Polar Alignment with Star Adventurer 2 w/o Polaris in sight for DSO Imaging

Hi Nick,

I was using Astroberry for a while, but polar alignment was not my main concern back in those days. So basically I have no experience with KStars/Ekos in that matter. But I am using Nina and there is a plugin called 3-point-polar-alignment. Its not that this helps you, but there are some concepts, that should be used by other tools too.

As far as I know, there was a Beta version of KStars available, that should have one of those functions built in. I don't know, if the feature is released, yet. But if so, try to look at this function, too. But I can't tell you where to look for. I read about it in some forum posts and people seem to like it.

I tried to use PHD2 drift alignment 2 or 3 times. It worked quite good, but as you mentioned, pointing the scope to different parts of the sky was a bit time consuming and not as intuitive. But it is neccessary to get the data the function needs.

NINAs 3-point-polar-alignment would be a great solution for you. It works well with mounts with only one motor for the RA. The DEC axis motor is not needed here. You have to align your mount roughly to the pol, which can be done by the pol finder scope of the SA. Then it rotates the scope in the RA axis and takes three images of the same portion of the sky, but with a different view angle. With the data of those 3 images, it calculates the error and shows a live view while it tells you what to correct on your axis. This is a really simple concept and it can be done even with mounts without any motors (short: "fully manual" :kiss. Its a great idea to use such an algorithm. And it is so easy to use…

As far as I know, a similar solution exists also in SharpCap (was there even before NINAs implementation). I saw a lot of effort in other software, too over the last years and progress is quite fast these days. I think similar algorithms should also be implemented or will soon be implemented in other software. So you are not depending on PHD2 alone. Using Linux as OS and the Raspberry is a bit limiting, but there should be solutions out there.

Sorry, if I am not able to help you any further here. I found my preferred solution and use it since then. But maybe you get some hints that helps you somehow. It's just my two cents…

CS

Christian

This video might be useful https://www.youtube.com/watch?v=X2jagTiDZ6k&t=821s
I use PS Align Pro on a regular basis and you can get good polar alignment without Polaris. But you won't get as precise of course and you should reduce the exposure time to be on the safe side (you want  to avoid drifts inside a single picture - drifts between pictures is less of an issue if you frame wide enough to crop afterwards)

CS
Pablo

I'm imaging with a mobile setup which I have to carry into the field every evening. The "daylight mode" of PS Align Pro App is very useful for the initial setup to make sure the celestial pole is in the fov for later more precise polar alignment once the stars come out. The video shows very nicely what you can expect from the app. Of course not using the geographic north instead of the magnetic north is a big mistake. The magnetic inclination is 3 degrees in my location and can be even more depending where you are located. It's a simple change of setting in the mobile phone. Still, even with the proper setting you shouldn't expect too much from the app, but it's worth the money for people with mobile rigs to get a good starting point.

Clear skies
Wolfgang

Christian Großmann:
Hi Nick,

I was using Astroberry for a while, but polar alignment was not my main concern back in those days. So basically I have no experience with KStars/Ekos in that matter. But I am using Nina and there is a plugin called 3-point-polar-alignment. Its not that this helps you, but there are some concepts, that should be used by other tools too.

As far as I know, there was a Beta version of KStars available, that should have one of those functions built in. I don't know, if the feature is released, yet. But if so, try to look at this function, too. But I can't tell you where to look for. I read about it in some forum posts and people seem to like it.

I tried to use PHD2 drift alignment 2 or 3 times. It worked quite good, but as you mentioned, pointing the scope to different parts of the sky was a bit time consuming and not as intuitive. But it is neccessary to get the data the function needs.

NINAs 3-point-polar-alignment would be a great solution for you. It works well with mounts with only one motor for the RA. The DEC axis motor is not needed here. You have to align your mount roughly to the pol, which can be done by the pol finder scope of the SA. Then it rotates the scope in the RA axis and takes three images of the same portion of the sky, but with a different view angle. With the data of those 3 images, it calculates the error and shows a live view while it tells you what to correct on your axis. This is a really simple concept and it can be done even with mounts without any motors (short: "fully manual" ). Its a great idea to use such an algorithm. And it is so easy to use...

As far as I know, a similar solution exists also in SharpCap (was there even before NINAs implementation). I saw a lot of effort in other software, too over the last years and progress is quite fast these days. I think similar algorithms should also be implemented or will soon be implemented in other software. So you are not depending on PHD2 alone. Using Linux as OS and the Raspberry is a bit limiting, but there should be solutions out there.

Sorry, if I am not able to help you any further here. I found my preferred solution and use it since then. But maybe you get some hints that helps you somehow. It's just my two cents...

CS

Christian

Thank you Christian! I am going to try PHD2 Drift Alignment and EKOS Polar Alignment feature and see which one works for me better.

Just released: How to Polar Align When You Can't See Polaris!? - YouTube

Once again, this is all very rough but it should give you a good starting point for any more accurate method - whether you see Polaris or not.

Clear skies
Wolfgang

I have the PS align Pro app but never used it during the day. Will give it a try. I have seen the first video, will take a look at this one. Thank you for sharing!