When the pink line is longer than your FOV and it runs off your screen you can do two things:
- do a crude correction of the polar alignment by literally picking up the mount and aiming it better at the pole
- use the fine adjustment of the mount and place the star at the side where the line runs out of the FOV and restart the polar alignment

When using the fine adjustment you may or may not run out of play depending on how big the polar alignment error is which means you will need to pick up the mount and free up play for the fine adjustment. Also, you may need to repeat the polar alignment procedure more than once to reach a very small alignment error.


HTH, Wouter

Thanks, I think that is what I tried doing and eventually got closer. But what seemed strange was that besides the correction vector there was a large arc (part of a circle) also indicated on the screen and it did not look like the correction vector was headed toward the center of that circle. So I am not sure what that circle represented. At one point ( and here my memory fails me just when) there was a celestial coordinate system overlap on one of my images (may have been during just a solve and sync); that might be nice to have during the polar alignment.

This is really the first time I have gotten this far into this process. I have been using KSTARS for a few years and, in the past, my scope setup has been a long process as I would start from all the equipment stored in the house; so I would have to take it all outside and put it together. Therefore, my polar alignment would be quick and dirty (did not want to spend more time on it) and my imaging sessions short. But I recently built myself a scope buggy with large wheels, so now I can keep everything setup in the garage and just wheel the assembled equipment outside; it is a big step forward towards using it more often and longer. So i am spending more time on polar alignment.

thanks again for all the work on this software.

What mount do you have and does it have a polar scope? If yes then why not use that for an initial crude polar alignment? That works really well and should get you within, say, one or two degrees of the celestial pole. There are several tools available that can help you do that. KStars have a tool for this hidden away in some menu item and there are several apps for this both in the Apple and Android stores.

As for the grid: that is the equatorial coordinate grid with the center at the celestial pole. The pink line should not point to it because that indicates the offset of your mount w.r.t. the perfect alignment. Also, the center of that grid generally does not sit at the center of the FOV when your telescope is parked due to minor positional offsets of the telescope w.r.t. the zero positions of the mount. Just ignore the grid and focus on the pink line. That’s all that matters when doing a polar alignment.

thanks again,
I have a Celestron CGEM mount and it has a location for a polar scope (a hole thru the mount), but I don't have any optics there. I was thinking of putting a bright laser pointer in that location. What I have tried is using StarWalk in my phone; mount the phone to the front of the scope and aim the phone display at the South Celestial Pole. I will come up with some method to get me closer to start with. The EKOS process did not take long, so I did not mind doing it a few times.

Where do I look to find a better explanation (more complete perhaps) of the settings for the FITS viewer. I was happy to find the auto stretch option, but there are other options that I am not sure I understand.
Also, I saw in one of the video's that you can use the "Main" Page to display a bigger view of whatever module you are in (focus or polar align). It would be useful to have a location in the forum for all the hints, suggestions and existing useful options (that are a bit hidden) in KSTARS and EKOS. The videos were great, but it would be nice to have a spreadsheet checklist for program setup. If there is not one already here (I have not looked - yet) , maybe I will make one.

thanks,
Ron

Ah yes, polar aligning in the south is harder for lack of a bright star near the south celestial pole. Sigma Octantis may work but is just too far off. I know since I moved to Chile recently and have had considerable trouble doing an initial rough alignment.

Perhaps collect your questions that are not related to focusing and polar alignment in a different topic?

Sorry, I confused you. I am in the northern Hemisphere, but when I set the phone up against the face of the Celestron 5" SCT you have to align to the Southern Pole if you want to look at the Screen (LOL). Yes, I can start another thread for other questions and will try to keep on topic here with further focus or polar alignment questions.

thanks,
Ron

More stars and more progress tonight. After several attempts I finally mounted a bright green laser pointer to the mount so it was aligned along the mount axis. Pointing it at Polaris put me in the ballpark. I finally saw a correction line with a cross hair at the end of it and was able to move the bright star into the cross hair (the star turned out to be Polaris, my field of view is 55 by 70 arcminutes, so I think that makes sense. It took me four polar alignment attempts tonight to get to that point but in the end it was satisfying.

Now for a couple of issues: the scope does not seem to move the set degrees in the polar alignment routine. I would set it for 15 or 30 degrees, but it did not seem to make a difference it only moved a small amount. Is that 15 degrees or 15 minutes?? It did respond to 'East' and 'West' correctly, but the amount of rotation did not seem to agree with what I set.

