|Iterative Polar Alignment
This method of polar alignment is reasonably fast, simple, and should work with most any polar GOTO scopes and mounts such as the Meade LX200 Classic, LX200GPS, ETX, Orion Atlas, Celestron, Losmandy, Astrophysics, LXD55's, etc. In other words, I have used the technique on German Equatorial Mounts as well as Fork Mounts and found that the result is accurate enough for CCD imaging. I have achieved integrations up to 1 minute at f/6.3 and nearly 2 minutes at f/3.3 using this method. At first reading, this technique may seem complicated but I assure you that once you get used to it, it is very fast and accurate. I can usually get polar aligned in about 20-minutes using this method.Before performing the procedure below, adjust your finder scope as accurately as you can. This only takes a couple of minutes and will help with the alignment process
Troubleshooting, Pitfalls and Traps:
The only problem I have encountered using this method, and you may too, is that the sequence sometimes does not converge. That is, your GOTO's keep "hopping around" and landing on one side or the other of Polaris and the alignment star. If this occurs, it is most probably because the alignment star has the same, or nearly the same RA as Polaris (2hrs 30min). It is best to choose an alignment star that is well away (i.e. 3-hours or more) from the RA of Polaris. If Autostar picks an alignment star with nearly the same RA as Polaris, the sequence probably will not converge. What's worse, the sequence may *appear* to converge because the GOTO's may center both Polaris and the alignment star, but there can still be a large polar alignment error. The star Hamal is a perfect example of a star NOT to use as an alignment star.
Bottom line...Make sure that the alignment star you use is more than 3 hours away from the RA of Polaris. If you do this, there should be no problems.
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Iterative Polar Alignment