iOptron IEQ75-GTTM instruction manual Polar Alignment, Polar axis adjustments

Lat. Adjust. Lever

Azi. Adjust. Knob

Latitude Adjustment Knob

Figure 10. Adjust latitude

Unscrew the Latitude Adjustment Lever from the Latitude Adjustment Knob as shown in Figure 10. Turn the Latitude Adjustment Knob to set your current latitude, using the Latitude Adjustment Lever for a fine adjustment, if needed. At this point, with the mount level and pointed North, and the latitude set, the Polar Axis (R.A. axis) should be pointing very close to the NCP and Polaris.

CAUTION: For safety reasons, always adjust the latitude without an OTA and/or counterweights installed. Also, it is much easier to make this precise adjustment without a load on the axis being adjusted.

STEP 5. Polar Alignment

As explained in the introduction, an equatorial mount must have an accurate polar axis alignment in order to track properly. With the iOptron innovative Polar Scope and Quick Polar Alignment procedure, you can do a fast and accurate polar axis alignment.

Figure 11. Polar Scope Dial

As indicated in Figure 11, the Polar Scope Dial has been divided into 12 hours along the angular direction with half-hour tics. There are 2 groups, 6 concentric circles marked from 36’ to 44’ and 60’ to 70’, respectively. The 36’ to 44’ concentric circles are used for polar alignment in northern hemisphere using Polaris. While the 60’ to 70’ circles are used for polar alignment in southern hemisphere using Sigma Octantis.

Polar axis adjustments

Whenever polar axis adjustments are required, loosen the four Azimuth Locking Screws and adjust the Azimuth Adjustment Knobs to do a fine adjustment of the mount in the azimuth direction. Tighten

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