Platesolve-resync fails

[stbkaiser]

Hi robin
I was running SharpCap v4.1.14276.0 (X64, 64 bit) (windos 11 pro PC) .
ZWO ASI2400MC Pro camera
SC is connected to my RSt135 mount
When I captured a image and performed Platesolve , SC solves the image .
When I perform Plate solve and resync, it reports fails to solve.
See attached log file.
Any reason you can see why it was failing to platesolve in the "Plate solve and resync' operation.
Thanks
Steve

[admin]

Hi Steve,

the only plate solve failure in that log is at about 23:00:51, where the solving fails because only 13 stars were detected in the image. It's difficult to be sure exactly why the star count was low, but to give context, SharpCap doesn't even try to run the plate solve calculations with less than 12 stars as that's too few. In the 12 to 20 range there's a chance of success, but to have a decent chance you need 20 or more (ideally 50 to 100).

You can just get unlucky and end up on a bare patch of sky, or a bit of cloud can cut out most of the stars at the wrong moment, or maybe the image was captured before the mount fully settled meaning there was trailing of the stars in it. Do you recall what the image looked like at the point that the plate solve failed?

cheers,

Robin

[stbkaiser]

Hi Robin
Sorry . I included the wrong log file.
in this file
Log_2026-05-12T23_34_48-2604
Starting in line
Info 23:36:07.440266 #29
the PLATE SOLVE only call passes with a solution
BUT when I use the "Plate solve and resync' operation
It reports Plate solve failed due to : Failed to find solution

This reproduced multiple times.
PLATE SOLVE only call passes
Plate solve and resync' fails.

Thanks for help on this.
Steve

[admin]

Hi Steve,

that one is easier to explain...

Plate solve only searches the whole sky (although it starts near the mount pointing co-ordinates to try to speed things up).

Plate solve and resync only searches a small(ish) are around the current mount co-ordinates. By default that area is a circly out to 15 degrees distant from the mount co-ordinates - the limit reflects the intended use of the plate solve/resync - finding the target when the mount GOTO has landed you nearby but not in the right place.

In your case, it looks like the mount thinks it is pointing to Dec+87, but the results from the 'plate solve only' shows that the image is of the sky at a declination close to +44 - this is far too far away from the mount for the plate solve and sync to work.

Were you trying to do an initial alignment in this case with the mount co-ordinates badly wrong before the align? If that's the case then you can either increase the search radius from 15 in the plate solving settings, or use a small sequence to achieve that task without increasing the search radius

Code: Select all

SEQUENCE
    SAVE PLATE SOLVE COORDINATES
    SYNC TO SAVED COORDINATES
END SEQUENCE

cheers,

Robin