An alternative way to polar align?

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cloud_cover
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An alternative way to polar align?

Post by cloud_cover »

I've finally committed to a nice new GEM mount :) The guys who met me that time at Punggai also know I'm very much into photography (in general) and would like to extend that interest into Astrophoto.
So, I've learnt that a good Polar alignment is very important when setting up the mount for imaging, especially unguided (which will be the case for a while, for cost reasons)
Having said that, Polaris is not visible in Singapore so its impossible to use a polar scope and I understand the method locally is rough alignment followed by drift alignment.
However, I was wondering if this method will work for GOTO mounts:
1. After an approximate polar alignment, command the GOTO to slew to any visible star.
2. However, instead of using the controller RA/DEC controls to align to star, instead use the az/lat controls of the mount to align onto the star instead
3. Rinse and repeat until GOTO perfectly centers stars.
My thinking is this: The GOTO knows precisely where a star is supposed to be in the sky and will slew to those RA/DEC co-ordinates on the assumption the mount is level and perfectly polar aligned. So if the initial GOTO is off, then the "fault" must lie with mount alignment. So instead of correcting electronically (using the computerized GOTO alignment), why not manually correct so that the polar alignment is now better refined?
Of course I'm not suggesting this will replace drift alignment per se, but maybe its an alternative way for a reasonably good align?
Actually I think (but am not sure) that this is the basis for Celestron's all-star polar align.
I don't actually have a mount/scope yet so I don't know if this will work, but what do you guys think? :)

Off topic: 100th post!!!
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