Meade 2045 User manual

OPERATING INSTRUCTIONS
Meade Instruments Corporation
1675 Toronto Way, Costa Mesa, California 92626 U.S.A.
[phone]
MEADE MODEL 2045
4" SCHMIDT-CASSEGRAIN TELESCOPE

TABLE OF CONTENTS
Introduction
Standard Equipment
Setting Up The Telescope
Telescope Operation: Your First Observations
Focusing
Magnification
The Viewfinder
Celestial Coordinates
Lining Up With The Celestial Pole
Latitude Ranges
High Latitudes
Low Latitude Balance Weight
Precise Polar Alignment
Electronic Motor Drive
Setting Circles
Observing with the Telescope
Telescope Maintenance
Basic Specifications: Model 2045

MEADE MODEL 2045:4" SCHMIDT-CASSEGRAIN TELESCOPE
INTRODUCTION
The Meade Model 2045 permits a very wide range of serious astronomical and terrestrial applications —
and in an extremely compact and portable optical/mechanical package. The advanced
Schmidt-Cassegrain mirror-lens ("catadioptric") optical design of the Model 2045 enables a 40” effective
optical tube length to be compressed into an actual tube length only 10" long — and with no sacrifice
whatsoever in the most demanding performance requirements. The capabilities of the instrument are
essentially limited not only by the telescope, but by the acquired skills of the observer and photographer.
Do take time to read this manual thoroughly so that you will be fully acquainted with the many important
features of the telescope, as well as with the auxiliary equipment and accessories available for advanced
applications.
STANDARD EQUIPMENT
• 4” Schmidt-Cassegrain optical tube assembly and fork mount with pulse motor drive system
• 1 Eyepiece — MA25mm 1-1/4" O.D.
• 1 eyepiece holder/diagonal prism assembly
• 5x24mm viewfinder
• 3 thread-in tripod legs (2 fixed length legs; 1 adjustable length leg)
• Dust covers (front and rear)
• Battery pack with cord
• Hardware package
SETTING UP THE TELESCOPE
The basic Model 2045 telescope is shipped as a completely assembled instrument. After removing he
telescope from its shipping carton and carrying case, familiarize yourself with the various controls and
accessories (See Fig. 1).
The eyepiece holder/diagonal prism threads directly onto the rear cell thread of the telescope and, in turn,
accepts the supplied eyepiece. The 5x24 viewfinder attaches to the rear portion of the telescope with the
supplied hardware (see (1), Fig. 1).
For astronomical observations, the diagonal prism provides a comfortable right-angle viewing position.
Note, however, that although the image appears correctly oriented up-and-down, it is reversed
left-for-right. For terrestrial observations, where a fully-corrected image orientation (both up-and-down
and left-for-right) is desirable, the optional #928 45* Erect-Image Roof Prism and eye piece holder (1-1/4")
should be ordered separately. The standard diagonal prism is also well-suited for many terrestrial
observations. Eyepieces are held in place in the diagonal prism with a moderate tightening of the small
thumbscrew.

Fig. 1 — Meade Model 2045
(1) Viewfinder
(2) Declination Lock
(3) Declination Setting Circle
(4) Motor Drive Base
(5) Declination Slow-Motion Control
(6) Adjustable Tripod Leg
(7) Right Ascension Lock
(8) Right Ascension Setting Circle
(9) R.A. Slow-Motion Control
(10) Tube Adapter
(11) Eyepiece-Holder/Diagonal Prism
(12) Eyepiece
(13) Fixed-Length Tripod Leg
(14) Tripod Adapter (Optional)

TELESCOPE OPERATION: YOUR FIRST OBSERVATIONS
With the telescope standing upright on its drive base (i.e. without the 3 tripod legs attached), the
eyepiece-holder/diagonal prism attached, and with the MA 25mm eyepiece inserted into the diagonal
prism, you are ready to make observations through the telescope.
WARNING ! NEVER POINT THE TELESCOPE DIRECTLY AT OR NEAR THE SUN, OR ATTEMPT TO
OBSERVE THE SUN, EITHER THROUGH THE MAIN TELESCOPE OR THE VIEWFINDER, WITHOUT
A PROPER PROFESSIONAL QUALITY SOLAR FILTER! INSTANT AND IRREVERSIBLE INJURY TO
YOUR EYE MAY OTHERWISE RESULT!
