Meade Instruments LX200 - Manual (Page 41)

Meade Instruments Corporation - Meade LX200 Instruction Manuals
[ toc ] b) POLAR
POLAR allows you to use the LX200 mounted on its' optional
Equatorial Wedge (see Appendix A) for long exposure
astrophotography as well as visual work. With the LX200
powered up, the POLAR file option selected, the Field Tripod
leveled, the telescope should be adjusted so that the Declination
Setting Circle (3, Fig. 3) is set to 90 degrees (see Fig. 4), and to
the 00 hour angle (HA) in Right Ascension (in this position, the
Viewfinder (Fig. 3) is up-side down, the R.A. Pointer (9, Fig. 3),
the 00 line of the R.A. Setting Circle (10, Fig. 3), and the Hour
Angle Pointer (16, Fig. 3) match up), you are ready to start. (If
you do not start at the 00 H.A. position, the telescope it will point
to the ground instead of the sky, when the Keypad display
chooses its' second star.) Press the ENTER key and the LX200
will determine and slew to the precise off-set of the pole star in
Declination and Right Ascension.
At this point you need only aim the instrument at the pole star
(see Appendix B, section 3. Precise Polar Alignment if the pole
star is not visible) and center it in the eyepiece field using only
the Altitude and Azimuth adjustments on the Equatorial Wedge
(see Appendix A). Once done, you again press the ENTER key
and the LX200 will choose and slew to a very bright star that is
overhead and can usually be seen in the field of view of the
viewfinder. At this point, center the bright star using only the
Right Ascension and Declination adjustments of the telescope
(either manually by loosening the locks only or electrically), then press ENTER. You can now access every
every function of the LX200 including the Smart Drive.
[ toc ] c) Refined Polar Alignment
Astrophotographers routinely require polar alignments of the highest accuracy for the finest guiding
characteristics. Your initial polar alignment can be refined by using the LX200's electronics by using a
slightly different method in POLAR menu option. The routine outlined below should be performed in two or
three 15 minute intervals. At each interval the telescope will slew to the area where the pole star should be
centered in the optics. You may find that the pole star is somewhat off-center in the eyepiece showing the
alignment error that may have been made during your initial setup. Re-center the pole star during each
interval exercise using the Equatorial Wedge adjustments only (see Appendix A) in Altitude and Azimuth,
then follow the rest of the routine.
Return to the POLAR menu option in the TELESCOPE mode and press the ENTER key.
Ignore the Keypad display instructions to return the telescope to 90 degrees in Declination and 00 HA.
Instead, press the GOTO key and the LX200 will slew to the calculated position of where the pole star
should be.
Re-center the pole star in the field of view in the eyepiece using only the adjustments on the Equatorial
Wedge (see Appendix A) in Altitude and Azimuth.
Press the ENTER key, and the LX200 will once again slew to a bright star overhead. Center this star using
the N,S,E, or W keys and press ENTER. Note: Pressing the MODE key at any point in the alignment
routine will abort the routine and exit to the top menu.
After each 15 minute interval you will find that the pole star becomes more accurately centered each time.
You can repeat the intervals as often as you like to obtain the highest accuracy. An optional illuminated
reticle crosshair eyepiece* makes the job of centering the star easy.
There may be situations when it is impossible to see the pole star due to something blocking your line of
sight. In such an occasion, just press the ENTER key next to the POLAR option so that it has a check next
to it and follow the Precise Polar Alignment instructions in Appendix B to this manual. You will require the
use of an illuminated reticle crosshair eyepiece* to complete the task. Once finished, follow the steps in
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