Failure to run Image Solver on Canon R5 raw or jpg image

Richard Wiggins

Hi Adam, I am not able to get Image Solver to work on a comet image taken with my Canon R5 and 400mm lens. I do not have problems solving images with my CDK24 and STX 16803 setup. I have tried various things and not sure where to go from here, I am entering in the RA/DEC data that I used to send the mount and I doubled this data in TheSkyX. I am using J2000 RA=15:12:18.7,DEC= 60:34:37 and the time I am entering is 12:28:05 as the camera recorded 04:28:05AM PST. Note: For some reason when PixInsight loads the file, it translates the time from the 4AM PST to 20 UT rather than the 12 UT I am changing it to.

Canon FIle: "Shooting Date/Time 1/24/2023 4:28:05 AM"

Pixinsight FITs header: DATE-OBS '2023-01-24T20:28:05' Camera timestamp (UTC)

I have included below some of the erros from Pixinsight. I have included the image as JPG to save data space.

Can you help steer me in the correct direction?

See below for excerps from Image Solver;

Matching stars: done

9 putative star pair matches.

Performing RANSAC: done

* Previous attempt failed - this is try #11

useScaleDifferences=false

* Reference image: Limiting to 15 brightest stars.

* Target image: Limiting to 15 brightest stars.

* Distortion correction: Iteration 1 of 50

Matching stars: done

*** 6 star pair matches found - need at least eight matched stars.

* Previous attempt failed - this is try #12

useScaleDifferences=true

* Reference image: Limiting to 15 brightest stars.

* Target image: Limiting to 15 brightest stars.

* Distortion correction: Iteration 1 of 50

Matching stars: done

*** 0 star pair matches found - need at least eight matched stars.

* Previous attempt failed - this is try #13

useScaleDifferences=false

* Reference image: Limiting to 8 brightest stars.

* Target image: Limiting to 8 brightest stars.

* Distortion correction: Iteration 1 of 50

Matching stars: done

Matching stars: done

913 putative star pair matches.

Performing RANSAC: done

*** Error: Unable to find an initial set of putative star pair matches.

<* failed *>

*** Error: The image could not be aligned with the reference star field.

Please check the following items:

• The initial coordinates should be inside the image.


• The initial resolution should be within a factor of 2 from the correct value.


• If you use an online star catalog through the VizieR service, consider using the Gaia DR3 catalog with local XPSD databases instead.


• If the image has high noise levels, bad tracking, or is poorly focused, you may need to adjust some star detection parameters.

*** Error: Unable to plate solve image: Alignment failed.

This usually happens because the initial parameters are too far from the actual metadata of the image.

BlockHead

Typically the issue here is the plate scale (focal length). You can make the image available and the coordinates you believe are correct as well as the focal length, pixel size, plate scale... etc. 

I am happy to try... it looks like there should not be an issue at all.

-the Blockhead

Richard Wiggins

Thank you Adam! 

I started composing a detailed list for you and found that the pixel size I was using was for a Canon R6 which is 6.x um but the size of the R5 is 4.39um. Changing that fixed the problem. I'm still not sure I understand why Pixinsight converted the 4AM PST time from the Canon to 20 UT. I manually changed it to 12UT and that worked.

Anyway, All is good and I appreciate the response.

Thanks so much!

Rick

BlockHead

Excellent.

That difference in scale was probably just enough to tip the balance...

-the Blockhead