By unlocking the R.A. lock (7), Fig. 1, the telecope may be turned rapidly through wide angles in Right
Ascension (R.A.) The reason for the terminology "Right Ascension" and its complementary term
"Declination" will be made clear further on in this manual. For now, "Right Ascension" simply means
"horizontal" and "Declination" means "vertical."
DO NOT ATTEMPT TO MOVE THE TELESCOPE MANUALLY IN A HORIZONTAL DIRECTION WHEN
THE R.A. LOCK IS IN THE FULLY "LOCKED" POSITION, AS SUCH OPERATION MAY RESULT IN
DAMAGE TO THE INTERNAL GEAR SYSTEM.
Release the Declination lock (2), Fig. 1, by rotating the control lever in a counterclockwise direction. This
permits sweeping the telescope through wide angles in Declination.
DO NOT ATTEMPT TO MOVE THE TELESCOPE MANUALLY IN A VERTICAL DIRECTION WHEN
THE DECLINATION LOCK IS IN THE "LOCKED" POSITION.
To use the Declination fine-adjust, or slow-motion control, lock the telescope in Declination using the
Declination lock (2) Fig. 1, and turn the Declination slow-motion knob (5), Fig. 1.
NOTE THAT THIS DECLINATION SLOW-MOTION CONTROL HAS A FIXED TRAVEL LENGTH,
LIMITED BY THE MOTION OF A TANGENT ARM (LOCATED INSIDE THE FORK TINE). DO NOT
FORCE THE DECLINATION SLOW-MOTION KNOB WHEN THE TANGENT ARM HAS REACHED THE
END OF ITS TRAVEL. IN THIS CASE, TURN THE DEC. KNOB TO RETURN THE TANGENT ARM TO
THE MID POINT IN ITS TRAVEL RANGE, UNLOCK THE DECLINATION LOCK AND RE-CENTER THE
TELESCOPE MANUALLY.
With the above mechanical operations in mind, select an easy-to-find terrestrial object as your first subject
— for example a house or building perhaps one-half mile distant. Unlock the Dec. lock (2), Fig. 1, and
R.A. lock (7), Fig. 1, center the object 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 (5) and
(9), Fig. 1.
FOCUSING
The focusing kob is located at the "4 o’clock" position as you face the rear cell of the telescope. Focusing
is accomplsihed 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 15 ft. away) 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 objects require turning the focus knob clockwise; more distant objects
require turning the focus knob counterclockwise.
It is possible that you may notice a very 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.
MAGNIFICATION
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 Model 2045 telescope is fixed at 1000mm. 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 2045, the power is calculated as follows:
Power = 1000mm + 25mm = 40X
Similarly, with an MA 9mm eyepiece, a magnifying power of 1000mm/9mm, or 111X, results. The type of
eyepiece (whether "MA” Modified Achromatic, "OR" Orthoscopic, "SP" Super Plossl, etc.) has no bearing
on magnifying power but does affect such optical characteristics as field of view, flatness of field and color
correction.
When beginning observations on a particular object, start with a low-power eyepiece. Get the object well
centered in the field of view and sharply focused. Then try the next step up in magnification. If the image
starts to become fuzzy as you work into higher magnifications, then back down to a lower power. The
atmospheric steadiness is not sufficient to support high powers at the time you are observing. Keep in
mind that a bright, clearly resolved but small image will show far more detail than a dimmer, poorly
resolved larger image.
Optional eyepieces and the #126 2X Telenegative Amplifier are available for higher and lower powers
through the telescope.
THE VIEWFINDER
The 5x24mm viewfinder has been prefocused at infinity. Should this focusing need adjustment for your
eye, loosen the knurled collar at the objective lens end of the viewfinder (the end opposite where you
observe through the finder), enabling rotation of the objective lens cell, forward or backward for precise
focusing. Tighten down the knurled collar against the objective lens cell to lock the focus in place. Note
that no focusing is possible or necessary at the eyepiece end of the finder scope. The viewfinder will
require alignment, or collimation, to the main telescope. Using the supplied 25mm eyepiece, point the
main telescope at some easy to find land object (e.g. the top of a telephone pole or corner of a building)
at least 200 yards distant. Center a well-defined object in the main telescope. Then, using one of the hex
wrenches provided, tighten or loosen, as appropriate, the 3 collimation screws located on the finder’s rear
bracket ring until the cross hairs of the finder are precisely centered in the main telescope. With this
collimation accomplished, objects located first in the wide-field viewfinder will then be centered in the
main telescope’s field of view. Note that images seen in the viewfinder are upside-down from their
counterparts viewed through the main telescope with diagonal prism.
