Meade Instruments LX600 - Manual (Page 60)

AutoStar #497 HANDBOX
Appendix E
60
so that center tick mark on fork arm base
(Fig. 24, A) aligns with the tick mark on the
base (Fig. 24, B). Lock the RA.
e. Press ENTER. The telescope slews to Polaris.
f. Use the azimuth and latitude controls on the
X-Wedge to center Polaris in the fi eld of view.
Do not use the AutoStar II handbox during this
process. When Polaris is centered, press ENTER.
Lock the locking screws on the X-Wedge. The
telescope will then slew to an alignment star
and ask you to center it. Once you have done
tis press ENTER. The telescope is now polar
aligned. See AUTOSTAR II POLAR ALIGNMENT,
on this page, for more information.
At this point, your polar alignment is good enough for
casual observations. There are times, however, when you will
need to have precise polar alignment, such as when making
fi ne astrophotographs.
Once the latitude angle of the wedge has been fi xed and locked-
in according to the above procedure, it is not necessary to
repeat this operation each time the telescope is used, unless you
move a considerable distance North or South from your original
observing position. (Approximately 70 miles movement in North-
South observing position is equivalent to 1° in latitude change.)
The wedge may be detached from the fi eld tripod and, as long
as the latitude angle setting is not altered and the fi eld tripod is
leveled, it will retain the correct latitude setting when replaced
on the tripod.
The fi rst time you polar align the telescope, check the calibration
of the Declination setting circle. After performing the polar
alignment procedure, center the star Polaris in the telescope
fi eld. On the left fork arm, loosen the large smooth knob centered
in the setting circle. With the knob loose rotate the setting circle
until it aligns with 89.2 degrees with the pointer. While holding it
in place, tighten the large smooth knob.
Should you wish to use the manual setting circles, the RA
setting circle (Pg. 58, Fig. 20) must be calibrated manually on
the Right Ascension of a star every time the telescope is set up.
(The RA setting circle has two sets of numbers, the inner set
is for Southern hemisphere use, while the other is for Northern
hemisphere use.) Locate a star with which you’re familiar. Look
up the RA for the star in a star chart or other aid. With the star
centered in the telescope’s eyepiece, move the RA setting circle,
using one of knobs (Fig. 24, C), so that the RA of the star lines
up with the tick mark on the base of the telescope (Fig. 24, B).
Precise Polar Alignment
It should be emphasized that while doing casual observing,
precise alignment of the telescope’s polar axis to the celestial
pole is not necessary. Don’t allow a time-consuming effort at
lining up with the pole to interfere with your basic enjoyment
of the telescope. For long-exposure photography, however, the
ground rules are quite different, and precise polar alignment is
not only advisable, but almost essential.
Even though the LX600 ACF telescopes offers a very precise
and sophisticated drive system, the fewer tracking corrections
required during the course of a long-exposure photograph,
the better. In particular, the number of Declination corrections
required is a direct function of the precision of polar alignment.
Achieving precise polar alignment can be done with Starlocks
assistance or manually using a crosshair eyepiece. See Polar Drift
Alignment on page 43 for more information on using Starlock to
obtain a precise polar alignment. If you wish to manually obtain a
precise polar alignment, the Meade Astrometric Reticle Eyepiece
(see OPTIONAL ACCESSORIES, page 44) is well-suited in this
application, but it is also preferable to increase the effective
magnifi cation through the use of a 2X or 3X Barlow lens as well.
Follow the procedure on page 68, Appendix G: Manual Drift
Alignment to obtain a precise polar alignment without Starlocks
assistance. When performing this procedure, turn off the Starlock
in the Utilities menu.
Achieving precise polar alignment can be done with Starlocks
assistance or manually using a crosshair eyepiece.
AutoStar II Polar Alignment
AutoStar II provides three different (manual) methods for polar
alignment: Easy, One-Star and Two-Star.
One-Star Polar Alignment (Default)
Setup the telescope facing true north with the tripod level. Use
Fig. 24. Align tick marks to set the fork arms to 00 H.A. position.
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