Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Using SharpCap Pro to better polar align an EQ platform

  • Please log in to reply
6 replies to this topic

#1 Borodog

Borodog

    Apollo

  • -----
  • topic starter
  • Posts: 1,323
  • Joined: 26 Oct 2020

Posted 27 January 2021 - 06:09 PM

Has anyone tried it? Ideally you want to rotate about your RA axis by 90°, but I know it works just fine down to at least 45°. However, an EQ platform probably has at most 15° of travel about its axis. I think that should provide enough accuracy to at least get alignment much better than otherwise, but I'm not sure if SharpCap will even attempt it. Has anybody tried it?

 

Regardless, I'll give it a shot the next night I can and report back.



#2 alphatripleplus

alphatripleplus

    World Controller

  • *****
  • Moderators
  • Posts: 120,636
  • Joined: 09 Mar 2012
  • Loc: Georgia

Posted 27 January 2021 - 06:23 PM

Never tried it with an EQ platform, but from my experiences with SharpCap's PA routine on a GEM I don't think 15° of travel is going to be nearly enough for SharpCap to work its magic. I would love to be proven wrong though.


  • ButterFly and Borodog like this

#3 Borodog

Borodog

    Apollo

  • -----
  • topic starter
  • Posts: 1,323
  • Joined: 26 Oct 2020

Posted 27 January 2021 - 06:42 PM

Never tried it with an EQ platform, but from my experiences with SharpCap's PA routine on a GEM I don't think 15° of travel is going to be nearly enough for SharpCap to work its magic. I would love to be proven wrong though.

My hope is that by getting stars in the solve that "circumnavigate" the NCP, if you understand my meaning, that 15° will be enough, but we shall see. I think worst case scenario is that I can do it manually. SharpCap will definitely be able to get a solve, and then I can rotate during a long exposure and see where my center of rotation is and move that at least closer to the NCP than I otherwise would be able to, even if SharpCap can't do the magic, as you say.



#4 ButterFly

ButterFly

    Surveyor 1

  • *****
  • Posts: 1,690
  • Joined: 07 Sep 2018

Posted 27 January 2021 - 07:08 PM

SharpCap asks for more motion until it's enough, and only then continues with the PA routine.  It expects a motion on the order of ninety degrees - fifteen is too little for it to continue.

 

You can always just platesolve yourself.  Point to where you think north is, plate solve, move, then repeat until you meet you personal tolerance.


  • Dynan likes this

#5 Sacred Heart

Sacred Heart

    Viking 1

  • *****
  • Posts: 718
  • Joined: 16 Aug 2020

Posted 28 January 2021 - 12:24 AM

I tried it, with a 70 - 200MM F28 Canon lens with a QHY462 camera.

     

    #1 It was a bear to focus, lost alot of time there.

 

     #2  adjusting the camera to take a suitable image, another hurdle,     Remember, I am using a camera lens.  72MM.

 

Once it got the first photo,  I was off and running.  Just follow directions on the screen.   I have a GEM,  started from the 9 o'clock position,  then rotated to 12 o'clock position.   After it took the second shot, I hit the next button, and started moving both axis manually til I got an excellent reading.  Numbers were bouncing around,  anywhere from zero to 24 arcseonds.

 

  I'm waiting for clear weather to go and verify how good it is.

 

     If I had a small refractor / guide scope and maybe a bigger imaging chip,  it probably would have been easier and quicker.   Took about 30 minutes to do what I did.       Joe



#6 SteveInNZ

SteveInNZ

    Viking 1

  • *****
  • Posts: 897
  • Joined: 07 Oct 2007
  • Loc: Auckland, New Zealand

Posted 28 January 2021 - 03:48 AM

At Step 1 of the Polar Alignment process is a checkbox to allow smaller rotation angles, specifically for Eq platforms.

 

Steve.


  • ButterFly likes this

#7 alphatripleplus

alphatripleplus

    World Controller

  • *****
  • Moderators
  • Posts: 120,636
  • Joined: 09 Mar 2012
  • Loc: Georgia

Posted 28 January 2021 - 09:49 AM

At Step 1 of the Polar Alignment process is a checkbox to allow smaller rotation angles, specifically for Eq platforms.

 

Steve.

Interesting -  I had not noticed that before in the instructions.




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics