Author Topic: Unable to find an initial set of putative star pair matches  (Read 1935 times)

Offline dchamberlain

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Hi,

I am not being successful in performing a Star Alignment with PixInSight. I don't understand why this is so difficult to do with this software, as I have had experience with others that worked very well.

I have 25 exposures from a Canon 6D (first, not Mark II). I am using the newest RAW format input process. When I get to StarAlignment, I am taking mostly defaults and changing values for star detection and star matching trying to find a combination that works. I continue to receive this message on all but 2 exposures: *** Error: Unable to find an initial set of putative star pair matches

There are plenty of stars in the image and I can't understand why it is failing to find any matches.

Dale

Offline wimvb

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Re: Unable to find an initial set of putative star pair matches
« Reply #1 on: 2018 May 29 13:24:23 »
Try adjusting the noise threshold and noise wavelet layers. This usually solves the problem.
Wim

AZ EQ6 GT + EQ3 PRO, SW 150P-DS, SW MN190, ZWO ASI174MM-Cool, Pentax K20D (retired),
SW ST80 + ZWO ASI120MM + Lin_guider

Offline John_Gill

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Re: Unable to find an initial set of putative star pair matches
« Reply #2 on: 2018 May 30 00:35:26 »
Hi,

Sometime when I have had this issue, I use the following settings:
Star Detection
 - Detection scales 3
 - Noise scales 0
 - Hot pixel removal 1
 - Noise reduction 5
 - Log sensitivity -1.00
 - Peak response 1.0
 - Maximum distortion 0.500
 - Upper limit 1.00

Star Matching
 - RANSAC tolerance 7.00

Look up
John
APM 107/700 apo on CGX mount
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... when there are no clouds ...

Offline wimvb

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Re: Unable to find an initial set of putative star pair matches
« Reply #3 on: 2018 May 30 01:00:52 »
Those are the parameters I actually meant. I wasn't at my computer yesterday to look them up.
For me, increasing detection scales, noise scales, hot pixel removal, and noise reduction all by 1, solved the problem. But anyway, just play around with these values until the process can align the subs.
To get better integration results, you can use subframeSelector to assign weight factors to the subs. This way, even half decent subs can make a contribution to the final result.
Wim

AZ EQ6 GT + EQ3 PRO, SW 150P-DS, SW MN190, ZWO ASI174MM-Cool, Pentax K20D (retired),
SW ST80 + ZWO ASI120MM + Lin_guider

Offline DavGold

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Re: Unable to find an initial set of putative star pair matches
« Reply #4 on: 2018 June 06 05:52:31 »
Are your images debayered?   In my experience, PI will not process a non-debayered DSLR file.

I shoot a D5300 and D610.   The order of my files is RAW - Calibrate - Debayer - Staralign - Integrate.

FWIW,

David
David