#1  
Old 09-05-2019, 05:59 PM
tornado33
Registered User

tornado33 is offline
 
Join Date: Jan 2005
Location: Newcastle, NSW, Australia
Posts: 3,931
Sharpcap Polar Alingment

Hello all.
Since coming across Sharpcap's Polar Alingment function Im amazed at how easy and fast it is to do. We have reactive clay in the yard and without a deep permanent pier polar alignment can change over time. So while still twilight as soon as theres enough stars for Sharpcap to platesolve I do the polar alingment. Have a look at how close I got it, 5 arc secs and it takes atmospheric refraction into account after inputting ones location co ords. The polar alignment was complete even before it was dark. I use an 80mm short refractor to do it with piggybacked on the 10 inch scope.

This now allows me to do 15 to 20 minute subs without making any dec corrections, and makes the Argo Navis more accurate as well. last saturday night I tested it at another location when i took my Sampson Mount to a Newcastle Astro Society viewing night at Speers point, we set up in the local pool car park, on bitumen. Again I got precise alignment. very happy with this polar alignment function
Scott
Attached Thumbnails
Click for full-size image (20190507_182205s.jpg)
148.1 KB90 views
Reply With Quote
  #2  
Old 09-05-2019, 07:59 PM
gregbradley's Avatar
gregbradley
Registered User

gregbradley is offline
 
Join Date: Feb 2006
Location: Sydney
Posts: 15,472
That's impressive. Its great that there are more tools now for polar alignment than before. It used to be a much harder thing to achieve a good polar alignment. Drift alignment is particularly tedious.

Greg.
Reply With Quote
  #3  
Old 09-05-2019, 08:03 PM
multiweb's Avatar
multiweb (Marc)
ze frogginator

multiweb is offline
 
Join Date: Oct 2007
Location: Hinchinbrook
Posts: 18,240
I still use my eyeball.
Reply With Quote
  #4  
Old 09-05-2019, 08:45 PM
AstroJunk's Avatar
AstroJunk (Jonathan)
Shadow Chaser

AstroJunk is offline
 
Join Date: Jan 2006
Location: Brisbane
Posts: 1,676
I love it. I don't even bother with the whole routine, I just use the cross-hair function with the initial platesolve and move the scope axes appropriately so that the SCP is dead center. I can track for hours with minimal drift after that.
Reply With Quote
  #5  
Old 12-05-2019, 09:18 AM
tvandoore (Tim)
Registered User

tvandoore is offline
 
Join Date: May 2016
Location: Buderim
Posts: 35
I use sharpcap polar align as well - great tool.

I have noticed that phd2's polar alignment analysis always shows that it is off by a bit, even after sharpcap says its spot on. I don't know which one to believe. I guess there's a chance they both could be correct, as we are talking different scopes and different cameras. But it's always annoyed me that perfect on one isn't perfect on the other, so I always feel that the alignment could be improved somehow.
Reply With Quote
  #6  
Old 12-05-2019, 09:37 PM
Icearcher's Avatar
Icearcher (Chris)
Registered User

Icearcher is offline
 
Join Date: Jan 2014
Location: Adelaide - Inner West
Posts: 141
Ill throw in a vote for Sharpcap PA, I love it.

Aligning my star adventure was a real pain before, took me over half an hour to drift align and it was still wasn't great.

Sharpcap has reduced that to a matter of minutes.

The only time I have had huge issues with sharpcap was when I was trying to get closer to PA in the first step, spent an hour trying to fix it until I realized I was aligning the guide scope to true south, not the mount, stupid move but a good learning experience.
Reply With Quote
  #7  
Old 13-05-2019, 09:46 PM
Fernando
Registered User

Fernando is offline
 
Join Date: Aug 2013
Location: Belo Horizonte, Brasil
Posts: 101
Hi there,


Where I am in Brasil, octans and the SCPole is kind of low. Sometimes, when is kind of cloudy or haze, Sharpcap may have some trouble find stars. Polemaster seems to me less demanding in this aspect. So, for sometime I have been doing like that: first Polemaster, followed by Sharpcap. It is a kind of routine to me. Do not ask why...


Regards, Fernando
Reply With Quote
  #8  
Old 18-05-2019, 08:06 PM
AstroJunk's Avatar
AstroJunk (Jonathan)
Shadow Chaser

AstroJunk is offline
 
Join Date: Jan 2006
Location: Brisbane
Posts: 1,676
A quick tweak tonight - That'll do nicely
Attached Thumbnails
Click for full-size image (Polar Align.jpg)
149.6 KB80 views
Reply With Quote
  #9  
Old 20-05-2019, 09:56 AM
Camelopardalis's Avatar
Camelopardalis (Dunk)
Drifting from the pole

Camelopardalis is offline
 
Join Date: Feb 2013
Location: Brisbane
Posts: 4,668
Quote:
Originally Posted by AstroJunk View Post
A quick tweak tonight - That'll do nicely
Looks miles off

It reckons youíre at 45 degrees south
Reply With Quote
  #10  
Old 21-05-2019, 08:13 PM
byronpaul's Avatar
byronpaul (Paul)
Registered User

byronpaul is offline
 
Join Date: Aug 2007
Location: Greenvale, Victoria, Australia
Posts: 361
Sharpcap Polar Aligment accuracy can be improved by using your real co-ordinates, and not the default 45deg North and South Hemisphere setting. Easy to configure in the settings.

Having already acquired a Polemaster, I was happy using that until Sharpcap came along, now I use the Polemaster Camera with Sharpcap software and itís just so easy to get excellent polar alignment.

