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QHY PoleMaster Mount Leveling & Mount GoTo Syncing ...

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#1 Sealyons

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Posted 25 July 2018 - 03:31 PM

I'm strongly considering the purchase of a QHY PoleMaster to help cut down the time required for polar alignment (and increase the accuracy) for imaging.  My research so far has been really positive but I have some questions that I hope some of you who are using it can help me with.  

 

First, QHY says leveling of the mount is NOT required to get polar alignment with the PoleMaster.  Can users confirm this?  Are people still leveling anyway?  I guess that makes sense but just want to be sure.  And this may be a stupid question, but once you have polar alignment completed, how does that translate to your mount's GoTo system?  Not that it matters but I have both a SkyWatcher EQ6-R Pro & an Orion SkyView Pro mount and plan to share the PoleMaster between the mounts.  I'd assume one you have polar alignment, you'd only have to do a 1-star alignment to get the mounts GoTo system in-sync.  And then you should be able to use SynScan GoTo system to move to any objects you'd like to view.  Has anyone does this after polar aligning with the PoleMaster?  Is this the method to use?  Is there a better way?

 

What about EQMOD?  Has anyone used EQMOD after polar aligning with PoleMaster?  Any issues?  Again, my assumption is that once you have polar alignment, it should be relatively easy to sync up with whatever GoTo system you're using.  Interested in what people are finding.  Thanks for any guidance.



#2 rgsalinger

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Posted 25 July 2018 - 04:29 PM

You don't need to level.  Period. However it will make things easier to do because then the alt/az movements will look like up/down and left/right which makes it faster to get the system accurately aligned to the sky.

 

PA helps any Goto system, but you may still need to do a multi star calibration, depends on the FOV. Personally, I don't bother with a mount model when I'm portable. Instead I rely on Platesolving. The cheapest software alternative that has plate solving is Sequence Generator Pro.

 

There is no issue with EQMOD and Polemaster. I used this combination for two years and never saw any interaction.

 

Rgrds-Ross



#3 wtd1114

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Posted 25 July 2018 - 05:19 PM

I can confirm two of your questions...

 

Yes, you do not have to have a level tripod.  If you think about it, pointing to NCP has nothing to do with being level with the earth...  Being level is just kind of nice to have.

 

Yes, you can do just a 1-star alignment and have accurate GOTO if 1) you have good polar alignment, 2) you have eliminated the cone error in your mount/dovetail bar.   In your mount EQ6 R manual there is a section on how to eliminate cone error.  Eliminating cone error entails adjusting the little screws at the ends of your dovetail bar.  This makes the scope OTA optical axis orthogonal to the RA axis.   The 1-star alignment is what I use.  I have found that if I have good polar alignment with a Polemaster and I do a two-star alignment, I have found it not as accurate as a 1-star.  If you have gone through the procedure to eliminate the cone error in you setup, there is no need to do a three-star alignment.

 

Can't help you with the eqmod question-  don't use it at this point.  I don't why it will not work with eqmod since it should be very accurately polar aligned with the Polemaster.

 

Willis



#4 FlankerOneTwo

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Posted 25 July 2018 - 09:24 PM

As stated above you do not need to level for reasons of polar alignment, as you can use the manual alt-az adjustments to point the RA axis at the north pole, even if the mount is lying on its side.

You may wish to level the tripod / mount (or at least be close) for reasons of balance on the tripod and to prevent tipping, although this shouldn't be a huge issue unless the mount is seriously off kilter. It does make adjusting for alignment more straightforward especially if you are drift aligning, but is not a big deal if you are solely using a PoleMaster.

 

Polar alignment should not be confused with GoTo calibration. PA aligns the mount's mechanical axis with celestial north pole. GoTo calibration "aligns" the mount's (or software's in the case of EQMOD) sky model and computed axis with the mount's mechanical axis and performance. You would think they would be the same but often they are not, especially if the OTA is not perfectly aligned to the mount along any axis.



#5 Fernando134

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Posted 26 July 2018 - 07:26 AM

I'm strongly considering the purchase of a QHY PoleMaster to help cut down the time required for polar alignment (and increase the accuracy) for imaging.  My research so far has been really positive but I have some questions that I hope some of you who are using it can help me with.  

 

First, QHY says leveling of the mount is NOT required to get polar alignment with the PoleMaster.  Can users confirm this?  Are people still leveling anyway?  I guess that makes sense but just want to be sure.  And this may be a stupid question, but once you have polar alignment completed, how does that translate to your mount's GoTo system?  Not that it matters but I have both a SkyWatcher EQ6-R Pro & an Orion SkyView Pro mount and plan to share the PoleMaster between the mounts.  I'd assume one you have polar alignment, you'd only have to do a 1-star alignment to get the mounts GoTo system in-sync.  And then you should be able to use SynScan GoTo system to move to any objects you'd like to view.  Has anyone does this after polar aligning with the PoleMaster?  Is this the method to use?  Is there a better way?

 

What about EQMOD?  Has anyone used EQMOD after polar aligning with PoleMaster?  Any issues?  Again, my assumption is that once you have polar alignment, it should be relatively easy to sync up with whatever GoTo system you're using.  Interested in what people are finding.  Thanks for any guidance.

I use Polemaster with both mounts, Atlas Pro and Mach1. For the Atlas Pro, after polar align with Polemaster, I use Eqmod + Cartes du Ciel. Eqmod to create a Point Model, that you may save for other observing/imaging nights. After polar align with Polemaster, I sinc to a star; USUALLY, the star is not in the FOV of the camera, so the Point Model in Eqmod will help on that.



#6 redtag

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Posted 21 March 2019 - 07:28 PM

Post #2 said SGP was the cheapest software that supported plate solving. I have been using a much cheaper product called Astro Photography Tool (APT) and the plate solving is fast and accurate. 

 

EDIT: This is my first post since joining CN and I see that I am going to have to create a signature...Dave


Edited by redtag, 21 March 2019 - 07:29 PM.



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