47
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 effects are only
seen when a high intensity light is transmitted through lenses or reflected off the mirrors, and
can be seen on any high quality optical system, including giant 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.
Gauging the Movement of the Telescope
A common complaint of many first-time telescope owners is that they cannot see the telescope
“move” when the motor drive is engaged. If fact, when the batteries are installed, the power is
on and the R.A. lock engaged, the telescope is moving. However, the movement is at the same
speed as the hour hand of a 24-hour clock; as such, the movement is difficult to discern
visually.
To check the movement of your telescope, look at an astronomical object through the
telescope’s eyepiece with the telescope polar aligned and with the motor drive on. If the object
remains stationary in the field of view, your telescope is operating properly. If not, check to
ensure that you have engaged the R.A. lock and that the power switch on the control panel is
on. Also check if "Astronomical" is selected in the "Targets" option of the setup menu.
Meade Consumer Solutions Service
If you have a question concerning your LX90 telescope, call the Meade Instruments Customer
Solutions Department at (800) 626-3233. Consumer Solutions hours are 8:00 AM to 5:00 PM,
Pacific Time, Monday through Friday. In the unlikely event that the LX90 requires factory
servicing or repairs,
write or call the Meade Consumer Solutions Department first, before
returning the telescope to the factory, giving full particulars as to the nature of the problem, as
well as your name, address and daytime telephone number. The great majority of servicing
issues can be resolved by telephone, avoiding return of the telescope to the factory.
Fig. 26: R.A. Lock.
Fig. 27: Dec Lock.
Look into the Future
The Date option in the Setup menu is much more than just an entry of today's
date; with it you can look far into the future or learn about past events. AutoStar
can calculate the date and times of future events and, except for eclipses, past
events as well (based on the current calendar system).
E.g., a Sunrise on
March 6, 2043 A.D. or the Vernal Equinox in 1776 A.D. To use this feature,
enter the desired date in the Setup menu or select an option in the Event menu.
AutoStar, using the Event menu, can calculate dates and times for Sunrises,
Sunsets, Moonrises, Moonsets, Moonphases, Solar and Lunar Eclipses (for
the next 100 years), meteor showers, equinoxes and solstices and the mini-
mums of Algol.
One very practical use of the Event menu is to check the Sunset option to
determine when you can begin your astronomical observing session.
LX90 TIPS
Dec
Looking at or near the
Sun
will cause
irreversable
damage to your eye. Do not point this telescope at or near the
Sun. Do not look through the telescope as it is moving.
