Mismatch between SharpCap and PHD2 polar error

Using SharpCap's Polar Alignment feature
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dthomson39
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Joined: Tue Mar 20, 2018 4:48 pm

Mismatch between SharpCap and PHD2 polar error

#1

Post by dthomson39 »

Hi

I have been using the Polar alignment feature for a while now and love it. Like many here I can easily get to within 5 arc seconds and Excellent with a bit of careful adjustment - Polaris is not in the FOV I'm pretty sure its not anyway so there is some cone error that may need sorting - I think you said that a few degrees is OK so I hope that is all it is on my setup. How critical is it to get good polar alignment if the route runs smoothly every time and I can get really close according to Sharpcap.

When I run PHD2 the calculated polar error seems to always be quite a bit higher than that reported by Sharpcap - any reasons why this might be?

I have tried to get everything lined up - took the head off the tripod mount on the HEQ5 Pro and levels it - the bubble on the head when reattached was way out so hopefully the mount is level (is this important or only a nice to have?)

Is there anything else that is critically important (I take note of the flex issue but everything is locked up tight.

Regards

Dave
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admin
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Re: Mismatch between SharpCap and PHD2 polar error

#2

Post by admin »

Hi,

I am always interested in getting feedback from people who see this sort of problem. I have seen a handful of reports of this sort of measurement. In two or three cases we have tracked it down to flexure or bearing issues in the mount leading to poor rotation. In most cases however I have not heard back so no conclusions could be made :(

If you haven't already seen the polar alignment troubleshooting page (https://www.sharpcap.co.uk/sharpcap/fea ... leshooting) then please give it a read - it lists the most common causes of problems and also gives some hints on how to solve the problem or determine if it is affecting you. In particularly there is an example of the difference that a loose cable can make which might surprise many people.

If that page doesn't help, please come back and we can investigate further.

thanks,

Robin
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