CELESTIAL COORDINATES
For terrestrial observing, setting the Model 2045 flat on the bottom of its drive base is a completely
satisfactory method for tracking or observing objects in the telescope. For astronomical observing,
however, the situation is quite different: objects move fairly rapidly through the field of view (due to
Earth’s axial rotation) and they move at an angle to the horizon, depending on the observer’s latitude. It
is for these reasons that the Model 2045 is equipped with two highly convenient features: a means of
tilting the entire telescope to an angle (thereby facilitating astronomical tracking); and an electronic pulse
motor drive for automatic tracking. Before discussing these points, some background in celestial
coordinates is required.
Analogous to the Earth-based coordinate system of latitude and longitude, celestial objects are mapped
according to a coordinate system on the "celestial sphere," the imaginary sphere on which all stars

appear to be placed.
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. 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. In fact, this point in the sky is located near the North Star, Polaris.
On 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 simply a projection of the Earth’s equator onto the celestial sphere. Just as on the surface of
the Earth, imaginary lines have been drawn on the celestial sphere to form a coordinate grid. Celestial
object positions are mapped on this grid in the same manner as positions on the Earth’s surface are
specified by their latitude and longitude.
The celestial equivalent to Earth latitude is called "Declination,” or simply "Dec.," and is measured in
degrees, minutes and seconds North ("+") or South of the celestial equator. Thus any point on the
celestial equator (which passes, for example, through the constellations Orion, Virgo and Aquarius) is
specified as having 0°0 min 0 sec Declination. The Declination of the star Polaris, located very near the
North Celestial Pole, is +89.2°.
The celestial equivalent to Earth longitude is called "Right Ascension," or "R.A.," and is measured in
hours, minutes and seconds from an arbitrarily defined "zero" line of R.A. passing through the
constellation Pegasus. Right Ascension coordinates range from o hr o m i n O sec up to (but not including)
24 hr o m i n o sec . Thus there are 24 primary lines of R.A., located at 15° intervals along the celestial equator.
Objects located further and further East of the prime (o hr o m , n O sec ) Right Ascension grid line carry
increasing R.A. coordinates.
With all celestial objects therefore capable of being specified in position by their celestial coordinates of
Right Ascension and Declination, the task of finding objects (in particular faint objects) in the telescope is
greatly simplified. The setting circles of the Modei 2045 may be dialed, in effect, to read the
object-coordinates, and the object found without resorting to visual location techniques. However, these
setting circles may be used to advantage only if the telescope is first properly aligned with the North
Celestial Pole.
LINING UP WITH THE CELESTIAL POLE
Objects in the sky appear to revolve around the celestial pole. (Actually, celestial objects are essentially
"fixed," and their apparent motion is caused by the Earth’s axial rotation). During any 24-hour period,
stars make one complete revolution about the Pole, describing concentric circles with the Pole at the
center. By lining up with the telescope’s polar axis with the North Celestial Pole (or, for observers located
in the Earth’s Southern Hemisphere, with the South Celestial Pole), astronomical objects may be
followed, or tracked, simply by moving the telescope about one axis, the polar axis. In the case of the
Meade Model 2045, this tracking may be accomplished automatically with the electric motor drive.
For the purposes of casual visual telescopic observations, lining up the telescope’s polar axis to within a
degree or two of the Pole is more than sufficient. With this level of pointing accuracy, the telescope’s
motor drive will track accurately and keep objects in the telescopic field of view for perhaps 20 to 30
minutes.
To line up the telescope with the North Celestial Pole, follow this procedure:
1. Attach the 3 tripod legs to the telescope, as shown in Fig. 1. Note that one leg is adjustable in length.
This leg should be threaded into the central hole on the underside of the drive base.
