The LX10's wide range of high-performance standard features make this telescope
an excellent observing tool for the serious amateur astronomer. The range
of observable astronomical objects is, with minor qualification, limited
only by the observer's motivation.
|IMPORTANT NOTICE! Never use a telescope or spotting scope to look at the Sun! Observing the Sun, even for the shortest fraction of a second, will cause irreversible damage to your eye as well as physical damage to the telescope or spotting scope itself. |
This section provides a basic introduction to the terminology associated
with astronomy, and includes instructions for finding, following and photographing
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Celestial Coordinates: Declination and Right Ascension
Celestial objects are mapped according to a coordinate system on the Celestial
Sphere, the imaginary sphere on which all stars appear to be placed. This
celestial object mapping system is analogous to the Earth-based coordinate
system of latitude and longitude.
The poles of the celestial coordinate system are defined as those two points
where the Earth's rotational axis, if extended to infinity, north and south,
intersect the celestial sphere (Fig. 12).
Thus, the North Celestial Pole is that point in the sky where an
extension of the Earth's axis through the North Pole intersects the celestial
sphere. This point in the sky is located near the North Star, Polaris.
In mapping the surface of the Earth, lines of longitude are drawn between
the North and South Poles. Similarly, lines of latitude are drawn in an
east-west direction, parallel to the Earth's Equator. The Celestial Equator
is a projection of the Earth's Equator onto the celestial sphere.
Just as on the surface of the Earth, in mapping the celestial sphere imaginary
lines have been drawn to form a coordinate grid. Thus, celestial object
positions on the Earth's surface are specified by their latitude and longitude.
For example, you could locate Los Angeles, California, by its latitude (34°)
and longitude (118°); similarly, you could locate the constellation
Ursa Major by its position on the celestial sphere:
R.A.: 11hr; Dec: +50°.
The celestial analog to Earth latitude is called Declination, or "Dec",
and is measured in degrees, minutes and seconds (e.g., 15° 27'
33"). Declination shown as north of the celestial equator is indicated
with a "+" sign in front of the measurement (e.g., the
Declination of the North Celestial Pole is +90°), with Declination
shown as south of the celestial equator indicated with a "-" sign
(e.g., the Declination of the South Celestial Pole is -90°)
(Fig. 12). Any point on the celestial equator
itself (which, for example, passes through the constellations Orion, Virgo
nd Aquarius) is specified as having a Declination of zero, shown as 0°
The celestial analog to Earth longitude is called "Right Ascension",
or "R.A.", and is measured in time on the 24 hour "clock"
and shown in hours ("hr"), minutes ("min") and seconds
("sec") from an arbitrarily defined "zero" line of Right
Ascension passing through the constellation Pegasus. Right Ascension coordinates
range from 0hr 0min 0sec to 23hr 59min 59sec. Thus there are 24 primary
lines of R.A., located at 15 degree intervals along the celestial equator.
Objects located further and further east of the prime Right Ascension grid
line (0hr 0min 0sec) carry increasing R.A. coordinates.
All celestial objects are specified in position by their celestial coordinates
of Right Ascension and Declination. The telescope's Dec and R.A. setting
circles (8 and 9, Fig. 1) may be dialed
to the coordinates of a specific celestial object, which may then be located
without a visual search. However, before you can make use of the telescope's
setting circles to locate celestial objects, your telescope must first be
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With the telescope polar aligned two important telescope capabilities are
enabled: (a) the motor drive permits the telescope to track any astronomical
object, automatically; (b) the telescope's setting circles, discussed
above, may be used to locate faint celestial objects directly from their
Celestial objects are essentially fixed on the celestial sphere; however,
they appear to move across the sky in an arc as the Earth rotates on its
axis, with a complete rotation of the Earth occurring once in every 24 hour
period. This apparent motion is not obvious to the unaided eye, but viewed
through a telescope such as the LX10, this motion is rapid indeed. Objects
centered in the telescope move entirely out of the field of view in 15 to
60 seconds, depending upon the magnification employed.
During the 24 hour period of the Earth's rotation, stars make one complete
revolution about the Celestial Pole, making concentric circles with the
Celestial Pole at the center. By lining up the telescope's polar axis
with the North Celestial Pole (or South Celestial Pole if you are observing
from the Earth's Southern Hemisphere), celestial objects may be followed
(tracked) by moving the telescope about one axis, the polar axis.
The following polar alignment procedure assumes that the telescope has been
set up on the Equatorial Wedge and LX10 Field Tripod, as shown in Fig.
Polar alignment consists of the following two operations:
a. Setting the telescope's latitude angle, as read on the wedge's latitude
scale (5, Fig. 4), so that the latitude scale reads the latitude of your
observing location. Use the center of the hex-head screw (4, Fig. 4)
as an indicator to read latitude angle.
CAUTION! Since the full weight of the telescope is resting on the
tilt plate of the equatorial wedge, DO NOT loosen screws (4), Fig.
4, without FIRMLY holding the telescope by its fork arms with one
hand while loosening the screws (4), Fig. 4 on each side of the wedge, with
the other hand. Alternately, enlist the assistance of a second person for
Look up the latitude of your observing location. (Most road maps show lines
of latitude.) Then, keeping the precautionary note above in mind, loosen
the screws (4), Fig. 4, on each side of the wedge, and move the telescope
in latitude angle until the hex-head screw reads the latitude of your observing
b. Rotating the telescope-and-wedge as a unit on the tripod head until
the telescope's polar axis (17), Fig. 1,
Locating due-north by using Polaris, the North Star, is adequate for the
purposes discussed here. Polaris can be found in relation to the Big Dipper
by projecting a line from the so-called "pointer stars" of the
Big Dipper, as shown in Fig. 14.
To rotate the telescope-and-wedge, loosen slightly the manual knob
(6), Fig. 4; the telescope-and-wedge may then be rotated on top of the field
tripod head. Note the telescope's polar axis, as shown in (17), Fig. 1.
Rotate the telescope-and-wedge until the telescope's polar axis points due-north;
then re-tighten the manual knob (6), Fig. 4.
With (a) and (b) accomplished the telescope is sufficiently well polar aligned
for all visual observing purposes, as well as for photography of the Moon
and planets. Long-exposure astrophotography requires more precise polar
alignment, a subject discussed in the section "Precise Polar Alignment,"
With the level of pointing accuracy obtained by the above procedure the
telescope's motor drive will accurately track and keep objects in the telescope's
field of view for perhaps 20 to 30 minutes.
Once the latitude angle of the equatorial wedge has been set you will not
need to realign the latitude angle of the equatorial wedge unless you move
to a new observing site that is a considerable distance in latitude away
from your original observing site; 70 miles of movement north or south is
equivalent to only one degree in latitude change. Removing the equatorial
wedge from the tripod will not affect the latitude setting.
After your have polar aligned your telescope for the first time, take a
moment to check the calibration of the Declination setting circles (8, Fig.
1). This is accomplished by following these steps:
1. Center Polaris in the telescope's field of view.
2. Slightly loosen the central hub of each of the Declination setting circles.
(One circle is on each fork arm.)
3. Use your finger to turn each setting circle until the dial reads 89.2°, the
Declination of Polaris; then re-tighten the central hubs of each circle
without moving the circle. The Declination setting circles are now calibrated.
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Precise Polar Alignment
Precise polar alignment is essential for long-exposure astrophotography
(typically defined as photo-exposures of 10 minutes or longer). Fewer tracking
corrections are required during the duration of the exposure when the telescope
is precisely polar aligned.
Precise polar alignment requires the use of a crosshair eyepiece, such as
the Meade Illuminated Reticle Eyepiece, and a 2x Barlow lens for increased
magnification (see Optional Accessories).
The method for precise polar alignment commonly referred to as the
"drift" method is as follows:
1. Obtain a rough polar alignment as described above. Once approximate alignment
has been accomplished, insert the 2x Barlow lens and the illuminated reticle
eyepiece into the telescope's eyepiece holder.
2. With the motor drive running, point the telescope at a moderately bright
star near where the meridian (the north-south line passing through your
local zenith) and the celestial equator intersect. For best results, the
star should be located within +/-30 minutes in R.A. of the meridian and
within +/- 5° in Dec of the celestial equator. Pointing the telescope
at a star that is straight up, and then moving the telescope in Dec to read
0° Dec, will point the telescope to the correct position.
3. Disregarding the drift in R.A., note the star's drift in Declination:
a. If the star drifts South (or down), the telescope's
polar axis is pointing too far East (Fig. 15).
4. Move the wedge in azimuth (horizontal) to change the polar alignment.
Reposition the east-west polar axis orientation until there is no further
north-south drift by the star. Track the star for a period of time to be
certain that its Declination drift has ceased.
b. If the star drifts North (or up), the telescope's polar axis is
pointing too far West (Fig. 16).
5. Next, point the telescope at another moderately bright star near the
Eastern horizon, but still near the celestial equator. For best results,
the star should be about 20° or 30° above the Eastern horizon
and within +/- 5° of the celestial equator (i.e., still at about
6. Once again, note the star's drift in Declination:
a. If the star drifts South (or down), the telescope's
polar axis is pointing too low (Fig. 17).
7. Use the fine latitude adjustment on the equatorial wedge (7, Fig.
4) to change the latitude angle based on your observations above. Again,
track the star for a period of time to verify that Declination drift has
b. If the star drifts North (or up), the telescope's polar axis is
pointing too high (Fig. 18).
After completing these procedures your telescope is precisely polar aligned,
minimizing the need for tracking corrections during long-exposure astrophotography.
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How to Locate Objects in the Night Sky
Now that your telescope is fully assembled and polar aligned, you are ready
to begin observations.
Note that although the above assembly and polar alignment procedures may
seem quite tedious, particularly if the LX10 is your first serious telescope, in
fact, assembly and approximate polar alignment (accurate enough for visual
observing) will quickly become routine. Once set, the latitude angle of
the equatorial wedge need never be changed, unless you move your observing
site a considerable distance in latitude, perhaps 150 miles or more.
For the beginning amateur astronomer, the simplest method of locating objects
in the night sky, and an excellent way to learn how to operate your
telescope, is to look at a celestial object you can clearly see with
your own eyes.
Find the desired object in the viewfinder, center the object in the viewfinder's
crosshairs, then observe through the main telescope's eyepiece and adjust
the focus knob until the image is clear and sharp. With the motor drive
turned on, observe how the telescope tracks, or follows, the object as it
arcs across the sky. Turn the motor drive off for a few seconds, and note
how rapidly the objects move through the field of view.
The position of celestial objects changes over the course of the year, so
you should obtain a star chart, such as the Meade Star Charts, available
from your Meade dealer, or refer to the monthly star chart presented
in astronomy magazines, such as Sky & Telescope and Astronomy.
With these aids and with a little experience at the controls of the LX10,
you will soon be exploring the surface of the Moon, the planets of our Solar
System and the incredible assortment of star clusters, galaxies, and nebulae
that lie beyond.
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Setting circles included with the LX10 permit the location of faint celestial
objects not easily found by direct visual observation. Located on the top
surface of the telescope's drive base, the R.A. circle (9), Fig.
1, is 8" in diameter. Declination circles (8), Fig. 1, are located
at the top of each fork tine. With the telescope pointed at the North Celestial
Pole, the Dec circle should read 90° (understood to mean +90°).
Objects located below the 0-0 line of the Dec circle carry minus Declination
coordinates. Each division of the Dec circle represents a 1° increment.
The R.A. circle runs from 0hr to (but not including) 24hr, and reads in
increments of 5min.
Note that the R.A. circle is double-indexed; i.e., there are two
series of numbers running in opposite directions around the circumference
of the R.A. circle. The outer series of numbers (increasing counterclockwise)
applies to observers located in the Earth's Northern Hemisphere; the inner
series of numbers (increasing clockwise) applies to observers located in
the Earth's Southern Hemisphere.
To use the setting circles to locate an object not easily found by direct
visual observation, please note as follows:
With the telescope aligned to the pole, center an object
of known R.A. in the telescopic field. Then turn the R.A. circle,
which can be rotated manually, until the R.A. coordinate of the object is
correctly indicated by the R.A. pointer. As long as the telescope's motor
drive remains "ON," the R.A. pointer will then correctly indicate
the R.A. of any object at which the telescope is pointed throughout the
duration of the observing session.
To locate a particular object, first look up the celestial coordinates (R.A.
and Dec.) of the object in a star atlas. Then loosen the R.A. lock and turn
the telescope to read the correct R.A. of the desired object; lock the R.A.
lock onto the object. Next, turn the telescope in Declination to read the
correct Declination of the object. If the procedure has been followed carefully,
and if the telescope was well-aligned with the pole, the desired object
should now be in the telescopic field of a low-power eyepiece.
If you do not immediately see the object you are seeking, try searching
the adjacent sky area, using the R.A. and Dec. slow-motion controls to scan
the surrounding region. Keep in mind that, with the 25mm eyepiece, the field
of view of the LX10 is about 0.5°. Because of its much wider field,
the viewfinder may be of significant assistance in locating and centering
objects, after the setting circles have been used to locate the approximate
position of the object.
Pinpoint application of the setting circles requires that the telescope
be precisely aligned with the pole. Refer to the preceding section on "Precise
Polar Alignment" for further details.
The setting circles may also be utilized in the absence of a power source
for the motor drive. In this case, however, it is necessary to manually
reset to the R.A. of the object you are observing just before going to the
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To enjoy your LX10 to the fullest, follow these recommendations:
1. Always let the telescope "cool down" to the outside temperature
before attempting to make serious observations. After moving the telescope
from a warm house, the telescope's optics need about 15 to 20 minutes to
adjust to the outside temperature before they will perform well.
2. Avoid setting up the telescope inside a room and observing through an
open window (or worse, a closed window!). In such a case air currents caused
by differences in indoor/outdoor temperatures make quality astronomical
optical performance impossible.
Note: A practical exception to this rule is the case where your telescope
is set up in a living room or den for observing an outdoor terrestrial scene
or view through a closed window. At low powers (up to about 60X) the telescope
will perform reasonably well in this application, but the observer should
understand that the optical performance under these conditions cannot approach
the performance that will be realized if the telescope were instead set
3. As discussed in "Magnifications" (Part
2), avoid "overpowering" your telescope. If the astronomical
or terrestrial image becomes fuzzy at high powers, drop down to a lower
power. Image degradation at high powers is not due to any fault of the telescope
but is caused by heat waves and turbulence in the Earth's atmosphere. Astronomical
observations at high powers (above 200X) should be undertaken only when
the atmosphere is very steady, as confirmed by an absence of "twinkling"
in star images.
4. Try not to touch the eyepiece when observing through the telescope. Vibrations
in your hand are immediately transferred to the telescopic image.
5. If you wear eyeglasses and do not suffer from astigmatism, take your
glasses off when using the telescope; the telescope's magnification compensates
for near- or far-sightedness. Observers with astigmatism should, however,
wear their glasses, since the telescope cannot compensate for this eye defect.
6. Allow your eyes to become "dark adapted" before attempting
serious astronomical observations through the telescope. Night adaptation
normally requires about 10 to 15 minutes.
7. As you use your LX10 more and more for astronomical observing, you will
find that you are seeing finer and finer detail on the surface of Jupiter,
for example. Observing through a fine optical instrument is to some degree
an acquired skill. Celestial observing becomes increasingly rewarding as
your eye becomes better trained in the detection of subtle variations of
color, contrast, and resolution.
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Using the LX10 for Astrophotography
As discussed earlier, the LX10 is well suited for the astrophotographer,
facilitating both long-exposure guided photography or CCD imaging with its
stable fork mounting, DC electronic worm-gear drive system, and hand controller.
Astrophotography of the Moon and planets with a 35mm SLR camera requires
the optional #62 T-Adapter (Fig. 19).
Long-exposure, deep-space astrophotography of more than about 5 or 10 minutes'
duration requires two telescope capabilities: (a) a means of monitoring
the precise position of the object being photographed throughout the exposure,
and (b) a means of changing the telescope's position very slightly to keep
the object in exactly the same position throughout the exposure.
The Meade Off-Axis Guider and Illuminated Reticle Eyepiece, optional accessories
fully described in the Meade General Catalog, fulfill the first requirement
above. The LX10's standard-equipment hand controller, when equipped with
the optional LX10 Electric Declination Motor, satisfies the second requirement.
With the Electric Declination Motor attached, all four correction pushbuttons
of the hand controller (N-S-E-W) are actuated, for precise dual-axis corrections
during long-exposure astrophotography.
A few tips for basic astrophotography with the LX10:
1. The LX10 must be precisely polar aligned, as discussed above.
2. The tripod must be on a solid surface and the base of the equatorial
wedge must be level.
3. Always use a cable-operated shutter release. Using the shutter release
on the camera body may cause the camera to vibrate and blur your photograph.
4. Focus the image with extreme care. While observing the celestial object
through the camera's viewfinder, turn the LX10's focus knob to achieve the
sharpest possible focus, then open the camera's shutter to begin your exposure.
5. For terrestrial photography with the LX10, be aware that long distance
photography is best accomplished in the early morning hours before heat
waves begin to rise from the Earth's surface, and distort your photograph.
6. Astrophotography is an acquired skill; exercise patience and expect to
waste a few rolls of film as you learn the techniques. The rewards of taking
a quality astrophotograph, however, will make all your efforts worthwhile.
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Although principally designed for astronomical observing, the LX10 makes
an excellent terrestrial observing tool.
The telescope's controls are utilized in the same manner as for astronomical
applications, but there are several significant differences in how you will
locate and observe terrestrial subjects.
The LX10's viewfinder presents an inverted image; what you see appears upside-down
and reversed left-for-right.
With the standard-equipment diagonal prism and 25mm eyepiece in place in
the main telescope, terrestrial images will appear right-side-up, but reversed
left-for-right. This orientation is usually acceptable for terrestrial observing,
except in the case of reading a distant sign or automobile license plate,
Terrestrial image orientation can be fully corrected with the optional Meade
#928 45° Erect-Image Diagonal Prism (see Optional