Question about PixInsight Image Solver

[Tom62e]

Hi all,

Question about PixInsight . . . can PI plate solve a stretched image with ImageSolver?  I ask because ImageSolver always fails on all of my stretched images but never fails on any of my linear images.  So, I'm assuming the answer is that PI can only solve linear images (is this correct?).
 
If so, is there another way to solve stretched images in PixInsight — or perhaps I'm just missing an inconspicuous parameter setting?

Thanks,
Tommy

[Budgie1]

I normally only use the ImageSolver before the stretch, right before I apply SPCC. So, out of curiosity I tried it on a TIFF image which had just been stretched (nothing else done to it) and a completed PNG image. On both images the ImageSolver worked just fine, no errors and no fails.

So, for me anyway, it works with both stretched & unstretched. I make sure I do a search for the target, set the correct focal length & camera pixel size and the date. Normally this is taken from the FITS header, but TIFF images don't seem to transfer this data so the data from the last image is reused and this can cause it to fail.

I hope that helps.  

[Tom62e]

It helps because it rules out the issue being a limitation of PI.  Now I know I need to keep looking for the cause.

FYI - If you ever have an image with no metadata because it was lost after processing, you can always open a single sub - go to images - Fits Headers - select the sub in the drop-down menu - and then drop the instance onto the main image.  It will transfer the metadata from the sub to your main image.

Thanks for the reply.

[Tom62e]

I tried playing with the advanced parameters to include more stars and then again to include less stars and I always get the same error.

This is This is the error message I'm getting.

 

 

 

[ONIKKINEN]

Image solver works with stretched images, jpegs, PNGs, you name it. If the image has stars, it can be solved. Most likely some setting issue then.

Is your pixel size, focal length and coordinates input correctly? Remember that if you have resized the image during processing the "pixel size" is no longer the same as the ones found in your camera and you have to tweak that parameter accordingly.

[Tom62e]

41 minutes ago, ONIKKINEN said:

Image solver works with stretched images, jpegs, PNGs, you name it. If the image has stars, it can be solved. Most likely some setting issue then.

Is your pixel size, focal length and coordinates input correctly? Remember that if you have resized the image during processing the "pixel size" is no longer the same as the ones found in your camera and you have to tweak that parameter accordingly.

Hi there,

 

Thanks for the response.  So just so I understand, is cropping the same as re-sizing?  If so, then I did not know that would change the pixel size.  But then why would it work in a linear image that has been cropped?

Thanks,

Tommy

[ONIKKINEN]

32 minutes ago, Tom62e said:

Hi there,

 

Thanks for the response.  So just so I understand, is cropping the same as re-sizing?  If so, then I did not know that would change the pixel size.  But then why would it work in a linear image that has been cropped?

Thanks,

Tommy

I meant resize as in resample or bin, which is a typical action when processing. Cropping would not matter for arcsec/pixel calculations.

[Tom62e]

24 minutes ago, ONIKKINEN said:

I meant resize as in resample or bin, which is a typical action when processing. Cropping would not matter for arcsec/pixel calculations.

Ok, that's what I thought.  So no, I haven't re-sized it at all.

 

[Budgie1]

Could you post a screenshot of the settings you're using in the main ImageSolver window and list the scope & camera used for the image? 

This may help identify a setting which needs altered.  

[Pompey Monkey]

Yes, please post the image.

Your console output says. "limiting to the 8  brightest stars"

When I plate solve in PI, it usually finds thousands of stars. I don't think eight is sufficient to find a valid and unique solution!

Edited June 12, 2023 by Pompey Monkey
Fat fingers