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INDI Library v1.9.2 Released (14 Sep 2021)

Bimonthly Stable INDI Library release introduces new drivers and fixes for existing ones.

Polar alignment... what am I missing

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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
2 years 1 month 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.
INDI/KStars on Raspberry Pi 4, 4gb
Raspbian Buster with AstroPi3 script configuration
Skywatcher HEQ5 Pro Mount
Canon 600D Camera
Orion SSAG/ASI120mm @280mm Guide Scope
PHD2
Waveshare Stepper Motor Board - DIY Focuser
Adafruit GPS Module
Generic Bluetooth Joystick.
Startech 7 port powered USB Hub.
The following user(s) said Thank You: Jasem Mutlaq
2 years 1 month 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: 2 years 3 weeks ago by Yannic Delisle.
2 years 3 weeks 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
2 years 3 weeks 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
Wouter van Reeven

ASI6200MM and 7 slot 2" filter wheel with a SkyWatcher Esprit 80 ED on a SkyWatcher HEQ5-Pro
ASI1600MM-Pro Cooled and 5 slot 1.25" filter wheel with an 8" TS Ritchey-Chrétien on a SkyWatcher EQ6-R
2 years 3 weeks ago #43535

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Good to know !

I was about to move the star in the middle of the crosshair and remembered that having too perfect of a PA was not recommended (something with natural dithering I think?) I will dig a bit more on the subject ;)

Just to say that the process, when starting not to far from the NPC is quite easy and can achieve perfect PA in minutes... I am grateful that this is now part of Ekos :) I just needed some practice and field experience to enjoy the full beauty of it :)
"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
2 years 3 weeks ago #43538

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FYI Ekos can dither for you as well. In the guide tab, click on the Options button to the lower right of the tab and there you can configure this.
Wouter van Reeven

ASI6200MM and 7 slot 2" filter wheel with a SkyWatcher Esprit 80 ED on a SkyWatcher HEQ5-Pro
ASI1600MM-Pro Cooled and 5 slot 1.25" filter wheel with an 8" TS Ritchey-Chrétien on a SkyWatcher EQ6-R
The following user(s) said Thank You: Yannic Delisle
2 years 3 weeks ago #43540

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I am also a grateful user for the last month of the Ekos Polar Alignment routine, and with my portable setup, have naturally been beginning each session with It. I own a SW AZ-EQ5 which as purchased did not have a polarscope, so I locate Polaris in the finderscope, use it to focus my scope with a Bahtinov mask, and then place it in the finderscope somewhere near where I expect it to be from my experiences from earlier PAs.

I am imaging with a Canon DSLR on an 80mm refractor with focal reducer/field flattened, so the adjustment feedback loop from image capture to display is quite long at ~6 to 10 seconds. If I attempt too large an adjustment between preview images, I can lose the reference star off the screen, but sometimes realise it is actually hidden behind the purple adjustment vector.

Might it be possible for the vector to be set to be 50% transparent so that the reference star would shine through?

In making the final adjustments I place the reference star just under the end of the purple vector where, of course, it remains hidden. Is this right or should the star be placed just visible at the end?

When I run the PA routine again to check the new position, I am satisfied if it measures within 30 arcseconds or so.

[Edit] Note: I just read again the whole of this thread and it seems I am not seeing the ‘crosshair’ on the end of the correction vector. I am running the software on my Raspberry Pi 4 in headless WiFi hotspot mode and controlling it from an iPad using VNC Viewer. I zoom in on the iPad image (two fingers spreading out) to enlarge the adjustment screen. Perhaps this is where the crosshair is being lost? Is there a way of making the adjustment screen ‘full screen’ on the RPi during this adjustment?
Currently running KStars/Ekos/Indi on two Raspberry Pi 4Bs 4GByte under Raspberry Pi OS thanks to Astroberry
Two mounts, two Fracs, a Newt and a Mak and a couple of OSC cameras.
Last edit: 2 years 2 weeks ago by Avocette. Reason: Additional thoughts
2 years 2 weeks ago #43859

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I enjoy using the paa as well. It took a while to get my procedure down but now I can do it pretty quickly. It sounds like you may be putting the star at the wrong end of the vector. When you are prompted to choose a star the red cross hair should show up, it has a circle in the middle and that is where you should position the star, not sure why you are not seeing it, maybe like you said it is zoomed in, or out too far. After I choose my star I click next, then refresh, then in the upper left hand corner, default zoom, that usually gives a close in look at the vector with cross hair. On my Galaxy tab 8 tablet I have to move the vertical and horizontal sliders around to get the vector and crosshair in the middle of the screen., sometimes it is not visible at all at first and I need to locate it with the sliders then zoom in with two fingers to get a close view, then do the mount adjustments.
Greg, a user here has made a paa video that might be helpful. Skip to the end to see the red crosshair and you might get some ideas there to help you out


Good luck!
-Brian

NanoPC-T4 - Armbian focal
iOptron CEM25P mount
Photoline 80mm triplet refractor
ZWO ASI294MC Pro Imaging camera
ZWO ASI290MM mini Guide camera
ZWO ASI EAF focuser

The following user(s) said Thank You: Avocette
2 years 2 weeks ago #43860

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Thanks for this - it’s helpful to see someone using the same software, even if on somewhat different hardware, and as you suggest, I spotted a couple of things I will try next time I am out in the dark!
Ed
Currently running KStars/Ekos/Indi on two Raspberry Pi 4Bs 4GByte under Raspberry Pi OS thanks to Astroberry
Two mounts, two Fracs, a Newt and a Mak and a couple of OSC cameras.
2 years 2 weeks ago #43862

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There is a button to expand the image to full screen in EKOS. It has a square shaped icon.
INDI/KStars on Raspberry Pi 4, 4gb
Raspbian Buster with AstroPi3 script configuration
Skywatcher HEQ5 Pro Mount
Canon 600D Camera
Orion SSAG/ASI120mm @280mm Guide Scope
PHD2
Waveshare Stepper Motor Board - DIY Focuser
Adafruit GPS Module
Generic Bluetooth Joystick.
Startech 7 port powered USB Hub.
The following user(s) said Thank You: Avocette
2 years 2 weeks ago #43877

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Just tried again last night, this time with my Raspberry Pi 4 instead of my Mac. Did a rough polar alignment, forgot to level my tripod etc and then ran the Ekos Polar alignment tool. This time no problems, the crosshair was very close to my selected star and only very small adjustments needed to center the star. I haven’t changed anything in my setup besides changing from Mac to RP4. I’m happy.
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
2 years 1 week ago #44145

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