of the eyepiece has no bearing on power, however.
The Barlow lens serves to increase the power of each eyepiece. Insert the 3X Barlow lens into the telescope
focuser first, followed by the diagonal prism and eyepiece, secure by tightening the respective thumbscrews.
For example, the 25mm (36X) eyepiece, when used in conjunction with the 3X Barlow Lens, yields 108X.
A few words of wisdom about power. While the theoretical power or magnification of a telescope is
virtually limitless, there are, however, practical limits imposed by the Earth’s atmosphere as to what can be
seen well at a given power. The most often useful higher magnification with any 60mm diameter telescope
is in the range of 80 to 120 power. The general rule to follow with any telescope, regarding power: only use
as much magnification as supports a steady, well-defined image. This often varies with the stability of the air
being viewed through and is one reason why having various eyepieces is highly desirable. Higher powers
are no guaranty of better images; in fact, the opposite is often true. Also, keep in mind, that land viewing
and wide-field, deep-space observation are, generally, low power applications of your telescope.
MAINTENANCE
As with any quality optical instrument, lens surfaces should be cleaned as infrequently as possible. A little
dust on the surface of the objective (front) lens causes negligible degradation of image quality and should
not be considered reason to “clean” the lens. When lens cleaning does become necessary, use a camel’s
hair brush or compressed air blown gently to remove dust. Wipe only with a soft, clean cloth, applying as
little pressure as possible to avoid scratching glass surfaces. Note: remove the dew shield/lens shade (29)
to access the objective lens (22) for cleaning.