Polar Align

Buckrogers
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Polar Align

Post by Buckrogers » Wed May 13, 2020 2:25 pm

Greetings,

I have a Celestron Neximage 10. Can I use the Polar Align Tool in SharpCap? I do have SharpCap Pro.

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Re: Polar Align

Post by admin » Wed May 13, 2020 6:44 pm

Hi,

I'm not sure that anybody has reported using that particular camera, but at one point I had a NexImage 5 on loan from Celestron and I had that working with SharpCap.

The checklist for getting polar alignment to work is

* A suitable field-of-view – ideally 1° by 0.75° or thereabouts. Fields of view from about half this up to about three or four times this should work.
* The ability to see and detect stars in a single frame when pointed near the pole – this usually requires a gain control that you can turn up and exposure control that goes to at least a couple of seconds. You may need to adjust the star detection settings in the polar alignment tool, but it's always best to adjust the gain and exposure first.

The Neximage 5 and 10 were basically aimed at high speed solar system imaging - I'm not sure if they have enoug gain/ long exposure available to make this work and the very small pixels could also work against you.

cheers, Robin

Buckrogers
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Re: Polar Align

Post by Buckrogers » Wed May 13, 2020 7:09 pm

Hi,

I will try this out and let you know. Thank you so much.

Buckrogers
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Re: Polar Align

Post by Buckrogers » Sat May 23, 2020 2:39 am

Hi,

Well I've tried pretty every night to no avail. What I see is a message that says Polar align plate successful in 1s or something like that. I see 15 detected stars exposure is 1s gain is maxed played around with this a lot also changed the min pixel to 3, played with noise reduction and black threshold and get nothing. Not sure what to do next but to me sounds like this camera can't do the polar align.

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Re: Polar Align

Post by admin » Sat May 23, 2020 7:47 pm

Hi,

I think the next step is for you to capture a couple of images during the process – just press the snapshot button. If you can share those images with me then I can look at them to see if there's any way that the plates solving and polar alignment can work on them.

The best way to share large images is usually to upload them to dropbox, one drive or Google Drive and then post the sharing link in here in the forums.

Cheers, Robin

Buckrogers
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Re: Polar Align

Post by Buckrogers » Sun May 24, 2020 3:34 am

Hi,

Tonight I did some testing again. I'm not sure what you are looking for in snapshots but I have uploaded them here:

https://1drv.ms/u/s!AnHn-qbt7We5oDNcWTv ... b?e=Wl4uXu

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Re: Polar Align

Post by admin » Sun May 24, 2020 8:35 pm

Hi,

I've just had a look at those images and I can't see any stars in them myself – there is a lot of noise, some of which might be picked up as false stars by the polar alignment code depending on the star detection settings, but I certainly wouldn't expect images like that to work since no stars are obvious when looking at the images by eye.

Are you sure that your focus is correct? If possible I would also try increasing exposure until you can clearly see stars in the image.

Cheers, Robin

Buckrogers
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Re: Polar Align

Post by Buckrogers » Sun May 24, 2020 9:36 pm

Hi Robin,

When I took the snapshots, there were at least 15 stars detected. I"ll double check my focus and increase the exposure. Will try again on a cloudless night and upload the pics. Thanks for your assistance :)

Buckrogers
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Re: Polar Align

Post by Buckrogers » Sat Jun 06, 2020 3:57 pm

Hi,

I finally get a cloudless night so will try again the Polar align. When you say focus, you are talking about the focus assistant in SharpCap right?
Will let you know how things go.

chongo228
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Re: Polar Align

Post by chongo228 » Sat Jun 06, 2020 5:17 pm

Buckrogers wrote:
Sun May 24, 2020 9:36 pm
Hi Robin,

When I took the snapshots, there were at least 15 stars detected. I"ll double check my focus and increase the exposure. Will try again on a cloudless night and upload the pics. Thanks for your assistance :)
You said you were around 1 sec exposure with max gain...I'm guessing your 15 stars detected were all noise and not really stars. A cooled camera might be able to get away with max gain but I doubt a non-cooled camera could.

Go with low to medium gain and expose for 15 seconds. Once it starts solving back the exposures down 1 second at a time until it fails. It's been a while since I've aligned with my guide-non cooled camera but I want to say 7-8 seconds on my ASI174 is what it took.

To start out just focus and set exposures until you can clearly see the stars. If you can see them SC should easily be able to find them.

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