Issue With Plate Solving

Pleiades Astrophoto PixInsight Plate Solving Help Needed
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Caleb Evans avatar
Caleb Evans avatar

I have been sitting on some subs targeting NGC 2903 for a couple of months now, and have not been able to edit them properly due to issues with my Image Solver script in PixInsight. For some reason, the field isn’t registering correctly with the correct coordinates. Is there a deeper issue here with my Gaia database not loading properly? I sent my subs to a friend and they were able to go through the Image Solver script with no hiccups. Attached are some screenshots from my workflow.

Any advice or help is appreciated! I feel stuck looking at this same issue for over two months now.

📷 Process Console 1.pngProcess Console 1.png📷 Process Console 2.pngProcess Console 2.png

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Marcin Cikała avatar
Marcin Cikała avatar

Hello.

The PI platesolve script can be very choosy. You can solve image without any problems in ASTAP/PlateSolve2 or 3, but you'll encounter problems in PI.

First of all you should try playing around with the star detectioin parameters in the Advanced Parameters tab. Besides the relatively correct initial parameters in Image Parameters tab ( especially Image Scale and Pixel Size, the initial R.A. Dec) the advanced settings are crucial for star detection. And IMHO your situation likely points to this issue.

GAIA is just a catalog with the coordinates of nearby stars. It has no impact on star detection or the formation of pairs/triangles. You can choose any other star catalog and get the same results.

Try to play.

Regards, Marcin.

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pfile avatar
pfile avatar

when this happens, usually the gaia database is misconfigured.

check this post:

https://pixinsight.com/forum/index.php?threads/issues-with-spfc-and-spcc-in-pixinsight-1-9-2.24867/page-2#post-163802

Jure Menart avatar
Jure Menart avatar

Agree with pfile!

It happened to me just recently. Image solving was always working but I had huge issues with Leo Triplet. I also rejected the idea I had misconfigured Gaia as it was ‘always’ working.

In the end I noticed I had 2 versions of SP Gaia instead of non-SP version of DR3 :) since then it started to work again without problems.

Hope this solves your issues.

CS,

Jure

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PaoloMoroni avatar
PaoloMoroni avatar

If you feed the coordinates found with Astap to Pixinsight's Image solver, you will almost always get the right answer.

Regards, Paolo

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Ejo Schrama avatar
Ejo Schrama avatar

Just feed the coordinates of the object manually and make sure that the focal length is correct, if that doesn’t help then something else is going on

Ivan Humeniuk avatar
Ivan Humeniuk avatar

PaoloMoroni · Apr 27, 2026, 03:35 PM

If you feed the coordinates found with Astap to Pixinsight's Image solver, you will almost always get the right answer.

Regards, Paolo

It never worked out that way for me. I even uploaded a photo to the Astrometry.net , it gave me all the parameters I needed, which I entered into the pix image solver, and it still couldn't do anything. I just gave up and started using the online star catalog TYCHO-2. Works like a charm.📷 image.pngimage.png

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alpheratz06 avatar
alpheratz06 avatar

Do the subs stack adequately?

Jeffrey Kieft avatar
Jeffrey Kieft avatar

When I have had issues getting a valid astrometric solution in PixInsight, it has alway boiled down to one of these:

  1. Image Solver is using an online star catalog, rather than the local database. Pointing it to a local database (needs to be configured correctly) often solves the issue.

  2. Initial coordinates are far off. The coordinates extracted from the FITS header should get you close, but for some reason manually entering sometimes helps.

  3. Focal length/pixel scale are incorrect.

  4. Using too many stars. Sometimes, manually limiting the magnitude of stars to 12 or so, rather than allowing it to decide on its own, can help.

  5. Stars have aberrations that are throwing off accurate identification. In this case, running the “Correct only” algorithm in Blur Exterminator before running Image Solve can help.

When I have issues, I check #1-3 first. If that fails, I try #4. If it fails again, I do #5. I have never had it fail after doing all of these. In fact, #1 usually fixes it.

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Andrew Murrell avatar
Andrew Murrell avatar

Were you stacking using WBPP?

Did WBPP do a fast integration due to 150 or more subs stacked?

For some reason, I had Fast integration activated, and all of my plate-solving stopped. I received the same error message.

To check, go to the Lights tab under the WBPP initial window. Look down the list of options on the right to the image integration box. Is Automatic Integration mode ticked? If so, untick the box and try stacking again. Once I did this, everything went back to normal. Stacking did take longer, but I got a better result.

Not sure why this would cause the issue but it does.

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Tony Gondola avatar
Tony Gondola avatar

PI’s solver is just really a diva. I find it has issues when shooting at long FL’s with few stars in the frame. When this happens I go out to ASTAP and it solves every time, go figure.

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Marcin Cikała avatar
Marcin Cikała avatar

Guys!

I don't want to be stubborn, but I still think the problem is with star detection. Jeffrey wrote extensively about this.

FIrst of all if the local catalog is configured incorrectly script will retrieve data from online catalogs. However, looking at the process console, you can see that 153 potentially useful stars were retrieved from the GAIA DR3 catalog. After applying the selection/detection criteria only 17 stars left (!). There's clearly a problem with the detection parameters or picture itself. I'm surprised by the following information that the minimum star size is 32 pixels. With an image scale of 0.43 as/pix, this results in about 14as per star. A bit much and it means that small stars are rejected and only the 17 brightest stars is used. At the end of process information that no star pairs were found for the initial linear transformation is displayed.

Check the result using online catalogs. If the result is similar you'll know where to go.

m.

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