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

Bi-monthly release with minor bug fixes and improvements

Polar alignment... what am I missing

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That is interesting. Would that mean when I was only clicking once it was showing the crosshair on the other end of the purple line but I could not see it as it was off screen ? If so, what is the purpose of bringing the crosshair to the other side of the purple line when clicking twice ? As you can see in the screen shot I was centered in that crosshair but the alignment is out by 1° ... This is odd
"Some people are so poor, all they have is money"
SW Black Diamond 80ED | SW150MAK | Newton SW 200/1000 | Orion 50mm Guider with Helical Focuser |Sirius EQ-G Rowan Belt Mode
Canon 1000D moded | ZWO ASI185MC | Baader Mark III Zoom
INDI | Stellarmate on RPI3B+ | Stellarium | Pixinsight
4 years 6 months ago #42897

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All the times I've tried to PA I could only see the Purple line across the entire FOV. When moving as far as possible along the line and then redoing the PA to get even closer, I was told be Ekos that the NCP was outside my FOV, eventhough I should've been closer than my initial PA. When the weather clears (should be within the next decade or so :) ) I'll give it a try again and double clicking this time (I've moved from running KStars/Ekos on my Mac to running it on a Raspberry Pi 4, but haven't had a chance to test it yet).

I think we need some of the developers to look at the thread. Maybe they can tells us about the double click etc.

Anders
SkyWatcher ED80 Pro
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ZWO ASI294MC Pro imaging camera
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4 years 6 months ago #42900

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There are reasons why the ncp will not be in frame and it is not the be-all-end-all. It could just be cone error, or slight Dec misalignment from when you setup the home position.
If was you day is true and double click moves the crosshair, it could be for those in the southern hemisphere.
I've only ever clicked once, and brought the star to the end of the line where my crosshair is.
4 years 6 months ago #42906

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so double clicking in any FITS viewer image would center the crosshair around that point. I just added code to disable this when polar aligning to prevent confusion. Should be in 3.3.5
4 years 6 months ago #42908

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So just to make sure I understand:

I could not see the crosshair because I was way out of range ( the 1° error was accurate then) it was actually at the other end of the purple line (?) Just moving along the line should show me the crosshair and then, once I see it, I just click once on a star near that crosshair and center it into the crosshair ?
"Some people are so poor, all they have is money"
SW Black Diamond 80ED | SW150MAK | Newton SW 200/1000 | Orion 50mm Guider with Helical Focuser |Sirius EQ-G Rowan Belt Mode
Canon 1000D moded | ZWO ASI185MC | Baader Mark III Zoom
INDI | Stellarmate on RPI3B+ | Stellarium | Pixinsight
4 years 6 months ago #42910

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If you can not fit the line in your FOV, you will have to do it more than once gradually reducing the error.
You will be clicking on a suitable reference star. It should be bright enough to easily distinguish while in the image refresh step. If you begin the refresh cycle and can not clearly see your chosen star, either increase the exposure time or select a new star. Do not select a new star once you've begun making adjustments. While refreshing, adjust your Alt/Az bolts and follow the reference star and attempt to bring it to the end of the line where the crosshair resides.
The following user(s) said Thank You: Yannic Delisle
4 years 6 months ago #42925

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Stupid question here, but are you pressing 'Next' *after* you've selected your alignment star in your second screenshot?

I've only ever used a single click in this stage to select a star.

After you've pressed 'Next' the PAA brings up a different panel (which you haven't shown a screenshot of) in which you can tell the guide camera to loop while you adjust the altaz bolts to bring the star to the crosshairs, so you can monitor in realtime (albeit with a slight lag) your progress towards the crosshairs.
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4 years 6 months ago #43016

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Hello,

Yes, I did follow the steps. My issue is that I am so far away from the NCP that it is not in the FOV where the crosshair might already be but I cannot see it. Double clicking center the crosshair on the star I double click on, so even after proceeding with the alignment on this new star, I am of course way out of wack (1°+) .

So, as per Jasem comment "double clicking in any FITS viewer image would center the crosshair around that point. I just added code to disable this when polar aligning to prevent confusion. Should be in 3.3.5"
"Some people are so poor, all they have is money"
SW Black Diamond 80ED | SW150MAK | Newton SW 200/1000 | Orion 50mm Guider with Helical Focuser |Sirius EQ-G Rowan Belt Mode
Canon 1000D moded | ZWO ASI185MC | Baader Mark III Zoom
INDI | Stellarmate on RPI3B+ | Stellarium | Pixinsight
4 years 6 months ago #43102

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The crosshair does not terminate at the NCP. Indeed, NCP does not even have to be visible. It is merely a vector representing the magnitude of your error. Click once to choose any suitably bright star you like and begin from there, moving that reference star in the direction of the vector. If the error is large you may not fit the entire vector in the frame, even if you choose a star far on the opposite side of the frame. In that case, correct as much as possible and repeat the process from the beginning. The crosshair is your goal, do not worry about double clicking anything to generate one over your reference star.
The following user(s) said Thank You: Jasem Mutlaq
4 years 6 months ago #43120

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Quick update on this. I got the chance to go out last night and was able to test this.

On the first try I was 6° out (!!) and had a hard time getting closer and closer just using my screen but I wanted badly to avoid using the polar scope and see if I could manage using only the PA routine. After a couple of tries, getting closer each time, lo and behold, the crosshair appeared in the field of view. I was able to refine the PA and stopped doing the PA routine when I reached 55'' ... not sure if I should have tried getting closer to 0'' I hear that it can be good to not be perfectly aligned when doing astrophotography.

I realized that it is much easier when you are close to the NCP from the start and can see the other side of the vector ;)

In summary, being close to the NCP helps a lot. It is challenging when you are in the field on a portable setup to be closely aligned on the first try so I guess I will still use the polarscope just to put polaris in the FOV and then do the routine to achieve perfect PA.

"Some people are so poor, all they have is money"
SW Black Diamond 80ED | SW150MAK | Newton SW 200/1000 | Orion 50mm Guider with Helical Focuser |Sirius EQ-G Rowan Belt Mode
Canon 1000D moded | ZWO ASI185MC | Baader Mark III Zoom
INDI | Stellarmate on RPI3B+ | Stellarium | Pixinsight
Last edit: 4 years 6 months ago by Yannic Delisle.
4 years 6 months ago #43523
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That's great.
I can't wait to give this a try again in the (hopefully) near future.
SkyWatcher ED80 Pro
Skywatcher HEQ5 Pro with Rowan Belt Mod with EQDIR cable
ZWO ASI294MC Pro imaging camera
QHY5L-II-C guide camera on 50mm guidescope
DeepSkyDad AF3 autofocuser
Raspberry Pi 4 4GB running Kstars/Ekos
4 years 6 months ago #43525

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Good job! 55" is pretty good. I once got as close as 12" and others have reported even better PA. But with subs of up to 20 minutes I haven't seen any noticeable field rotation or other guide errors when being around 1' = 60" off.


Wouter
4 years 6 months ago #43535

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