Failure with "center on" feature


Hello all,

I have been new to SGP and have been playing around with its cool tools.

I have been struggling with the “center on” tool after a meridian flip. Before the flip it takes the image, does the flip, then attempts to move back to the original location.

I have it set for within 50 pixels which it usually accomplishes within 2 recenters. However, after the meridian flip it gets “caught” in a location and will continually plate solve, note that it is off, not move, then take a picture, plate solve, not its not in the right place, etc. Until it eventually fails without moving once (I have it set to 6 recenters before failing).

At that point, I hit “center on again” it does another slew and then works perfectly and is usually within 10 pixels.

The rub is that it makes automation a lot harder since I would have to be at the mount for the meridian flip recenter.

Thanks for any help you can provide.


This happen to me on occasion. Usually it is due to the fact that the region I end up in and FOV does not have enough data (good stars) to do the plate solve. Not sure how to solve your problem, I always hang around (or wake up) to make sure SGP gets on target after a flip.It it does not plate solve correctly I simply move the scope to find a good FOV and plate solve and then "center on target."


Bummer! I was hoping to avoid this so that I could get more sleep.

According to platesolve2 it appears to have successfully plate solved but the “slew to new location” just doesn’t happen.

Thanks again for the help.


you should probably mention what mount you have, what driver, etc., and what centering mode you are using.

for me, with an AP mount and sync-based centering, it works flawlessly every time for me. i never have to babysit the mount, ever. but i know on other mounts you need to use a different centering mode, and it requires some tweaking.



I use the Orion atlas pro with EQMOD. The initial centering of the target is flawless. This only happens after a meridian flip and it tries to re-center. I do nothing other than tell it to “center on” again after it fails and it slews the extra 500 pixels or whatever, and everything is perfect.

I think it must be something wrong with how its telling the mount after a failed plate solve to then move the extra 500 pixels to the new location because it just doesn’t move. It plate solves just fine, the mount doesn’t move.

I wish I had better words to describe what is happening.



well almost certainly the initial centering takes more than one move, right?

i suspected it was EQMOD because i know there has been a lot of talk about how to configure EQMOD with SGP for successful meridian flips… meaning, you’re not the first person to have these kinds of problems. i don’t remember the the thread but it’s worth trying to search this forum for EQMOD and meridian or solve or similar keywords, because there’s a lot of info around regarding this.

SGP has multiple centering modes so some may be more appropriate for EQMOD than others…



The other question is what is your meridian flip position? Flipping on the meridian can cause issues generally. I typically choose 10-15 mins past, so there can be no possible mismatch between where the mount and software believe they are with respect to side of pier.
If it is a case of too few stars, one could increase the exposure for the plate solve, which would likely detect more.