2. The polar axis of the telescope is an imaginary line running through the adjustable tripod leg, up through
the center of the drive base, and up between and parallel to the two fork arms. The long arrow in Fig. 2
indicates the polar axis. (It is around this axis that the telescope turns in Right Ascension). In Fig. 2, the
telescope is oriented so that the main optical tube is also aligned with the polar axis. With the telescope
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position as in Fig. 2 (careful eye alignment to make the main tube parallel to the fork arms is sufficient),
perform these two operations:
a. Turn the entire telescope on its tripod until the telescope tube is pointing due North.
b. Lengthen or shorten the adjustable tripod leg (6), Fig. 1, until the angle it makes with the horizontal
is equal to your latitude. (Most road maps show latitude). Use a protractor for this operation: hold the
protractor up to the tripod leg and adjust the leg length until the leg angle to the horizontal equals your
latitude.
In Fig. 2, note that the telescope is pointing North and the adjustable tripod leg has been set to make the
correct latitude angle with the horizontal as described in steps (a) and (b). The adjustable leg is locked to
the correct length by tightening the small thumbscrew located at the lower end of the leg.
The above procedure is approximate, but is more than adequate for visual observations through the
telescope and for many astrophotographic applications.
If the polar alignment procedure has been properly performed, then the North Star (Polaris) will be visible
in the field of view of the viewfinder, with the telescope again oriented as shown in Fig. 2. In summary, the
polar axis is indicated by the long arrow lined up with the adjustable tripod leg. This axis should (a) point
North; (b> make an angle with the tabletop (horizontal) equal to your latitude. To accomplish (b), lengthen
or shorten the adjustable tripod leg
Figure 2: Lining Up With The Pole
With the telescope thus aligned to the Pole, the position of the tripod remains fixed during all subsequent
observations through the telescope. Loosen the R.A. and Dec. locks each time you wish to move the
telescope manually to locate a new object, then re-tighten these locks once the object is in the telescopic
field of view. When the electronic pulse motor drive is plugged in, the telescope automatically tracks
astronomical objects each time you re-tighten the R.A. lock.
As a separate procedure, during your first use of the telescope, you should check the calibration of the
Declination setting circles (see (3), Fig. 1), located at the top of the two fork arms. With Polaris in the field
of the viewfinder or in the field of the main telescope if properly polar aligned, loosen slightly the knurled
central hubs of both Declination setting circles. Now turn each circle until each reads 89.2‘, the
Declination of Polaris, and then tighten down the knurled knob, avoiding any motion of the circle.
Once the correct length of the adjustable tripod length for proper polar alignment has been
determined,make a small mark on the tripod leg indicating the proper leg extension position. The tripod
leg may now be extended to the correct position without resorting to the entire procedure above. Simply
point the polar axis due North and extend the tripod leg to the pre-marked location. If you move your
observing location significantly, you will need to re-set the tripod to the correct angle. (Approximately 70
miles movement in North-South observing position is equivalent to 1* in latitude change.)

LATITUDE RANGES
Note that the adjustable leg may be varied in length to accommodate a wide range-of observing location
latitudes. In addition, this tripod leg may be threaded into any one of three holes on the underside of the
drive base to achieve an even wider range of latitude angles.
If the adjustable tripod leg is threaded into the top mounting hole (on the underside of the drive base),
then the adjustable leg covers a latitude range of from 32’ to 49"; in the middle (central) hole, it covers a
range from 27’ to 42"; and in the bottom hole, it covers a range from 21 ’ to 34".
HIGH LATITUDES
At high latitudes, the standard equipment adjustable tripod leg may not permit a sufficiently high angle for
the polar axis to be in correct alignment. In this case (at latitudes higher than about 49") the optional
"Center Tripod Leg for High Latitudes" (47’ to 69°) should be used. The high latitude adjustable leg can
be used for latitudes from 47' to 69’ as follows: with the leg in the top mounting hole, the latitude range is
60° to 69’; in the middle (central) hole, the range is from 53’ to 64°; and in the bottom hole, the range is
from 47" to 56°.
LOW LATITUDE BALANCE WEIGHT
When the Model 2045 is used at low latitudes, the telescope is tilted to a large angle. At such an angle,
the telescope may become unstable and the adjustable tripod leg may tend to lift off of the tabletop. To
prevent this instability at lower latitudes, the optional Low Latitude Balance Weight is available.
