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.


NINA - Slew to target not accurate

Astrophotography Imaging Software
  • Please log in to reply
29 replies to this topic

#26 Robert7980



  • -----
  • Posts: 3,556
  • Joined: 20 Nov 2022
  • Loc: Western North Carolina

Posted 26 September 2023 - 06:48 PM

Hi all,


Thanks for the reply, regarding this plate solving, I think I get a better understanding now. So next time once I am polar aligned (try to get down to around 30secs of total error), I will pick any location/stars/DSO that is within my visibility, "slew and center" in NINA, the first time it might not be correct but as long as NINA is able to plate solve, then it would be able to adjust the location until it locates the correct location of the object. Once this is done, the mount is considered as "synced". Is this correct?


And after that "synchronization", once I moved to a different object will it be more precise? Or this synchronization process will always have to be done every time we move to a new target?

Thank you.




Edit: As for the GSS location, I have tried to follow the location from my Stellarium (laptop) and SkySafari (mobile phone). I have set the latitude, longitude and elevaton following  the SkySafar though. I think that is all that needed for the location? I will check on that again in my next session.

No, you have to set the location in Green Swamp Server, that’s where the mount reference is, the time also has to be very precise… That is the only place it needs to be set, ASCOM will send that info to wherever it’s needed such as NINA…


Stellarium is just sending coordinates for the place in the sky the object is, that needs to be set as well for it to be accurate, but they are two separate things… 


So how it works is all objects have coordinates that don’t change, if they did you’d never be able to find anything… What GSS and the mount do is translate those object coordinates into live coordinates based on where the telescope is and what time of night it is… 


If you open GSS you’ll see a place to input the information under observatory location. This is how the mount knows where it is.. 


It will use this information along with the time of night to figure out where to point. It assumes your polar aligned and both axis are at the home position… The more precise all this is the better the goto will be, that includes having the mount level with good polar alignment… 


With plate-solving none of this matters as much, but for raw goto with just numbers then everything needs to be precise for it to work… Or it has to be 1-2 or 3 star aligned… Whatever the mount uses to get itself into a known position… 


Edited by Robert7980, 26 September 2023 - 07:09 PM.

  • DanMiller likes this

#27 Robert7980



  • -----
  • Posts: 3,556
  • Joined: 20 Nov 2022
  • Loc: Western North Carolina

Posted 26 September 2023 - 07:01 PM

I’ll add that if I understand what your trying to do then it’s not going to be easy, there’s a reason people have $20,000 mounts with encoders and spend a lot of time building a model for the mount to accomplish this task… Doing a raw goto slew is not something that I’d want to try often… 


I’d look over all the settings for sure, but then I’d put all my effort into getting patesolving in NINA setup, your life will be so much easier… Once that’s setup it really doesn’t matter how far off everything is (within reason) as long as it can see some stars then it’ll make the corrections to center your target exactly… 


The only time I use what your trying to do is for observing the sun during the day, when no other alignment is possible. My mount is simi-permanent though so it’s always polar aligned… 

Edited by Robert7980, 26 September 2023 - 07:03 PM.

#28 DanMiller



  • -----
  • Posts: 3,870
  • Joined: 20 Jun 2022
  • Loc: Pennsylvania, USA

Posted 26 September 2023 - 07:53 PM

Your using NINA, why make life hard.  Just have NINA do the goto.  If your doing visual, set it up that Stellarium does the goto.  

  • Sheridan likes this

#29 AriaA7



  • -----
  • Posts: 35
  • Joined: 28 Sep 2022
  • Loc: Columbus, OH, USA

Posted 26 September 2023 - 09:16 PM

I remember I had a similar ish issue first couple times, after a lot of searching I ended up realizing that I even though I verified my GPS coordinate numbers a dozen times, I missed the indicator for East/West. When I set it to W (where I'm located) instead of E (default?) in Ascom, everything worked perfectly.

Edited by AriaA7, 26 September 2023 - 09:16 PM.

  • DanMiller likes this

#30 NovaAstroFog


    Vostok 1

  • -----
  • Posts: 110
  • Joined: 17 Feb 2023

Posted 06 October 2023 - 04:43 PM

For what it is worth, if I am imaging a planet, I know I am polar aligned enough with my mount on a pier, I just manually point at a bright star and start tracking, so I can quickly collimate the Edge8. Then I use my finder scope again to find the planet, lock my clutches and start capture. I am normally shooting planets at f20 by adding a 2x Barlow, so plate solve or GoTo doesn't work anyway. They call it Lucky Imaging for a reason, no need to overthink it all.

Spectacular seeing is what you really need. You could get good images of Jupiter and Saturn holding your telescope on your shoulder like a grenade launcher if you took enough 2-3 minute videos at 250FPS with excellent seeing. 

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

Also tagged with one or more of these keywords: Astrophotography, Imaging, Software

Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics