Hi All,

wondering if anyone can help tips to make things easier. I love the look of the Polar Alignment in Ekos but is it easy to do? I really struggled with it. I have a Celestron C5 with a 0.63 reducer and a Canon camera 450D on a Skywatcher EQM35. I appreciate the FOV is narrow but solving PA images are no problem and it does this and rotates the mount every time solves no issue.

My problem lies trying to get the star I choose in the target. No matter what polar alignment error I have I can't seem to make the star follow the line. So using 800 ISO or 1600 ISO on 5 second shutter speed I get to the point where I chose a star and calculate error option. I choose a bright star and it shows me the green/yellow/magenta triangle, but then as son as I press refresh on 2 seconds, for some reason the star i clicked on disappears and seems to show different star pattern on the next capture. If if i choose a big bright star (think i even selected Polaris once) as soon as I press refresh, the next capture comes and boom the star is gone. Could the mount be slightly moving from the moment of choosing a star to refresh the next capture? So at this point the star pattern as changed not to give up, I try to use another star in the FOV bearing in mind it is not on the corner of the triangle overlay anymore I could still sort of send it in the direction of the target roughly to get closer and retry the alignment process again in theory. Comes my next issue, even using another bright star i can't seem to follow it or make it move, it just seems to fall off the FOV, even if it tells me the direction to go say left 1 degree and up 1 degree, I don't even know which way right is on the adjustment knobs which way is left, I have a red dot finder So I have just been using that as a guide for right left up and down, sometimes it goes in the direction i want and sometimes it doesn't I'm just going off guesswork. I have managed to whittle the Polar alignment error to say 10 seconds on the declination and then maybe 30 seconds on the RA. and then I want just a little more which i try and then repeat the PA process again, then it goes to 4 degrees error, repeat the process now it's 7 degrees error, so i have completely gone the wrong way not knowing which direction is the right way. It took 4 hours last night to try and polar align and only stopping because my camera died because I was determined but I just packed up.

I know this all sounds really noobish, I just wonder if there is an easier way. is there some kind of live feed so it is easier to follow the star rather than 2 second refresh because things are changing too much on each refresh to follow easy.

Thanks for reading

Hi Tariq,

What version of Ekos/KStars are you using? The more recent versions have provided for using plate solving (rather than selecting a star). The mount moves between each of three frames to calculate your alignment error which has been the same for a while. EKOS then displays the triangle imagery and alignment error as it always has. But now, along with the alignment error you also get arrows to indicate in which direction you should adjust your mount to achieve polar alignment. This method still requires a refresh of images as you make adjustments and, depending on your camera settings, you can get the refresh rate down to 1 or 2 seconds. You simply adjust your alignment without picking a star and the error calculated via plate solving will update to show you progress toward alignment with no star selection required.

Let me know if I've missed something.

I’ve had similar problems with the image moving between the last rotate and my starting the refresh. Doesn’t always happen so I’ve not narrowed it down I’m afraid. I’ve noticed that sometimes I get a strange image (noticeable when doing flats and the first one is over exposed while the rest are fine or I have stars in my first dark frame at the end of a session) so possibly something is going wrong with it knowing which frame is which.

As to the direction of movement I had a problem where my computer clock was wrong and that seemed to cause all sorts of problems trying to polar align, might be worth checking that. I also tend to ignore the arrows ( really should note which change of my altitude/azimuth results in what change on the star map…) I just tweak one and see where the star moves. Sometimes things don’t seem to move quite consistently which I put down to slack in the screw threads.

I use a c6 with a reducer and a dslr so my fov etc shouldn’t be too dissimilar but as long as I don’t turn the knobs radically the stars tend to stay within the frame.

Might be worth trying the polar drift tool in phd2 if you have a guide scope.