Unthread the adjustable tripod leg from its position in the drive base and slide the Low Latitude Balance
Weight onto the tripod leg. This balance weight should be placed on the adjustable tripod leg as close to
the lower (rubber tip) end of the leg as possible. After positioning the balance weight, fix it in position by a
moderate tightening of its thumb screw.
The Low Latitude Balance Weight is recommended whenever the observing location is at 30’ latitude or
lowertor visual observations or when the telescope is being used with a camera attached, at observing
latitudes of 35 * or lower.
PRECISE POLAR ALIGNMENT
Unless you intend to engage in long exposure astrophotography, it is not necessary to follow the precise
polar alignment procedure described in this section.
Notwithstanding the precision and sophistication of the quartz time base drive system supplied with the
Meade Model 2045, the fewer tracking corrections required during the course of a long-exposure
photograph, the better. (For our purposes, "long-exposure" means any photograph of about 10 minutes
duration or longer). In particular, the number of Declination corrections required is a direct function of the
precision of polar alignment.
The procedure described here should be implemented only after the alignment procedures of the
preceding section have first been carried out.
Precise polar alignment requires the use of a cross hair eyepiece. The Meade MA 12mm Illuminated
Reticle Eyepiece is well-suited in this application, but you will want to increase the effective magnification
through the use of the #126 2X Telenegative Amplifier. Then follow this procedure:
1. Place the illuminated reticle eyepiece (or eyepiece/Telengegative Amplifier combination) into the
diagonal prism of the telescope.
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2. Point the telescope with the motor drive running, 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’ of the celestial equator.
3. Note the extent of the star’s drift in Declination (disregard drift in Right Ascension):
a. If the star drifts South , the telescope’s polar axis is pointing too far East.
b. If the star drifts North, the telescope’s polar axis is pointing too far West.
4. Carefully move the table tripod of the Model 2045 to effect the appropriate change in polar alignment.
Reposition the telescope’s 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.
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.
6. Again note the extent of the star’s drift in Declination:
a. If the star drifts South, the telescope’s polar axis is pointing too low.
b. If the star drifts North , the telescope’s polar axis is pointing too high .
7. Change the extension length of the adjustable tripod leg to effect the appropriate corrections in
latitude angle. Again track the star for a period of time to be certain that Declination drift has ceased.
The above procedure results in very accurate polar alignment, and minimizes the need for tracking
corrections during astrophotography.
The optional Meade Equatorial Wedge/Field tripod system provides an extremely stable platform for the
most discriminating long exposure photography and also permits standing observations through the
telescope in the equatorial mode.
ELECTRONIC MOTOR DRIVE
Supplied as standard equipment with the Model 2045 is an extremely accurate drive gear drive system,
driven by a precision pulse motor. The power cord from the battery pack plugs into the bottom of the
telescope’s drive base. The North-South switch, located on the bottom plate of the drive base (see (4),
Fig. 1), reverses the motor drive direction, thus permitting use of the telescope in both the Northern and
Southern hemispheres.
With the telescope set up in the equatorial mode (as described above under "Lining Up with the Pole"),
plug the power cord into the drive base. Immediately, if you put your ear to the drive base of the
telescope, you will be able to hear the low level noise created by the running motor. The drive system
turns the fork mount of the telescope through one complete revolution every 24 hours, and results in the
stars "standing still" as you view them through the telescope eyepiece. The motor drive also drives the
R.A. setting circle, (see (8) Fig. 1), as described in the next section.
The motion of the telescope caused by the drive system is not obvious if you look at the telescope (in fact,
it is not even perceptible). However, while observing through the telescope, it is a very significant motion
indeed. To check this point, with a star centered in the telescope field and the electric motor drive
running, unplug the power cord: the star will immediately begin to drift out of the field of view; at higher
powers, the effect is even more pronounced.
The motor drive is engaged by turning the R.A. lock (see (7), Fig. 1) to the locked position. Simply
"unlock" the R.A. lock to disengage the motor drive when manually pointing the telescope at another
object.
in

NOTE: DO NOT ATTEMPT TO TURN THE R.A. SLOW-MOTION CONTROL KNOB WHEN THE R.A.
