Having trouble with Polar Alignment plate solving

[GOT_SC]

Hello all,
I've recently acquired a used Equitorial platform for my Dob which I want to try for EAA use.

The Dob is an Orion 10" with a focal length of 1200
The camera is the very common ZWO 294

Sharpcap is able to perform plate-solving through the TOOLS \ PLATESOLVE feature

But it does not appear to be able to plate-solve within the polar alignment feature.

I have the scope centered on Polaris and select Polar Alignment

The system displays the polar alignment intro screen
It is waiting for the user to press the NEXT button
When I press the NEXT button - the system is supposed to take the first image and plate-solve
But it doesn't appear to be able to do that
It remains in that screen - trying to plate-solve - apparently unsuccessfully

Any suggestions on what I should try or adjust or do would be greatly appreciated.
Sincere thanks!

[admin]

Hi,

the polar alignment uses a slightly different plate solving approach, which is optimized for speed, leading to some different requirements. Basically you need

* A field of view of at least 0.5 degrees in each direction (you should be fine - 1200mm F/L with your 294 camera gives 0.9x0.6 degrees)
* Plenty of stars visible (20 or more)
* Already pointing at an area within about 5 degrees of the celestial pole

Since your field of view is OK, it's the last 2 that you should check. SharpCap reports the number of stars being detected as part of the polar alignment information - if that number is low, increase gain/exposure or the star detection sensitivity.

If you have the Tools->Plate Solve functionality working, then you can use that to check that you are starting out within 5 degrees of the celestial pole (North of 85N declination).

There is more info on troubleshooting polar alignment problems here : https://docs.sharpcap.co.uk/4.1/#Troubl ... 0Alignment

cheers,

Robin

[GOT_SC]

Thank you Robin

Within the Polar alignment module - there is a feature where one can select different max count of stars
And it also displays the number of stars it sees
I think if I remember correctly - it was indicating it was detecting around 80 stars
But I believe it was also indicating it was only using 15 stars

So perhaps the reason why it was not successfully solving is because it was lacking 5 more stars in order to complete a reading.

I'll check out the link you provided
Sincere thanks!

[admin]

Hi,

detecting 80 and using 15 should normally be perfectly fine, so I would suspect that you may have been pointing at a position too far from the pole (more than 5 degrees away). Checking the 'Plate Solve Only' results will let you know for sure.

cheers,

Robin