One time it tried to move 90 degrees and I tried to stop the process, but I never could. Then I realized I had put Kstars and EKOS in different desktops. the response to stop the process was on the Kstars desktop, while the process was on the EKOS desktop. This does not make sense, if it s going to ask to you do really want to stop polar alignment that question should be in the same desktop as the process. Maybe it is a matter of which one is on Desktop 1 and which one is on Desktop 2, but it so it should be spelled out somewhere.

When I did sync and solve there would be numbers (sometimes big numbers) in the 'ERR' box. What do those mean? and if there is a difference between what the sky says I am pointing at and what the scope says its pointing at, how do you correct that?

I tried using Kstars to slew the scope to several different open clusters and I found that I needed to move the scope to the target, do a solve to find out that it was not on the target and then go back to Kstars to move it there again. I think it is a reasonable process to move, check where you are and then do a closer move. I would like to understand if and how to make corrections in pointing the mount, if you can point me to something to follow up on that it would be helpful.

All in all, things are working. Naturally, as I finally got to some interesting targets, the clouds moved in, so I had to stop.

thanks,
Ron

For the movement in Ra being inconsistent I think this is because when you are close to the pole Ra is a very poor measure. It would be better for the software to be aware of the movement rate in degrees per second and use a timer to do the move. As a user, set the manual move option and move by hand the amount you want.

Adding to what Chris wrote re manual mode: make sure that the slew speed is set correctly for your mount if you want to use the automatic mode. I have a SkyWatcher HEQ5-Pro and need to set it to 800x for it to work properly. The default is 64x which works but it takes forever (or so it seems) to rotate 30 degrees.

As for having KStars and Ekos in different desktops: did you do that yourself? I have never tried that but I did try to use Ekos "in a separate window" mode and also noticed that all modal popups showed up in the KStars window. That's when I stopped using Ekos in a separate window and simply got used to opening and closing it when I need it. Perhaps opening a new topic for this if you want this fixed would be a good idea.

As for the big ERR numbers: Chris already addressed this. Ekos expects the mount to be pointed at the north pole with the RA equal to the current sidereal time (i.e. the RA culminating) and close to the pole RA is a very poor measure (to quote Chris because it is too early for me to think of another way to phrase this). The ERR boxes display the differences in RA and DEC expressed in arc seconds which very quickly become very large, especially if plate solving shows that the mount is pointed to a too low altitude (essentially giving an RA +/- 12h wrt the current sidereal time).

When using Ekos in slew mode, swithc from the Polar Alignment tab to the Solutions Result tab (to see the alignment process working) and make sure to tick the "Slew to Target" checkbox. That way, Ekos will send a correction to the mount which then should slew to the target. It will then perform another plate solve to measure the new alignment error and will send corrections again. In general it should take a few iterations to reach the target, depending on the "Accuracy" (expressed in arc sec) among other things. Be patient with this the first time you try in a night and consecutive slews should go increasingly quicker.


Clear skies, Wouter

Great Responses, thank you that explains a lot. I will go with the Manual approach. Can I use the celestron CGEM hand controller to move the mount or do I NEED to use the mount motion buttons in the INDI Manager? It seems if I use the CGEM hand controller that upsets the coordination between the program and the mount. For example, if I set the "HOME" postion on the hand controller it is not in the same position once I run EKOS (whether I set the park function or not). So just asking if in the polar alignment routine when you do Manual motion does the program check the new position of the scope before it does the capture and solve or does it assume the motion was done thru the program?

Yes, I checked, in Kstars Config, to have EKOS start in a separate window and moved Kstars to a different desktop. That is when the pop up windows come up always in the Kstars desktop. I will start a separate thread on this topic under "wish list". If you don't have them in separate windows then EKOS is always on top of Kstars and you have to move it to see the planetarium view (if you are using that to slew the scope). So it is more convenient to have them in different windows and just open one or the other. But I think the pop up windows should come up with EKOS.

thanks.
Ron

AFAIK using the hand controller to move the mount should work. Park/Home position is a different thing. However, I do not own a Celestron mount so please simply try it out and see for yourself.

Yes, you can use the hand control buttons. On the Celestron if you press one button, then press the opposite one as well you get a full speed slew.

As for the Celestron Home and INDI Park I would like to make them the same. The control for this exists in the protocol for the current HCs. One snag is that the INDI park handling is embedded into the base part of the driver and it may be difficult to extract it without upsetting everyone else.