LOCK IS IN THE "LOCKED" POSITION. SUCH AN OPERATION WILL CAUSE INTERNAL DAMAGE
TO THE GEARS OF THE R.A. SLOW-MOTION CONTROL. IN ADDITION, DO NOT ATTEMPT TO
TURN THE TELESCOPE MANUALLY ON ITS FORK MOUNT IN R.A. WHEN THE R.A. LOCK IS
"LOCKED," AS SUCH OPERATION WILL CAUSE RAPID WEAR OF THE INTERNAL CLUTCH
SYSTEM.
SETTING CIRCLES
Setting circles included with the Model 2045 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 (7),
Fig. 1, is 6" (15cm) in diameter. The Declination circles (see (3), Fig. 1), are located on 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 Declination circle represents a 1 * increment. The R.A. circle runs from 0 hr to (but not
including) 24 hr , and reads in increments of 5 m i n .
Note that the R.A. circle of the Model 2045 is double-indexed: the upper line of numbers (running
clockwise from 0 to 23) should be used by observers in the Earth’s Southern Hemisphere (e.g. Australia):
the lower line of numbers (running counterclockwise from 0 to 23) should be used by observers in the
Earth’s Northern Hemisphere (e.g. the U.S.A.).
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 by moderate thumb pressure, 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 use the circles to locate a particular object, first look up the celestial coordinates (R.A. and Dec.) of the
object in a star atlas. Then bosen 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
was well-aligned with the pole, the desired object should now be in the telescopic field of a bw-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 Model 2045 is about 1 ’. Because of its much wider field, the 5x24mm
viewfinder may be of signifbant 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.
OBSERVING WITH THE TELESCOPE
The Meade Model 2045 4" Schmidt-Cassegrain telescope permits an extremely wide array of serbus
observational opportunities. Even in normal city conditions, with all of the related air and light polutbn,
there are many interesting celestial objects to observe. But to be sure, there is no substitute for the clear,
steady dark skies generally found away from urban environments or on mountaintops. Objects prevbusly
viewed only in the city take on added detail, are seen in wider extensbn, or fainter objects become visible
for the first time.
The amateur astronomer is faced with two broadly defined problems when viewing astronombal objects
through the Earth’s atmosphere: first is the clarity, or transparency of the air, and second, the
steadiness of the air. This latter characteristb is often referred to as the quality of "seeing." Amateur

astronomers talk almost constantly about the "seeing conditions," since, ironically, even the clearest,
darkest skies may be almost worthless for serious observations if the air is not steady. This steadiness of
the atmosphere is most readily gauged by observing the "twinkling" of the stars: rapid twinkling implies
air motion in the Earth’s atmosphere, and under these conditions, resolution of fine detail (on the surface
of Jupiter, for example) will generally be limited. When the air is steady, stars appear to the naked eye as
untwinkling points of unchanging brightness, and it is in such a situation that the full potential of the
telescope may be realized: higher powers may be used to advantage, closer double stars resolved as
distinct points and fine detail observed on the Moon and planets.
Several basic guidelines should be followed for best results in using your telescope:
1. Try not to touch the eyepiece while observing. Any vibrations resulting from such contact will
immediately cause the image to move.
2. Allow your eyes to become "dark adapted" prior to making serious observations. Night adaptation
generally requires about 10 to 15 minutes for most people.
3. Let the telescope "cool down" to the outside environmental temperature before making observations.
Temperature differentials between a warm house and cold outside air require about 30 minutes for the
telescope’s optics to regain their true and correct figures. During this period, the telescope will not
perform well. A good idea is to take the telescope outside 30 minutes before you want to start observing.
4. If you wear glasses and do not suffer from astigmatism, take off your glasses when observing through
the telescope. You can re-focus the image to suit your own eyes. Observers with astigmatism, however,
should keep their glasses on since the telescope cannot correct for this eye defect.
5. Avoid setting up the telescope inside a room and observing through an open window (or, worse yet,
through a closed window). The air currents caused by inside/outside temperature differences will make
quality optical performance impossible.
6. Perhaps most importantly of all, avoid "overpowering" your telescope. The maximum usable
magnification at any given time is governed by the seeing conditions. If the telescopic image starts to
become fuzzy as you increase power, drop down to a reduced magnification. A smaller but brighter and
sharper image is far preferable to a larger but fuzzy and indistinct one.
