AZEQ5 and platesolve does not center the target

[rwsmythe]

I was doing some hardware testing last night and decided it was time to hunt down a persistent problem. Specifically, after initial mount power-on and rough slew to Polaris prior to any alignment, platesolving with offset to center target never brings the star within the FOV. If I manually bring the star into the FOV and use the 'click to recenter' feature following a simple platesolve, Polaris ends up leaving the FOV. However, slewing to something else nearby such as Dubhe will usually make the platesolve/offset to center bring the star reasonably close to where it should be. I don't have any logs or screencaps showing the behavior as I thought about it too late. The next time I can get out with a reasonably clear sky I'll work on getting that documentation.

In the meantime, is there any low hanging fruit I can look at to try to correct the issue? A detailed description of my hardware and process is below. I have found that once I have a two star alignment (performed by centering a target and syncing in CdC while synscan is set to 'align with sync') both platesolve with offset to center and platesolve with sync and re-center work fine and will pretty much bring targets almost exactly to the center after a slew.

Hardware:
Mount: AZEQ5 in AltAz mode
Mount Connectivity: ASCOM via SynScan App Pro
Planetarium Software: CdC
Plate Solver: ASTAP
Scope: AT102EDL w/ 0.8x reducer/flatner
Camera: ASI294MC Pro

Procedure:
Verify scope is ~level and ~pointed north
Start Sharpcap, connect camera (I have the auto connect equipment setting OFF)
Start synscan pro
Verify location setting
Turn on and connect mount
Start CdC, verify location setting, and connect mount
Connect mount in Sharpcap
Slew to Polaris
Visually verify scope is slewing to ~Polaris
Platesolve/offset to center -----> unexpected behavior, Polaris does not center or even end up even close to the FOV

[admin]

Hi,

would it be possible to test on some stars away from the celestial pole please? Near the celestial pole the way that the RA/Dec co-ordinates change can introduce this sort of issue. Basically whenever you are fairly well clear of the pole (more than a few degrees away), the celestial co-ordinates change smootly across the image. In close to the pole, weird changes occur like one pixel can be at RA=0 on one side of the pole, and just a few pixels away it can be RA=12 on the other side of the pole. SharpCap's plate solve and recenter tool does not have code to deal with this situation.

Hopefully once you move away from the pole, everything will work much more as expected.

cheers,

Robin

[rwsmythe]

Robin,

That solved the issue perfectly, thanks!

R/
Reid