Three Star Alignment; Solar System Align; Polar Iterate Align; View Model Error - iOptron CEM70G Instruction Manual

After the two-star alignment, the altitude and azimuth errors will be displayed. This number can
be used to fine tune the polar alignment.
For example, if the screen shows 7.5" low and 4.3" east, it means that THE MOUNT axis is
pointing low and to the east of the Celestial Pole.

5.3.4. Three Star Alignment

The three-star alignment will further determine the cone error between the OTA and mount axis.
The system will use these data to calculate the goto model. If the cone error is big enough, it is
suggested to shim the OTA in DEC to minimize it.
Press MENU => "Alignment" => "Three Star Alignment." A list of alignment stars that are
above the horizon is computed based on your local time and location. With the mount at the Zero
Position, use the▲ and ▼ buttons to select the first alignment star and press ENTER. Center the target
in your eyepiece using the arrow keys. Press ENTER when finished. The hand controller will prompt
you to choose a second star. Select third star after the mount aligned to the second star.
The system will display the pointing and cone errors after the three star alignment accepted.
The system will update the pointing model accordingly.

5.3.5. Solar System Align

This function uses a planet or the moon as an alignment object. Press MENU => "Alignment"
=> "Solar System Align" for a list of available alignment objects.

5.3.6. Polar Iterate Align

This alignment method allows you to polar align the mount even if you cannot view the Celestial
Pole. Press the MENU button, then select "Alignment" and "Polar Iterate Align". The HC will display a
list of bright alignment stars near the meridian as Alignment Star A. Follow the HC instructions to move
Alignment Star A to the center of the eyepiece using a combination of the Latitude Adjustment Knob
and the "◄" and "►" buttons. Press ENTER to confirm the settings. Next, select a bright star that is
close to the horizon as Alignment Star B. Center it using the Azimuth Adjustment Knobs and the "◄"
and "►" buttons (the "
The telescope will now slew back to Alignment Star A to repeat the above steps. The iteration
can be stopped when it is determined that the alignment error has been minimized. Press the BACK
button to exit the alignment procedure.
NOTE: It is highly recommended to use an eyepiece with illuminated crosshairs for accurate
centering.
NOTE: The movement of the alignment star in your eyepiece may not be perpendicular
depending on its location in the sky.

5.3.7. View Model Error

This will display linear RA error, linear DEC error, polar misalignment, non-perpendicular
between OTA and DEC, and non-perpendicular between HA and DEC.

5.3.8. Clear Alignment Data

This will clear all alignment data created during one star, two star or three star alignment
process. If you are controlling the mount using planetarium software via ASCOM, and the software has
its own alignment function, please clear the alignment data.
▲" and " ▼"
buttons will not function). Press ENTER to confirm the settings.
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