7. As you use your telescope more and more, you will find that you are seeing finer detail: observing
through a large aperture telescope is an acquired skill. Celestial observing will become increasingly
rewarding as your eye becomes better trained to the detection of subtle variations of resolution.
TELESCOPE MAINTENANCE
Cleaning the Optics
Perhaps the most common telescope maintenance error is cleaning the optics too often. A little dust on
the surface of the front correcting lens causes negligible degradation of optical performance; don’t clean
the outside surface of this lens unless really necessary. To remove small particles on the corrector lens
surface, use a camel’s hair brush (gently!) or blow off with an ear syringe (available from a local
pharmacy). If further cleaning is required, a photographic lens cleaner may be used. In any case, do not
clean the correcting lens by taking strong circular wipes with a piece of cloth or other material. Use a
white Kleenex-type tissue and make short, gentle radial wipes (from the center outward). Change tissues
several times when cleaning the entire lens surface.
Since all Model 2045 telescopes include a high-transmission magnesium fluoride coating on the
correcting lens, always take care during cleaning to avoid scratching this coating.
To clean the inside surface of the correcting lens, the entire correcting lens cell may be unthreaded from
the blue color main tube. Follow the same procedure to clean the inside lens surface as described above
and then re-thread the entire corrector lens in cell carefully back onto the blue main tube. Do not touch
or attempt to clean the secondary mirror surface, as scratches will almost certainly result! (The
secondary mirror is visible in the center of the correcting lens, when the correcting lens cell is unthreaded

from the main tube).
Importantly, do not remove the actual correcting lens from its machined cell housing for cleaning or other
purposes. You will almost certainly not be able to replace the correcting lens in its proper rotational
orientation, and serious degradation of optical performance may result.
Alignment of the Optical System
All Meade Schmidt-Cassegrain telescopes are precisely collimated (aligned) at the factory before packing
and shipment, and it is probable that you will not need to make any optical adjustments before making
observations. However, if the telescope sustained rough handling in shipment, you may need to
recollimate the optical system. Such recollimation is not difficult, in any case.
To check the collimation of your telescope, locate in the telescope a moderately bright (first or second
magnitude) star near the zenith. To perform the test, center the starpoint in the telescopic field with a low
power eyepiece, such as the 25mm eyepiece supplied as standard equipment. Defocus the image to fill
about 1/4 of the field of view. You will see in the out-of-focus image a circle of light with the darker
circular shadow of the secondary mirror somewhere within. If the darker shadow is well centered within
the lighter shadow(see (C), Fig. 4), your telescope is well collimated, but continue to read this section for
the more sensitive, high power tests to be described below. If the darker shadow is not so centered (see
(A), Fig. 4), follow this procedure:
1. Locate the three collimation set screws near centrer portion of the front corrector plate lens (see Fig. 3).
2. Note that the only optical alignment adjustment of the Model 2045 that is ever necessary or possible is
the tilt-angle adjustment of the secondary mirror. Adjustment of this tilt-angle is achieved by turning the 3
set screws (2), (3) and/or (4) in Fig. 3, located at the edge of the secondary mirror housing.
DO NOT AT ANY TIME TURN OR ADJUST THE CENTER SCREW (SEE (1), FIG. 3), LOCATED ON
THE OUTER SURFACE OF THE SECONDARY MIRROR HOUSING. THIS SCREW HOLDS THE
SECONDARY MIRROR IN PLACE IN ITS HOUSING!
DO NOT FORCE THE 3 COLLIMATION SET SCREWS PAST THEIR NORMAL TRAVEL AND BE SURE
TO KEEP AT LEAST ONE SCREW UNDER TENSION AT ALL TIMES SO THAT THE SECONDARY
MIRROR WILL NOT ROTATE IN ITS HOUSING. NOTE THAT THE SECONDARY MIRROR
COLLIMATION ADJUSTMENTS ARE VERY SENSITIVE: GENERALLY, TURNING A SET SCREW 1/2
TURN WILL HAVE DRAMATIC EFFECTS ON COLLIMATION.
3. While observing the defocused star image, note the direction in which the darker shadow is offset
within the lighter circle. Using the telescope’s slow-motion controls, move the defocused image to the
edge of the field of view, in the same direction as the darker shadow is offset.
