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INDI Library v2.0.6 is Released (02 Feb 2024)

Bi-monthly release with minor bug fixes and improvements

focus and Polar align "issues"

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Finally got a clear night with stars and starting a separate topic as suggested.

I have an SBIG 8300M not the most sensitive camera (and it is old), it would really help in both the focus and polar alignment modules if the previews could be stretched. If I am out of focus I have to use the fits viewer to get close , since I can auto stretch with it. It would be great to have that feature in the focus window.

Same with Polar align, but at least by that point I am in focus, but still stars are dim unless I increase the integration time.

Good News is that all my equipment is working and I was able to make a first attempt at polar alignment. I set the scope up with the rotation axis facing the pole (I don't have a pole scope in my CGEM mount). and began the process. the solves went pretty quickly, but when it came to slewing the mount it moved it all the way to my mount limits.

So questions are:
can we get auto stretch in focus and polar alignmnent preview windows?
Is there a place to set mount motion limits in EKOS (I looked in setup windows and did not see anything obvious)
The polar alignment slew is taking my mount from vertical all the way to 15 deg beyond horizontal (my limits) is that normal. It took forever, but I had it on a slow speed and it stopped at the limits set in the CGEM hand controller. I told it the motion was done and it took another image and solved and eventually gave me a correction vector, but it was mostly off the screen. At that point, I said enough for a night until I get a little more input.

thanks for your responses.

Ron
4 years 2 months ago #48095

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Real Progress, but with a few little mysteries. First I found out how to auto-stretch the preview windows. It is in Kstars-settings-configure-fits; just check the box!! That really helped with focus and alignment. Focus then went smooth and moved into Polar alignment. Tonight it was working fine. It would take the initial image, move the set amount (which was the 15 or 30 degrees; east or west) which I specified, take the remaining images ; solving all the way. I made sure the calculated FOV was what I thought it should be, was the only preparation for that (I used astrometry - offline). Now while the solves worked, I had trouble with the adjustment as I was far enough off that I never did see a cross hair to move a star to. I would see the adjustment line and I could pick a star and move it along that line, but I never seemed to get closer to the end. So I repeated the polar alignment process about 3 times, each time from an different adjustment point. Eventually, I worked closer to the pole, but it did not work the way I expected. I watched a couple of the early videos on 'First Light' and "polar Assistant", but they went by that part of the adjustment too quickly. I need more practice (time) with it.

After that I did a solve and synced the scope to it and was able to slew the telescope to various stars and objects using the Kstars Window.

Here is where there are a few mysteries. I could not move Kstars to another desktop (I have 2 on the RPi) without moving EKOS with it; unlike what I saw in the video. Also, I cannot get Kstars to show up on top of the EKOS window, no matter what I select in the window options (always on top, normal, always on bottom). EKOS was always on top of KSTARS planetarium view. The FOV indicator in Kstars display does not follow the telescope location, you have to move everything to it (seems a little strange) and sometimes a FOV would show up with the telescope location indicator, and sometimes not (it would be left behind somewhere). All minor points, but I just don't know if I have things set up correctly or am just missing to set something someplace.

Like I said it is a complicated program, but it seems to be functioning pretty well for me (at least tonight).
Well I spoke the proverbial "too soon" I captured around 30 images; darks and lights of one object and that schedule ran fine. I then started a second schedule and came in to write this up only to find that the second schedule stopped on a "failed to allocate memory" error. I will look into this and start another thread.

thanks,
Ron
4 years 2 months ago #48139

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Hi Ron,

Good to see you are making progress. A few replies:

- In the KStars configuration there is an Ekos section in which you can specify that Ekos should be in a separate window. Then you can have KStars and Ekos on separate displays
- There is a button in the KStars button bars that should sync the KStars center of FOV with the telescope. Did you tick that? If yes then it is probably lag on the network connection between the RPi and your laptop/desktop


HTH, Wouter
The following user(s) said Thank You: Ronald Scotti
Last edit: 4 years 2 months ago by Wouter van Reeven.
4 years 2 months ago #48140

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Thanks, that clears a few things up. I am hopeful that the unexpected shutdown of my second sequence was of my own doing. I was running the Astroberry Server from a Laptop in the garage. I have the Rpi connected by a long Ethernet cable to the router in the garage, both it and the laptop had wired connections. Then I came inside and from my study I opened a VNC connection to the Astroberry server over wifi. I do that with my Ipad when I need to make adjustments at the scope, but that is just a passive connection as I am only looking at the screen. When I opened up the VNC connection I saw that I could also make changes to the server from the computer upstairs and I think it was that conflict of commands that started shutting everything down.

At least that is what the logs seem to indicate, so maybe I don't have a memory allocation problem (I hope not).

I am also hopeful that my issues with the polar alignment process was because I was so far off of the pole (I think it said I was 3+ degrees off). Hopefully if I set the scope up more carefully I can start closer than that. I would still like to see a better explanation of what you need to do when you see the screen with the correction line running off the screen from a selected star.

thanks again,
Ron
4 years 2 months ago #48142

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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
4 years 2 months ago #48152

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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.
4 years 2 months ago #48158

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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.
4 years 2 months ago #48160

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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
4 years 2 months ago #48164

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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?
4 years 2 months ago #48165

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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
4 years 2 months ago #48166

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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
4 years 2 months ago #48204

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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.
4 years 2 months ago #48216

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