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Polar Imaging - alignment technique - anyone tried this?
Came across this technique in the MaximDL how to guides ...
Paul Boltwood has pioneered a very simple and effective technique for polar alignment. Using a planetarium program, create a chart of the area around the pole (north or south). Make sure that the proper pole location is labelled on the chart.
Next, do a rough polar alignment, and then take a 60-second CCD image of the pole. Halfway through the exposure, rotate the telescope about the RA axis as far as it will go. Move it just fast enough to complete the arc in 30 seconds. You will create an image with the stars clearly visible, plus a set of near-circular arcs centered on the position of the telescope’s pole. You can now easily see the difference in position between the telescope’s polar axis and the correct pole location. In fact, you can measure this distance in X and Y using the Information window, and get a very accurate number. Now adjust the mount by that distance (tip: set a rapid binned exposure mode and watch the stars move as you adjust). After one or two iterations you have an extremely accurate polar alignment.
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