Rotating back to original position - alignment rating.

Using SharpCap's Polar Alignment feature
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autonm
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Joined: Mon Jan 18, 2021 7:25 pm

Rotating back to original position - alignment rating.

Post by autonm »

If I start at home position - and going through the workflow - I achieve 'excellent' alignment after rotating 90degrees etc - should I expect that if I return back to it should also say 'excellent' if I continue to let it plate solve?

or if I 'stopped' after achieving 'excellent' - and then restarted it up again - should I expect home position to show excellent?

... or is this not possible because I am taking the two differences between two points and the adjustments is being made between those two points?

Thanks
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admin
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Re: Rotating back to original position - alignment rating.

Post by admin »

Hi,

if you run the polar alignment once, make your adjustments and end up in the rotated position, you should then be able to restart polar alignment and run it again, this time moving from the rotated back to the home position. You should get a result that is very close to your original adjusted result.

If you find that you adjust to get an excellent result on the first run and then you get a much worse result when rotating back, you probably need to check to see if your camera or guide scope is flexing or moving as the mount is rotating – that's the usual cause. At dangling USB cable that is hanging from the back of the camera is enough to cause this problem – you should cable tie your cable so that the weight of the cable is not pulling on the camera or guide scope.

Cheers, Robin
Verdi1918
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Joined: Thu Apr 29, 2021 6:29 pm

Re: Rotating back to original position - alignment rating.

Post by Verdi1918 »

Hi,

I am a newbie dealing with the same or almost the same question/problem. I have just tried twice to Polar align with SharpCap. There was no issue with plate solving and reaching "EXCELLENT" polar aligment just within a few minutes. Once I was ready to start photo session, I realised I don't know it will keep pollar aligment once dovetail rotated to the desired position. I stacked for a while. I have rotated back to home position but not starting a new alligment procedure. I ended up with SharpCap telling me, I am far away from Polar Star. I started again and after I reached "EXCELLENT", I did it again the same way. Also this time SharpCap told me, that I am away from Polar Star. Reading what you said, I was wondering, would I get different results starting the whole procedure before moving dovetaile back to the home position?... In other words, my question is: once polar alligment is finished, should my tracker keep this point whenever tracking head rotated or should the whole process been repeated before tracking head rotated to aim a new target?

Regards,

Jarek
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admin
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Re: Rotating back to original position - alignment rating.

Post by admin »

Hi,

the alignment should only need to be done once each evening (each time you set up) - there is no need to re-do the alignment before visiting a new target. This is providing that you do not disturb the mount base/tripod once you have aligned. If there is a disturbance (for instance you accidentally move the tripod or the ground is soft and the legs sink slowly) then it is worth checking your alignment and making adjustments if necessary.

cheers,

Robin
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