Paul
Reply With Quote
  #11  
Old 21-05-2019, 10:02 PM
Hemi
Registered User

Hemi is online now
 
Join Date: Dec 2010
Location: Darwin
Posts: 268
Sharp Cap is a brilliant piece of software. I use it for live stacking. I wish the polar alignment routine could be modified to work when you don’t have a view of the pole.

H
Reply With Quote
  #12  
Old 22-05-2019, 06:55 AM
AstroJunk's Avatar
AstroJunk (Jonathan)
Shadow Chaser

AstroJunk is offline
 
Join Date: Jan 2006
Location: Brisbane
Posts: 1,676
Quote:
Originally Posted by byronpaul View Post
Sharpcap Polar Aligment accuracy can be improved by using your real co-ordinates, and not the default 45deg North and South Hemisphere setting. Easy to configure in the settings.
I have to admit to not having reconfigured my settings since changing my Observatory PC. It hasn't been an issue for me as I don't bother running through the routine anymore as the orthogonality of my system is pretty good and just by aligning as per the image, my drift is less than 5 arc mins over a couple of hours which is plenty good enough for my needs.

@Hemi - I also have PemPro (which I bought for the brilliant Meade handpad emulator it has). This was my former go-to polar alignment s/w and doesn't need to see the pole.

One thing I have learned since using the software - eqmod never parks the scope to the same point in the sky after a session I must see if I can fix that...
Reply With Quote
  #13  
Old 22-05-2019, 07:26 AM
Camelopardalis's Avatar
Camelopardalis (Dunk)
Drifting from the pole

Camelopardalis is offline
 
Join Date: Feb 2013
Location: Brisbane
Posts: 4,668
Quote:
Originally Posted by AstroJunk View Post
One thing I have learned since using the software - eqmod never parks the scope to the same point in the sky after a session I must see if I can fix that...
Iíve seen this before with AZ-EQ6 and EQ8s...try disabling the encoders...
Reply With Quote
  #14  
Old 31-05-2019, 11:11 AM
Howard's Avatar
Howard (Howard)
Registered User

Howard is offline
 
Join Date: Jun 2013
Location: Brisbane, Australia
Posts: 38
Quote:
Originally Posted by Hemi View Post
Sharp Cap is a brilliant piece of software. I use it for live stacking. I wish the polar alignment routine could be modified to work when you don’t have a view of the pole.

H
You do ... on your SW AZEQ6 the hand control has a built in polar alignment routine which does not need to use any stars near the pole in order to work. Just be sure to turn off the menu item which tells it to use the Advanced Filter, and to show alikgnment stars based on name ... so you can then do your alignment selecting your stars based on name. Once you have done either a two star or three star alignment it opens up on the hand control menu the Polar Align option. It does not take long to do.

On your star adventurer if you cannot see the polar region to use the SharpCap PA function then you are stuck with drift alignment as the way to go. Check out Google for the DARV Drift Aligning Robert Vice method as another way to drift align.
Cheers
Reply With Quote
  #15  
Old 31-05-2019, 03:57 PM
Startrek (Martin)
Registered User

Startrek is offline
 
Join Date: Dec 2017
Location: Sydney
Posts: 1,623
I have no view of the SCP at both imaging sites and have been solely using the Skywatcher Synscan Polar Alignment Routine on my HEQ5 and EQ6-R for a couple of years now with great success ( much quicker than drift )
Normally takes 15 to 20 minutes to get down to < 15 arc sec error ( 2 to 4 iterations ) I only use a 2 star alignment close to the SCP and alternate each star for PA ( eg Hadar and Acrux as they are in close proximity ) if I use stars far apart in azimuth ( say 60 to 70 deg ) I can be all night trying to get the PA error down as your chasing your tail
Once your PA is done you can do another 2 star alignment with stars further apart for more Goto accuracy
Thereís only one catch though , I now use BYEOS ( PA align target )with my DSLR to centre the stars with the hand controller , prior to that I used an Orion 20mm 70 deg illuminated reticle eye piece to centre which still worked well. No more stiff necks now as I just sit at my Laptop and complete my Synscan PA routine in comfort and with more control
Another hint is to de focus your stars into a small donut and centre them that way , itís far more accurate
Cheers
Attached Thumbnails
Click for full-size image (2A39E635-0730-44CB-A6C7-47A785E1C9D4.jpg)
175.0 KB10 views
Reply With Quote
  #16  
Old 31-05-2019, 07:42 PM
Howard's Avatar
Howard (Howard)
Registered User

Howard is offline
 
Join Date: Jun 2013
Location: Brisbane, Australia
Posts: 38
Quote:
Originally Posted by Startrek View Post
No more stiff necks now as I just sit at my Laptop and complete my Synscan PA routine in comfort and with more control
Another hint is to de focus your stars into a small donut and centre them that way , it’s far more accurate
Cheers
We think alike Startrek ... ditto pretty much to all your comments. I use EOS Utilities Liveview, and AstroToaster for imaging/VA/EAA (I "observe" with camera rather than EPs).

To continue in helping the OP re PA without seeing the pole ... there is also the iterative PA procedure which I've done a few times. Pick any star lying on 0 degrees DEC (ie the equatorial line) and use the HC SYNC feature to centre that star (think it's called PAE in the menu). Then slew to any star on the same side of the meridian closer towards the pole and note how far off centre it is. You adjust out half the error using the ALT and AZ bolts. Then repeat slewing back to the first equatorial star, SYNC, then back to the second star to note how far off it is, halve the error using ALT, AZ bolts. And so on.
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 11:44 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Advertisement
Meade Australia
Advertisement
Astromechanics
Advertisement
Bintel
Advertisement
Lunatico Astronomical
Advertisement
SkyWatcher Australia
Advertisement
OzScopes Authorised Dealer
Advertisement
Celestron Australia
Advertisement
Astronomy and Electronics Centre
Advertisement