New to Sharpcap and it's polar alignment

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Fivelpolar
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New to Sharpcap and it's polar alignment

Post by Fivelpolar » Fri Jan 19, 2018 4:21 am

Hello again (was on the bugs forum).
I understand that for GOTO plate solving I must have the mount driver installed and open, and the mount turned on.
My question is for polar aligning only.
Do I need to have the mount turned on and setup the same way, or can I just do the polar alignment with the installed plate solving apps and indexes?
Also, I noticed, at the bottom of the polar align screen that my supposed location was no where near to my location.
Is the a settings within Sharpcap where I can enter that data?

Fivelpolar

cuivenion
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Re: New to Sharpcap and it's polar alignment

Post by cuivenion » Fri Jan 19, 2018 8:42 am

Polar alignment is completely separate from the GOTO plate solving. Your mount doesn't have to be connected and you don't need plate solving software for polar alignment, Sharpcap handles it on its own. Can't help with the location bit I'm afraid.

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admin
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Re: New to Sharpcap and it's polar alignment

Post by admin » Fri Jan 19, 2018 7:44 pm

Yep, no need for a plate solving program for polar alignment - SharpCap has a built in database and plate solving engine (but only for the area within 5 degrees of each pole). No need for an ASCOM mount either.

cheers,

Robin

Fivelpolar
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Re: New to Sharpcap and it's polar alignment

Post by Fivelpolar » Sat Jan 20, 2018 12:38 am

Thanks to both of you for your replies.
I did get the program to work, but had to install Astrotortilla et. al.
I also had to go back to Sharpcap Pro version 3.since the Beta version I had is not stable.
All that worked except when it came to adjusting the mount, I could not get any visible improvements.
The thin clouds probably di not help.
I read the following on a CN forum "Posted 06 December 2016 - 01:16 AM
When you start the first solve is in home position, nominally your pole (NCP or SCP). After rotation it does the second solve. As soon as it has solved the rotation position return it to the home position for ALL adjustments. Do not adjust in the rotated position. If you try to adjust in the rotated position you will make a mess of your Initial solve. Sharpcap website and the instructions are not very clear about that sequence and when and where you adjust. "
And wonder if this is the correct mount position for making the adjustments?
I will try more when the skies are clear enough.

Fivelpolar

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Re: New to Sharpcap and it's polar alignment

Post by admin » Sat Jan 20, 2018 11:16 am

Fivelpolar wrote:
Sat Jan 20, 2018 12:38 am

I read the following on a CN forum "Posted 06 December 2016 - 01:16 AM
When you start the first solve is in home position, nominally your pole (NCP or SCP). After rotation it does the second solve. As soon as it has solved the rotation position return it to the home position for ALL adjustments. Do not adjust in the rotated position. If you try to adjust in the rotated position you will make a mess of your Initial solve. Sharpcap website and the instructions are not very clear about that sequence and when and where you adjust. "
Don't do this! It's not how it's designed to work and it's not a way I've tested it. It might work passably, but I wouldn't like to say for sure.

Correct procedure is

* Start in one position - home position is standard but it can be any position with Dec = +90 (or -90 for SH)
* Rotate 90 degrees to second position (you can get away with less, but 90 degrees gives the best accuracy)
* Adjust without making further rotation changes to the mount.

There is nothing to stop you from starting with the RA position 90 degrees from home and then rotating back to home for the second position.

cheers,

Robin

cuivenion
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Re: New to Sharpcap and it's polar alignment

Post by cuivenion » Sat Jan 20, 2018 3:27 pm

Hi Robin, just thought I'd check. I don't rotate to dec +90 with a great deal of accuracy, I just unclutch rotate to just past 90 degrees by sight and reclutch. The home position is rough too. Does this matter? Do those positions need to be as accurate as possible?

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oopfan
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Re: New to Sharpcap and it's polar alignment

Post by oopfan » Sat Jan 20, 2018 4:48 pm

Hi, maybe my experience can help. I like to think of it like this: Many people don't have a Polar Finder Scope (you know the type that is an integral part of your equatorial mount's polar/right ascension axis.) I don't have one. People who do have one don't like it much because you have to get on your knees and crane your neck to look through it. Wouldn't it be nice to use our telescope and camera instead? This is where SharpCap comes in. First off, let me say that the benefit of using a Polar Finder Scope is that it is machined to be perfectly aligned with your polar axis. That's not true of your telescope; it can freely rotate on the right ascension and declination axis by releasing clutches. So the first step is to try to get your telescope and your polar axis parallel to each other. It doesn't have to be perfect -- close is good enough. I'm anal retentive so I use a bubble level and a cardboard cutout of a right-triangle for my latitude. And then at the beginning of astronomical twilight, I begin the next step which is to release your mount's azimuth axis and rotate the mount until it roughly points at Polaris. There is no need to look through an eyepiece, just eyeball it. And then fire up SharpCap and launch the Polar Alignment tool. It does not matter where you start. When SharpCap tells you to rotate 90 degrees, release the clutch on your right ascension axis and rotate approximately 90 degrees -- it doesn't have to be perfect. The rest of it is smooth sailing. I routinely get within 15 arc seconds of NCP within 10 minutes of starting SharpCap. My camera is a ZWO ASI120MC on a 160mm Orion finder/guider scope. I use MONO8, 4 second exposure and gain of 50. It is important to have a wide enough field of view.

robrj
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Re: New to Sharpcap and it's polar alignment

Post by robrj » Sat Jan 20, 2018 5:37 pm

Fivelpolar wrote:
Sat Jan 20, 2018 12:38 am
Thanks to both of you for your replies.
I did get the program to work, but had to install Astrotortilla et. al.
Astrotortilla is only necessary if you're going to plate solve (which is separate from Polar Aligning). If you're going to use Plate Solving, I'd recommend turning the mount on before starting Sharpcap, otherwise Sharpcap will complain that it can't connect to the mount. You don't have to align it until after the Polar Align, just turn it on.

Fivelpolar
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Re: New to Sharpcap and it's polar alignment

Post by Fivelpolar » Sun Jan 21, 2018 3:53 pm

Thanks to all for your informative replies.
I know that I can get this accomplished, once we have a clear night.

Clear, dark skies to all.

Fivelpolar

Fivelpolar
Posts: 17
Joined: Fri Dec 01, 2017 10:53 pm

Re: New to Sharpcap and it's polar alignment

Post by Fivelpolar » Fri Jan 26, 2018 5:59 am

Hello again to all.
Tonight I finally got to perform the polar alignment and for the most part it went well.
I do have one question/concern though.
When I was getting close to the "excellent" alignment, suddenly the result changed without me touching the mount. It jumped from Excellent to fair and even poor several times.
I re did the routine from the beginning a few time with the same results.
What are the most likely culprits that can cause this to happen?

Fivelpolar

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