Polemaster vs guidescope

[hamel]

I have been using the Polemaster camera with SharpCap for PA. The alignment agrees well with what I get using the Polemaster software. Last night I decided to compare the PA I get with the Polemaster camera and SharpCap with the PA I get with my ZWO guidescope and ZWO camera. The difference was more than 12 minutes! I repeated the procedure twice with the same results. The guidescope is well aligned with my OTA though I know that isn't necessary. I can see the North Star in my guide scope image so I know I'm not too far off. Any one have any ideas to explain that?

[admin]

Hi,

now and then someone posts a similar problem perhaps showing an offset between the SharpCap polar alignment figure and a drift alignment measurement. Whenever we've tracked down a cause for this it's always come down to the guide scope moving relative to the mount as the mount is rotated about the RA axis. This can be caused by something as simple as a dangling cable or just the mounting of the guide scope not being rigid enough. If you check out the polar alignment troubleshooting page here – https://www.sharpcap.co.uk/sharpcap/fea ... leshooting – there is more in-depth discussion of the problem including an explanation of how to work out whether it's the cause of not.

Cheers, Robin

[hamel]

Thanks! I'll check it out.