Fig. 3: Collimation of the Optical System
13

4. Tighten the screw or screws in the same direction as the darker shadow is off-center and loosen the
other screw or screws. Continue this process until the defocused image is brought back to the center of
the telescopic field. If, after following these steps, the secondary mirror shadow is still off-center in the
out-of-focus star image, repeat procedures until the shadow is exactly centered.
5. Now proceed to a higher power (e.g. 9mm) eyepiece and repeat steps 3 and 4. Any lack of
concentricity at this point will require only extremely slight adjustments of the 3 set screws.
6. As a final check on collimation, examine the star focus image in-focus with a fairly high power (9mm or
shorter focal length) eyepiece, under good seeing conditions. The starpoint should appear as a small
central dot (the so called "Airy disc") with one diffraction ring surrounding it. Make very small adjustments
of the 3 set screws, if necessary, to center the Airy disc in the diffraction ring. With this final adjustment
performed, the telescope is collimated.
Fig. 5: Summary of the Collimation Procedure
(a) Note if the darker shadow is decentered, as shown, inside the lighter circles; (b) use the telescope’s
controls to move the image to the edge of the field in the same direction as the darker shadow is off
center; (c) tighten and/or loosen, as appropriate, the secondary housing’s 3 collimation set screws to
bring the image back to the center of the field; repeat (a) and (b), if necessary.
The Meade Model 2045 has been designed and manufactured for years of trouble free operation and
repairs should rarely be necessary. If a problem does occur, first write or call our Customer Service
Department. Do not return the telescope for servicing until you have communicated with us in this way,
since the great majority of problems can be handled without return of the telescope to us. When
telephoning or writing, please explain in detail the exact nature of the problem so that we may offer a
prompt remedial procedure. Be sure to include your full name, address and phone number.
1 A

BASIC SPECIFICATIONS:
MODEL 2045 4" (102MM) SCHMIDT-CASSEGRAIN TELESCOPE
Optical Design Schmidt-Cassegrain Catadioptric
Clear Aperture
102mm (4")
Focal Length
1000mm (40")
Focal Ratio (Photographic Speed)
f/10
Near Focus (approx.)
15 ft.
Resolution 1.1 arc secs.
188 lines per mm
Limiting Visual Magnitude
12
Limiting Photographic Magnitude
14.5
Image Scale
1.43 degs./inch
Maximum Practical Visual Power
35mm Film Coverage at Distances of:
300X
50 ft. 13.3" x 19.6"
500 ft.
11.8’x 17.3'
3000 ft.
70.5’x 103.5’
35mm Angular Film Coverage
1.38' x 1.96°
Telescope Mounting
Fork-type, double tine
Electronic Motor Drive
12Vdc Pulse Motor
Setting Circle Diameters Dec.: 4"; R.A.: 6"
Manual Slow-Motion Controls
Standard Accessories
Setting Circles
Dust Covers
Dec. and R.A.
Viewfinder
5x24mm
Eyepiece
1.25" O.D. 25mm (40X)
Eyepiece Holder/Diagonal Prism
Accepts 1.25” O.D. eyepieces
Tripod Legs (tabletop)
Battery Pack with Power Cord
Powers Obtained with Optional Eyepiece (Note 1):
2 pcs. Fixed Length
1 pc. Adjustable length
4mm 250X (500X)
6mm 167X (333X)
9mm
11lx (222x)
12.5mm 80X (160X)
18mm 56X (112X)
40mm
25X (50X)
Optical Tube Size
4.6" Dia. x 10" Long
Secondary Mirror Obstruction
Materials and Construction
1.8" Dia.: 20%
Tube Body
All Aluminum
Mirrors
Pyrex Glass
Telescope Size, Swung Down 7" x 9" x 16"
Carrying Case Dimensions
17" x 10" x 11”
Net Telescope Weight (approx.) 12 lbs.
Shipping Weight (approx.)
16 lbs.
NOTES:
(1) Numbers in parenthesis indicate Magnifying Powers when the specified eyepiece is used in
conjunction with the #126 2X Telenegative Amplifier. Note that, in any case, powers in excess of about
300X on the Model 2045 may be used to advantage only under the very best observing conditions.