General Maintenance; Inspecting The Optics - Meade LX70 Series Instruction Manual

Maintenance

General Maintenance

LX70-Series telescopes are precision optical
instruments designed to yield a lifetime of re-
warding views. Given the care and respect due
any precision instrument, your LX70 will rarely,
if ever, require factory servicing. Maintenance
guidelines include:
a. Avoid cleaning the telescope's optics: A little
dust on the mirrors or the front surface of the
telescope's lens causes virtually no degrada-
tion of image quality and should not be consid-
ered reason to clean the lens.
b. When absolutely necessary, dust on the mir-
rors or front lens should be removed with gentle
strokes of a camel hair brush or blown off with
an ear syringe (available at any pharmacy).
DO NOT use a commercial photographic lens
cleaner.
c. Organic materials (e.g., fingerprints) on the
front lens may be removed with a solution of
3 parts distilled water to 1 part isopropyl alco-
hol. You may also add 1 drop of biodegrad-
able dishwashing soap per pint of solution. Use
soft, white facial tissues and make short, gentle
strokes. Change tissues often. Caution: Do not
use scented or lotion tissues or damage could
result to the optics.
d. If the LX70 is used outdoors on a humid
night, water condensation on the telescope sur-
faces will probably result. While such conden-
sation does not normally cause any damage to
the telescope, it is recommended that the entire
telescope be wiped down with a dry cloth before
the telescope is packed away. Do not, however,
wipe any of the optical surfaces. Rather, simply
allow the telescope to sit for some time in the
warm indoor air, so that the wet optical surfaces
can dry unattended.

Inspecting the Optics

A Note about the Flashlight Test: If a flashlight or
other high-intensity light source is pointed down
the main telescope tube, the view (depending
upon the observer's line of sight and the angle
of the light) may reveal what appears to be
scratches, dark or bright spots, or just generally
uneven coatings, giving the appearance of poor
quality optics. These items are only seen when
a high intensity light is transmitted through lens-
es or reflected off the mirrors, and can be seen
on any high quality optical system, including gi-
ant research telescopes. The optical quality of
a telescope cannot be judged by the "flashlight
test;" the true test of optical quality can only be
conducted through careful star testing.
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Figure 33: Correct (1) and incorrect (2) collimation as viewed
during a star test
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