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INDI Library v1.8.5 Released (19 Apr 2020)

April 2020 release of INDI Library v1.8.5 introduces new drivers while providing fixes and improvements to existing devices and core framework.

Off-Centered - While Dithering

2 months 5 days ago
ChrisRowland
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Off-Centered - While Dithering #51471
A Log showing the initial align process, the flip and the align process after the flip is absolutely essential. Also raw fits images taken after both aligns. Details of when the various processes happened would help.

Vague anecdotes and screenshots are, I think, worse than useless. Worse because they waste time, encourage speculation and are frustrating for the people who would like to help.

If you expect people to spend their time going through this and working out what is going on then spending a little time to help them do so seems reasonable.

As for the DSS images it looks as if no flip was done because a flip will rotate the image by 180 degrees - well unless DSS has rotated one of the images back. If the flip failed I would still expect that an alignment would be done, but who knows. We don't.
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2 months 5 days ago
universalmaster
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Off-Centered - While Dithering #51479
Maybe the developers should considering enabling logging of everything pr. default, such that logs can always be provided?

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2 months 4 days ago
Megiddo
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Off-Centered - While Dithering #51482

ChrisRowland wrote: If you expect people to spend their time going through this and working out what is going on then spending a little time to help them do so seems reasonable.


I hear your frustration. And I don't blame you. But you might also think of the frustration of throwing out 14 images from 23. So I was a tad frustrated too.

But hey, this is a work in progress. I get it.
Also, knowing ahead of time (to turn on logs) when I don't expect failure is kinda tough too. But you know I will in the future! ;)

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2 months 4 days ago
Megiddo
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Off-Centered - While Dithering #51483

knro wrote: is <strong>Reset Mount Model After Meridian Flip</strong> check in Ekos Capture options? When using EQMod mount this could help.


I saw this on the other thread... I'll try to remember to check that off. I hear rumors... just rumors, that those sparkly things might be out tonight!

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2 months 4 days ago 2 months 4 days ago by Megiddo.
Megiddo
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Off-Centered - While Dithering #51495

knro wrote: is <strong>Reset Mount Model After Meridian Flip</strong> check in Ekos Capture options? When using EQMod mount this could help.


For those like me... ;) Who couldn't find it right-away.
Open Ekos / CCD Tab / Options Button / Ekos / Capture Tab / Reset Mount Model After Meridian Flip

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1 month 3 weeks ago
Megiddo
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Off-Centered - While Dithering #51825
I'm getting the feeling that what might be happening is... the random dithering that occurs, might be getting stuck in a downward trend?
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1 month 3 weeks ago
Ihoujin
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Off-Centered - While Dithering #51855
Cone error will manifest as a misalignment after a meridian flip. So you should always do a realignment, ideally with plate solving.

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
Adafruit Motor Hat shield
Adafruit GPS Module
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Startech 7 port powered USB Hub.

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1 month 3 weeks ago
Megiddo
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Off-Centered - While Dithering #51885

Ihoujin wrote: Cone error will manifest as a misalignment after a meridian flip. So you should always do a realignment, ideally with plate solving.


After a flip, it does re-align itself, but I don't think the issue is occurring after the flip for me... it might just be the random dithering is getting stuck in one direction.

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1 month 2 weeks ago
Megiddo
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Off-Centered - While Dithering #52030
I changed my dither to 1 pixel, but it did it again last night. Had to throw away about a dozen 4 minute images.

Unfortunately I had to get my rig in quickly at 3am as rain was minutes away. I woke up and gave my images a look-see on my phone and saw the Cigar Galaxy going lower and lower in the images.
I wish I had done the view in the FITS Viewer recent images tab, because you can see the target dithering and following one direction. You can see it in my previous post with the attached MP4 ( #51825 )

I wish I could change the title of this thread... it's not after the flip that is the issue. It a while after the flip.

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1 month 2 weeks ago
knro
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Off-Centered - While Dithering #52097
Thank you for the investigation David. The simple dither algorithm is implemented here

Perhaps there is a reason it's going in one direction, but the base math checks out unless I'm not accounting for vector math perhaps or even something more fundamental .. if you spot an issue, let me know!

Jasem Mutlaq
Support INDI & Ekos; Get StellarMate Astrophotography Gadget.
How to Submit Logs when you have problems?
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1 month 2 weeks ago
Megiddo
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Off-Centered - While Dithering #52234
Sorry it's taken so long, but I've been spoiled in the past by being able to walk through code watching the variable values.

Wondering why Random is used vs. a fixed direction? default_random_engine generator(seed); Can I see what value it might return?

Why not just do a Right/Down/Left/Up... in order? Or even Right/Right/Left/Left. Eliminating the possibility of a Down/Down/Down/Down.

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1 month 2 weeks ago
Megiddo
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Off-Centered - While Dithering #52340
Another bunch of photos lost to what looks like dithering in one direction. (only guessing on that)
Here is my log from last night.

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File Name: log.zip
File Size:688 KB
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